An oscilloscope (informally scope or O-scope) is a type of electronic test instrument that graphically displays varying voltages of one or more signals as a function of time. Their main purpose is capturing information on electrical signals for debugging, analysis, or characterization. The displayed waveform can then be analyzed for properties such as amplitude, frequency, rise time, time interval, distortion, and others. Originally, calculation of these values required manually measuring the waveform against the scales built into the screen of the instrument. Modern digital instruments may calculate and display these properties directly.

Oscilloscopes are used in the sciences, engineering, biomedical, automotive and the telecommunications industry. General-purpose instruments are used for maintenance of electronic equipment and laboratory work. Special-purpose oscilloscopes may be used to analyze an automotive ignition system or to display the waveform of the heartbeat as an electrocardiogram, for instance.

History

Early high-speed visualisations of electrical voltages were made with an electro-mechanical oscillograph.  These gave valuable insights into high speed voltage changes, but had a very low frequency response, and were superseded by the oscilloscope which used a cathode ray tube (CRT) as its display element.
The Braun tube, forerunner of the CRT, was known in 1897, and in 1899 Jonathan Zenneck equipped it with beam-forming plates and a magnetic field for deflecting the trace, and this formed the basis of the CRT. Early cathode ray tubes had been applied experimentally to laboratory measurements as early as the 1920s, but suffered from poor stability of the vacuum and the cathode emitters. V. K. Zworykin described a permanently sealed, high-vacuum cathode ray tube with a thermionic emitter in 1931. This stable and reproducible component allowed General Radio to manufacture an oscilloscope that was usable outside a laboratory setting.
After World War II surplus electronic parts became the basis for the revival of Heathkit Corporation, and a $50 oscilloscope kit made from such parts proved its premiere market success.

Features and uses

An analog oscilloscope is typically divided into four sections: the display, vertical controls, horizontal controls and trigger controls. The display is usually a CRT with horizontal and vertical reference lines called the graticule. CRT displays also have controls for focus, intensity, and beam finder.

The vertical section controls the amplitude of the displayed signal. This section has a volts-per-division (Volts/Div) selector knob, an AC/DC/Ground selector switch, and the vertical (primary) input for the instrument. Additionally, this section is typically equipped with the vertical beam position knob.

The horizontal section controls the time base or "sweep" of the instrument. The primary control is the Seconds-per-Division (Sec/Div) selector switch. Also included is a horizontal input for plotting dual X-Y axis signals. The horizontal beam position knob is generally located in this section.

The trigger section controls the start event of the sweep. The trigger can be set to automatically restart after each sweep, or can be configured to respond to an internal or external event. The principal controls of this section are the source and coupling selector switches, and an external trigger input (EXT Input) and level adjustment.

In addition to the basic instrument, most oscilloscopes are supplied with a probe. The probe connects to any input on the instrument and typically has a resistor of ten times the oscilloscope's input impedance. This results in a 0.1 (‑10×) attenuation factor; this helps to isolate the capacitive load presented by the probe cable from the signal being measured. Some probes have a switch allowing the operator to bypass the resistor when appropriate.

Size and portability
Most modern oscilloscopes are lightweight, portable instruments compact enough for a single person to carry. In addition to portable units, the market offers a number of miniature battery-powered instruments for field service applications. Laboratory grade oscilloscopes, especially older units that use vacuum tubes, are generally bench-top devices or are mounted on dedicated carts. Special-purpose oscilloscopes may be rack-mounted or permanently mounted into a custom instrument housing.

Inputs
The signal to be measured is fed to one of the input connectors, which is usually a coaxial connector such as a BNC or UHF type. Binding posts or banana plugs may be used for lower frequencies.
If the signal source has its own coaxial connector, then a simple coaxial cable is used; otherwise, a specialized cable called a "scope probe", supplied with the oscilloscope, is used. In general, for routine use, an open wire test lead for connecting to the point being observed is not satisfactory, and a probe is generally necessary.
General-purpose oscilloscopes usually present an input impedance of 1 megohm in parallel with a small but known capacitance such as 20 picofarads. This allows the use of standard oscilloscope probes. Scopes for use with very high frequencies may have 50 Ω inputs. These must be either connected directly to a 50 Ω signal source or used with Z0 or active probes.

Less-frequently-used inputs include one (or two) for triggering the sweep, horizontal deflection for X‑Y mode displays, and trace brightening/darkening, sometimes called z'‑axis inputs.

 Probes

Open wire test leads (flying leads) are likely to pick up interference, so they are not suitable for low level signals. Furthermore, the leads have a high inductance, so they are not suitable for high frequencies. Using a shielded cable (i.e., coaxial cable) is better for low level signals. Coaxial cable also has lower inductance, but it has higher capacitance: a typical 50 ohm cable has about 90 pF per meter. Consequently, a one-meter direct (1×) coaxial probe loads a circuit with a capacitance of about 110 pF and a resistance of 1 megohm.

To minimize loading, attenuator probes (e.g., 10× probes) are used. A typical probe uses a 9 megohm series resistor shunted by a low-value capacitor to make an RC compensated divider with the cable capacitance and scope input. The RC time constants are adjusted to match. For example, the 9 megohm series resistor is shunted by a 12.2 pF capacitor for a time constant of 110 microseconds. The cable capacitance of 90 pF in parallel with the scope input of 20 pF and 1 megohm (total capacitance 110 pF) also gives a time constant of 110 microseconds. In practice, there is an adjustment so the operator can precisely match the low frequency time constant (called compensating the probe). Matching the time constants makes the attenuation independent of frequency. At low frequencies (where the resistance of R is much less than the reactance of C), the circuit looks like a resistive divider; at high frequencies (resistance much greater than reactance), the circuit looks like a capacitive divider.

The result is a frequency compensated probe for modest frequencies. It presents a load of about 10 megohms shunted by 12 pF. Such a probe is an improvement, but does not work well when the time scale shrinks to several cable transit times or less (transit time is typically 5 ns). In that time frame, the cable looks like its characteristic impedance, and reflections from the transmission line mismatch at the scope input and the probe causes ringing. The modern scope probe uses lossy low capacitance transmission lines and sophisticated frequency shaping networks to make the 10× probe perform well at several hundred megahertz. Consequently, there are other adjustments for completing the compensation.

Probes with 10:1 attenuation are by far the most common; for large signals (and slightly-less capacitive loading), 100:1 probes may be used. There are also probes that contain switches to select 10:1 or direct (1:1) ratios, but the latter setting has significant capacitance (tens of pF) at the probe tip, because the whole cable's capacitance is then directly connected.

Most oscilloscopes provide for probe attenuation factors, displaying the effective sensitivity at the probe tip. Historically, some auto-sensing circuitry used indicator lamps behind translucent windows in the panel to illuminate different parts of the sensitivity scale. To do so, the probe connectors (modified BNCs) had an extra contact to define the probe's attenuation. (A certain value of resistor, connected to ground, "encodes" the attenuation.) Because probes wear out, and because the auto-sensing circuitry is not compatible between different oscilloscope makes, auto-sensing probe scaling is not foolproof. Likewise, manually setting the probe attenuation is prone to user error. Setting the probe scaling incorrectly is a common error, and throws the reading off by a factor of 10.

Special high voltage probes form compensated attenuators with the oscilloscope input. These have a large probe body, and some require partly filling a canister surrounding the series resistor with volatile liquid fluorocarbon to displace air. The oscilloscope end has a box with several waveform-trimming adjustments. For safety, a barrier disc keeps the user's fingers away from the point being examined. Maximum voltage is in the low tens of kV. (Observing a high voltage ramp can create a staircase waveform with steps at different points every repetition, until the probe tip is in contact. Until then, a tiny arc charges the probe tip, and its capacitance holds the voltage (open circuit). As the voltage continues to climb, another tiny arc charges the tip further.)

There are also current probes, with cores that surround the conductor carrying current to be examined. One type has a hole for the conductor, and requires that the wire be passed through the hole for semi-permanent or permanent mounting. However, other types, used for temporary testing, have a two-part core that can be clamped around a wire. Inside the probe, a coil wound around the core provides a current into an appropriate load, and the voltage across that load is proportional to current. This type of probe only senses AC.

A more-sophisticated probe includes a magnetic flux sensor (Hall effect sensor) in the magnetic circuit. The probe connects to an amplifier, which feeds (low frequency) current into the coil to cancel the sensed field; the magnitude of the current provides the low-frequency part of the current waveform, right down to DC. The coil still picks up high frequencies. There is a combining network akin to a loudspeaker crossover.

Front panel controls

Focus control
This control adjusts CRT focus to obtain the sharpest, most-detailed trace. In practice, focus must be adjusted slightly when observing very different signals, so it must be an external control. The control varies the voltage applied to a focusing anode within the CRT. Flat-panel displays do not need this control.

Intensity control
This adjusts trace brightness. Slow traces on CRT oscilloscopes need less, and fast ones, especially if not often repeated, require more brightness. On flat panels, however, trace brightness is essentially independent of sweep speed, because the internal signal processing effectively synthesizes the display from the digitized data.

Astigmatism
This control may instead be called "shape" or "spot shape". It adjusts the voltage on the last CRT anode (immediately next to the Y deflection plates). For a circular spot, the final anode must be at the same potential as both of the Y-plates (for a centred spot the Y-plate voltages must be the same). If the anode is made more positive, the spot becomes elliptical in the X-plane as the more negative Y-plates will repel the beam. If the anode is made more negative, the spot becomes elliptical in the Y-plane as the more positive Y-plates will attract the beam. This control may be absent from simpler oscilloscope designs or may even be an internal control. It is not necessary with flat panel displays.

Beam finder
Modern oscilloscopes have direct-coupled deflection amplifiers, which means the trace could be deflected off-screen. They also might have their beam blanked without the operator knowing it. To help in restoring a visible display, the beam finder circuit overrides any blanking and limits the beam deflection to the visible portion of the screen. Beam-finder circuits often distort the trace while activated.

Graticule
The graticule is a grid of lines that serve as reference marks for measuring the displayed trace. These markings, whether located directly on the screen or on a removable plastic filter, usually consist of a 1 cm grid with closer tick marks (often at 2 mm) on the centre vertical and horizontal axis. One expects to see ten major divisions across the screen; the number of vertical major divisions varies. Comparing the grid markings with the waveform permits one to measure both voltage (vertical axis) and time (horizontal axis). Frequency can also be determined by measuring the waveform period and calculating its reciprocal.

On old and lower-cost CRT oscilloscopes the graticule is a sheet of plastic, often with light-diffusing markings and concealed lamps at the edge of the graticule. The lamps had a brightness control. Higher-cost instruments have the graticule marked on the inside face of the CRT, to eliminate parallax errors; better ones also had adjustable edge illumination with diffusing markings. (Diffusing markings appear bright.) Digital oscilloscopes, however, generate the graticule markings on the display in the same way as the trace.

External graticules also protect the glass face of the CRT from accidental impact. Some CRT oscilloscopes with internal graticules have an unmarked tinted sheet plastic light filter to enhance trace contrast; this also serves to protect the faceplate of the CRT.

Accuracy and resolution of measurements using a graticule is relatively limited; better instruments sometimes have movable bright markers on the trace. These permit internal circuits to make more refined measurements.

Both calibrated vertical sensitivity and calibrated horizontal time are set in  steps. This leads, however, to some awkward interpretations of minor divisions.

Digital oscilloscopes generate the graticule digitally. The scale, spacing, etc., of the graticule can therefore be varied, and accuracy of readings may be improved.

Timebase controls

These select the horizontal speed of the CRT's spot as it creates the trace; this process is commonly referred to as the sweep. In all but the least-costly modern oscilloscopes, the sweep speed is selectable and calibrated in units of time per major graticule division. Quite a wide range of sweep speeds is generally provided, from seconds to as fast as picoseconds (in the fastest) per division. Usually, a continuously-variable control (often a knob in front of the calibrated selector knob) offers uncalibrated speeds, typically slower than calibrated. This control provides a range somewhat greater than the calibrated steps, making any speed between the steps available.

Holdoff control
Some higher-end analog oscilloscopes have a holdoff control. This sets a time after a trigger during which the sweep circuit cannot be triggered again. It helps provide a stable display of repetitive events in which some triggers would create confusing displays. It is usually set to minimum, because a longer time decreases the number of sweeps per second, resulting in a dimmer trace. See Holdoff for a more detailed description.

Vertical sensitivity, coupling, and polarity controls
To accommodate a wide range of input amplitudes, a switch selects calibrated sensitivity of the vertical deflection. Another control, often in front of the calibrated selector knob, offers a continuously variable sensitivity over a limited range from calibrated to less-sensitive settings.

Often the observed signal is offset by a steady component, and only the changes are of interest. An input coupling switch in the "AC" position connects a capacitor in series with the input that blocks low-frequency signals and DC. However, when the signal has a fixed offset of interest, or changes slowly, the user will usually prefer "DC" coupling, which bypasses any such capacitor. Most oscilloscopes offer the DC input option. For convenience, to see where zero volts input currently shows on the screen, many oscilloscopes have a third switch position (usually labeled "GND" for ground) that disconnects the input and grounds it. Often, in this case, the user centers the trace with the vertical position control.

Better oscilloscopes have a polarity selector. Normally, a positive input moves the trace upward; the polarity selector offers an "inverting" option, in which a positive-going signal deflects the trace downward.

Vertical position control
 The vertical position control moves the whole displayed trace up and down. It is used to set the no-input trace exactly on the center line of the graticule, but also permits offsetting vertically by a limited amount. With direct coupling, adjustment of this control can compensate for a limited DC component of an input.

Horizontal sensitivity control
This control is found only on more elaborate oscilloscopes; it offers adjustable sensitivity for external horizontal inputs. It is only active when the instrument is in X-Y mode, i.e. the internal horizontal sweep is turned off.

Horizontal position control
 The horizontal position control moves the display sidewise. It usually sets the left end of the trace at the left edge of the graticule, but it can displace the whole trace when desired. This control also moves the X-Y mode traces sidewise in some instruments, and can compensate for a limited DC component as for vertical position.

Dual-trace controls

 Each input channel usually has its own set of sensitivity, coupling, and position controls, though some four-trace oscilloscopes have only minimal controls for their third and fourth channels.

Dual-trace oscilloscopes have a mode switch to select either channel alone, both channels, or (in some) an X‑Y display, which uses the second channel for X deflection. When both channels are displayed, the type of channel switching can be selected on some oscilloscopes; on others, the type depends upon timebase setting. If manually selectable, channel switching can be free-running (asynchronous), or between consecutive sweeps. Some Philips dual-trace analog oscilloscopes had a fast analog multiplier, and provided a display of the product of the input channels.

Multiple-trace oscilloscopes have a switch for each channel to enable or disable display of the channel's trace.

Delayed-sweep controls

These include controls for the delayed-sweep timebase, which is calibrated, and often also variable. The slowest speed is several steps faster than the slowest main sweep speed, though the fastest is generally the same. A calibrated multiturn delay time control offers wide range, high resolution delay settings; it spans the full duration of the main sweep, and its reading corresponds to graticule divisions (but with much finer precision). Its accuracy is also superior to that of the display.

A switch selects display modes: Main sweep only, with a brightened region showing when the delayed sweep is advancing, delayed sweep only, or (on some) a combination mode.

Good CRT oscilloscopes include a delayed-sweep intensity control, to allow for the dimmer trace of a much-faster delayed sweep which nevertheless occurs only once per main sweep. Such oscilloscopes also are likely to have a trace separation control for multiplexed display of both the main and delayed sweeps together.

Sweep trigger controls

A switch selects the trigger source. It can be an external input, one of the vertical channels of a dual or multiple-trace oscilloscope, or the AC line (mains) frequency. Another switch enables or disables auto trigger mode, or selects single sweep, if provided in the oscilloscope. Either a spring-return switch position or a pushbutton arms single sweeps.

A trigger level control varies the voltage required to generate a trigger, and the slope switch selects positive-going or negative-going polarity at the selected trigger level.

Basic types of sweep

Triggered sweep

To display events with unchanging or slowly (visibly) changing waveforms, but occurring at times that may not be evenly spaced, modern oscilloscopes have triggered sweeps. Compared to older, simpler oscilloscopes with continuously-running sweep oscillators, triggered-sweep oscilloscopes are markedly more versatile.

A triggered sweep starts at a selected point on the signal, providing a stable display. In this way, triggering allows the display of periodic signals such as sine waves and square waves, as well as nonperiodic signals such as single pulses, or pulses that do not recur at a fixed rate.

With triggered sweeps, the scope blanks the beam and starts to reset the sweep circuit each time the beam reaches the extreme right side of the screen. For a period of time, called holdoff, (extendable by a front-panel control on some better oscilloscopes), the sweep circuit resets completely and ignores triggers. Once holdoff expires, the next trigger starts a sweep. The trigger event is usually the input waveform reaching some user-specified threshold voltage (trigger level) in the specified direction (going positive or going negative—trigger polarity).

In some cases, variable holdoff time can be useful to make the sweep ignore interfering triggers that occur before the events to be observed. In the case of repetitive, but complex waveforms, variable holdoff can provide a stable display that could not otherwise be achieved.

HoldoffTrigger holdoff defines a certain period following a trigger during which the sweep cannot be triggered again. This makes it easier to establish a stable view of a waveform with multiple edges, which would otherwise cause additional triggers.

Example
Imagine the following repeating waveform:

The green line is the waveform, the red vertical partial line represents the location of the trigger, and the yellow line represents the trigger level. If the scope was simply set to trigger on every rising edge, this waveform would cause three triggers for each cycle:

Assuming the signal is fairly high frequency, the scope display would probably look something like this:

On an actual scope, each trigger would be the same channel, so all would be the same color.

It is desirable for the scope to trigger on only one edge per cycle, so it is necessary to set the holdoff at slightly less than the period of the waveform. This prevents triggering from occurring more than once per cycle, but still lets it trigger on the first edge of the next cycle.

Automatic sweep mode
Triggered sweeps can display a blank screen if there are no triggers. To avoid this, these sweeps include a timing circuit that generates free-running triggers so a trace is always visible. This is referred to as "auto sweep" or "automatic sweep" in the controls. Once triggers arrive, the timer stops providing pseudo-triggers. The user will usually disable automatic sweep when observing low repetition rates.

Recurrent sweeps
If the input signal is periodic, the sweep repetition rate can be adjusted to display a few cycles of the waveform. Early (tube) oscilloscopes and lowest-cost oscilloscopes have sweep oscillators that run continuously, and are uncalibrated. Such oscilloscopes are very simple, comparatively inexpensive, and were useful in radio servicing and some TV servicing. Measuring voltage or time is possible, but only with extra equipment, and is quite inconvenient. They are primarily qualitative instruments.

They have a few (widely spaced) frequency ranges, and relatively wide-range continuous frequency control within a given range. In use, the sweep frequency is set to slightly lower than some submultiple of the input frequency, to display typically at least two cycles of the input signal (so all details are visible). A very simple control feeds an adjustable amount of the vertical signal (or possibly, a related external signal) to the sweep oscillator. The signal triggers beam blanking and a sweep retrace sooner than it would occur free-running, and the display becomes stable.

Single sweeps
Some oscilloscopes offer these. The user manually arms the sweep circuit (typically by a pushbutton or equivalent). "Armed" means it's ready to respond to a trigger. Once the sweep completes, it resets, and does not sweep again until re-armed. This mode, combined with an oscilloscope camera, captures single-shot events.

Types of trigger include:
 external trigger, a pulse from an external source connected to a dedicated input on the scope.
 edge trigger, an edge detector that generates a pulse when the input signal crosses a specified threshold voltage in a specified direction. These are the most common types of triggers; the level control sets the threshold voltage, and the slope control selects the direction (negative or positive-going). (The first sentence of the description also applies to the inputs to some digital logic circuits; those inputs have fixed threshold and polarity response.)
 video trigger, also known as TV trigger, a circuit that extracts synchronizing pulses from video formats such as PAL and NTSC and triggers the timebase on every line, a specified line, every field, or every frame. This circuit is typically found in a waveform monitor device, though some better oscilloscopes include this function.
 delayed trigger, which waits a specified time after an edge trigger before starting the sweep. As described under delayed sweeps, a trigger delay circuit (typically the main sweep) extends this delay to a known and adjustable interval. In this way, the operator can examine a particular pulse in a long train of pulses.

Some recent designs of oscilloscopes include more sophisticated triggering schemes; these are described toward the end of this article.

Delayed sweeps
More sophisticated analog oscilloscopes contain a second timebase for a delayed sweep. A delayed sweep provides a very detailed look at some small selected portion of the main timebase. The main timebase serves as a controllable delay, after which the delayed timebase starts. This can start when the delay expires, or can be triggered (only) after the delay expires. Ordinarily, the delayed timebase is set for a faster sweep, sometimes much faster, such as 1000:1. At extreme ratios, jitter in the delays on consecutive main sweeps degrades the display, but delayed-sweep triggers can overcome this.

The display shows the vertical signal in one of several modes: the main timebase, or the delayed timebase only, or a combination thereof. When the delayed sweep is active, the main sweep trace brightens while the delayed sweep is advancing. In one combination mode, provided only on some oscilloscopes, the trace changes from the main sweep to the delayed sweep once the delayed sweep starts, though less of the delayed fast sweep is visible for longer delays. Another combination mode multiplexes (alternates) the main and delayed sweeps so that both appear at once; a trace separation control displaces them. DSOs can display waveforms this way, without offering a delayed timebase as such.

Dual and multiple-trace oscilloscopes
Oscilloscopes with two vertical inputs, referred to as dual-trace oscilloscopes, are extremely useful and commonplace.
Using a single-beam CRT, they multiplex the inputs, usually switching between them fast enough to display two traces apparently at once. Less common are oscilloscopes with more traces; four inputs are common among these, but a few (Kikusui, for one) offered a display of the sweep trigger signal if desired. Some multi-trace oscilloscopes use the external trigger input as an optional vertical input, and some have third and fourth channels with only minimal controls. In all cases, the inputs, when independently displayed, are time-multiplexed, but dual-trace oscilloscopes often can add their inputs to display a real-time analog sum. Inverting one channel while adding them together results in a display of the differences between them, provided neither channel is overloaded. This difference mode can provide a moderate-performance differential input.)

Switching channels can be asynchronous, i.e. free-running, with respect to the sweep frequency; or it can be done after each horizontal sweep is complete. Asynchronous switching is usually designated "Chopped", while sweep-synchronized is designated "Alt[ernate]". A given channel is alternately connected and disconnected, leading to the term "chopped". Multi-trace oscilloscopes also switch channels either in chopped or alternate modes.

In general, chopped mode is better for slower sweeps. It is possible for the internal chopping rate to be a multiple of the sweep repetition rate, creating blanks in the traces, but in practice this is rarely a problem. The gaps in one trace are overwritten by traces of the following sweep. A few oscilloscopes had a modulated chopping rate to avoid this occasional problem. Alternate mode, however, is better for faster sweeps.

True dual-beam CRT oscilloscopes did exist, but were not common. One type (Cossor, U.K.) had a beam-splitter plate in its CRT, and single-ended deflection following the splitter. Others had two complete electron guns, requiring tight control of axial (rotational) mechanical alignment in manufacturing the CRT. Beam-splitter types had horizontal deflection common to both vertical channels, but dual-gun oscilloscopes could have separate time bases, or use one time base for both channels. Multiple-gun CRTs (up to ten guns) were made in past decades. With ten guns, the envelope (bulb) was cylindrical throughout its length. (Also see "CRT Invention" in Oscilloscope history.)

The vertical amplifier
In an analog oscilloscope, the vertical amplifier acquires the signal[s] to be displayed and provides a signal large enough to deflect the CRT's beam. In better oscilloscopes, it delays the signal by a fraction of a microsecond. The maximum deflection is at least somewhat beyond the edges of the graticule, and more typically some distance off-screen. The amplifier has to have low distortion to display its input accurately (it must be linear), and it has to recover quickly from overloads. As well, its time-domain response has to represent transients accurately—minimal overshoot, rounding, and tilt of a flat pulse top.

A vertical input goes to a frequency-compensated step attenuator to reduce large signals to prevent overload. The attenuator feeds one or more low-level stages, which in turn feed gain stages (and a delay-line driver if there is a delay). Subsequent gain stages lead to the final output stage, which develops a large signal swing (tens of volts, sometimes over 100 volts) for CRT electrostatic deflection.

In dual and multiple-trace oscilloscopes, an internal electronic switch selects the relatively low-level output of one channel's early-stage amplifier and sends it to the following stages of the vertical amplifier.

In free-running ("chopped") mode, the oscillator (which may be simply a different operating mode of the switch driver) blanks the beam before switching, and unblanks it only after the switching transients have settled.

Part way through the amplifier is a feed to the sweep trigger circuits, for internal triggering from the signal. This feed would be from an individual channel's amplifier in a dual or multi-trace oscilloscope, the channel depending upon the setting of the trigger source selector.

This feed precedes the delay (if there is one), which allows the sweep circuit to unblank the CRT and start the forward sweep, so the CRT can show the triggering event. High-quality analog delays add a modest cost to an oscilloscope, and are omitted in cost-sensitive oscilloscopes.

The delay, itself, comes from a special cable with a pair of conductors wound around a flexible, magnetically soft core. The coiling provides distributed inductance, while a conductive layer close to the wires provides distributed capacitance. The combination is a wideband transmission line with considerable delay per unit length. Both ends of the delay cable require matched impedances to avoid reflections.

X-Y mode

Most modern oscilloscopes have several inputs for voltages, and thus can be used to plot one varying voltage versus another. This is especially useful for graphing I-V curves (current versus voltage characteristics) for components such as diodes, as well as Lissajous patterns. Lissajous figures are an example of how an oscilloscope can be used to track phase differences between multiple input signals. This is very frequently used in broadcast engineering to plot the left and right stereophonic channels, to ensure that the stereo generator is calibrated properly. Historically, stable Lissajous figures were used to show that two sine waves had a relatively simple frequency relationship, a numerically-small ratio. They also indicated phase difference between two sine waves of the same frequency.

The X-Y mode also lets the oscilloscope serve as a vector monitor to display images or user interfaces. Many early games, such as Tennis for Two, used an oscilloscope as an output device.

Complete loss of signal in an X-Y CRT display means that the beam is stationary, striking a small spot. This risks burning the phosphor if the brightness is too high. Such damage was more common in older scopes as the phosphors previously used burned more easily. Some dedicated X-Y displays reduce beam current greatly, or blank the display entirely, if there are no inputs present.

Z input

Some analogue oscilloscopes feature a Z input. This is generally an input terminal that connects directly to the CRT grid (usually via a coupling capacitor). This allows an external signal to either increase (if positive) or decrease (if negative) the brightness of the trace, even allowing it to be totally blanked. The voltage range to achieve cut-off to a brightened display is of the order of 10–20 volts depending on the CRT characteristics.

An example of a practical application is if a pair of sine waves of known frequency are used to generate a circular Lissajous figure and a higher unknown frequency is applied to the Z input. This turns the continuous circle into a circle of dots. The number of dots multiplied by the X-Y frequency gives the Z frequency. This technique only works if the Z frequency is an integer ratio of the X-Y frequency and only if it is not so large that the dots become so numerous that they are difficult to count.

Bandwidth
As with all practical instruments, oscilloscopes do not respond equally to all possible input frequencies. The range of sinusoid frequencies an oscilloscope can usefully display is referred to as its bandwidth. Bandwidth applies primarily to the Y-axis, though the X-axis sweeps must be fast enough to show the highest-frequency waveforms.

The bandwidth is defined as the frequency at which the sensitivity is 0.707 of the sensitivity at DC or the lowest AC frequency
(a drop of 3 dB). The oscilloscope's response drops off rapidly as the input frequency rises above that point. Within the stated bandwidth the response is not necessarily exactly uniform (or "flat"), but should always fall within a +0 to −3 dB range. One source says there is a noticeable effect on the accuracy of voltage measurements at only 20 percent of the stated bandwidth. Some oscilloscopes' specifications do include a narrower tolerance range within the stated bandwidth.

Probes also have bandwidth limits and must be chosen and used to handle the frequencies of interest properly. To achieve the flattest response, most probes must be "compensated" (an adjustment performed using a test signal from the oscilloscope) to allow for the reactance of the probe's cable.

Another related specification is rise time. This is the time taken between 10% and 90% of the maximum amplitude response at the leading edge of a pulse. It is related to the bandwidth approximately by:

Bandwidth in Hz × rise time in seconds = 0.35.

For example, an oscilloscope with a rise time of 1 nanosecond would have a bandwidth of 350 MHz.

In analog instruments, the bandwidth of the oscilloscope is limited by the vertical amplifiers and the CRT or other display subsystem. In digital instruments, the sampling rate of the analog-to-digital converter (ADC) is a factor, but the stated analog bandwidth (and therefore the overall bandwidth of the instrument) is usually less than the ADC's Nyquist frequency. This is due to limitations in the analog signal amplifier, deliberate design of the anti-aliasing filter that precedes the ADC, or both.

For a digital oscilloscope, a rule of thumb is that the continuous sampling rate should be ten times the highest frequency desired to resolve; for example a 20 megasample/second rate would be applicable for measuring signals up to about 2 MHz. This lets the anti-aliasing filter be designed with a 3 dB down point of 2 MHz and an effective cutoff at 10 MHz (the Nyquist frequency), avoiding the artifacts of a very steep ("brick-wall") filter.

A sampling oscilloscope can display signals of considerably higher frequency than the sampling rate if the signals are exactly, or nearly, repetitive. It does this by taking one sample from each successive repetition of the input waveform, each sample being at an increased time interval from the trigger event. The waveform is then displayed from these collected samples. This mechanism is referred to as "equivalent-time sampling". Some oscilloscopes can operate in either this mode or in the more traditional "real-time" mode at the operator's choice.

Other features

Some oscilloscopes have cursors. These are lines that can be moved about the screen to measure the time interval between two points, or the difference between two voltages. A few older oscilloscopes simply brightened the trace at movable locations. These cursors are more accurate than visual estimates referring to graticule lines.

Better quality general purpose oscilloscopes include a calibration signal for setting up the compensation of test probes; this is (often) a 1 kHz square-wave signal of a definite peak-to-peak voltage available at a test terminal on the front panel. Some better oscilloscopes also have a squared-off loop for checking and adjusting current probes.

Sometimes a user wants to see an event that happens only occasionally. To catch these events, some oscilloscopes—called storage scopes—preserve the most recent sweep on the screen. This was originally achieved with a special CRT, a storage tube, which retained the image of even a very brief event for a long time.

Some digital oscilloscopes can sweep at speeds as slow as once per hour, emulating a strip chart recorder.
That is, the signal scrolls across the screen from right to left. Most oscilloscopes with this facility switch from a sweep to a strip-chart mode at about one sweep per ten seconds. This is because otherwise, the scope looks broken: it's collecting data, but the dot cannot be seen.

All but the simplest models of current oscilloscopes more often use digital signal sampling. Samples feed fast analog-to-digital converters, following which all signal processing (and storage) is digital.

Many oscilloscopes accommodate plug-in modules for different purposes, e.g., high-sensitivity amplifiers of relatively narrow bandwidth, differential amplifiers, amplifiers with four or more channels, sampling plugins for repetitive signals of very high frequency, and special-purpose plugins, including audio/ultrasonic spectrum analyzers, and stable-offset-voltage direct-coupled channels with relatively high gain.

Examples of use

One of the most frequent uses of scopes is troubleshooting malfunctioning electronic equipment. For example, where a voltmeter may show a totally unexpected voltage, a scope may reveal that the circuit is oscillating. In other cases the precise shape or timing of a pulse is important.

In a piece of electronic equipment, for example, the connections between stages (e.g., electronic mixers, electronic oscillators, amplifiers) may be 'probed' for the expected signal, using the scope as a simple signal tracer. If the expected signal is absent or incorrect, some preceding stage of the electronics is not operating correctly. Since most failures occur because of a single faulty component, each measurement can show that some of the stages of a complex piece of equipment either work, or probably did not cause the fault.

Once the faulty stage is found, further probing can usually tell a skilled technician exactly which component has failed. Once the component is replaced, the unit can be restored to service, or at least the next fault can be isolated. This sort of troubleshooting is typical of radio and TV receivers, as well as audio amplifiers, but can apply to quite different devices such as electronic motor drives.

Another use is to check newly designed circuitry. Often, a newly designed circuit misbehaves because of design errors, bad voltage levels, electrical noise etc. Digital electronics usually operate from a clock, so a dual-trace scope showing both the clock signal and a test signal dependent upon the clock is useful. Storage scopes are helpful for "capturing" rare electronic events that cause defective operation.

Oscilloscopes are often used during real-time software development to check, among other things, missed deadlines and worst-case latencies.

Pictures of use

Automotive use
First appearing in the 1970s for ignition system analysis, automotive oscilloscopes are becoming an important workshop tool for testing sensors and output signals on electronic engine management systems, braking and stability systems. Some oscilloscopes can trigger and decode serial bus messages, such as the CAN bus commonly used in automotive applications.

Selection
For work at high frequencies and with fast digital signals, the bandwidth of the vertical amplifiers and sampling rate must be high enough. For general-purpose use, a bandwidth of at least 100 MHz is usually satisfactory. A much lower bandwidth is sufficient for audio-frequency applications only.
A useful sweep range is from one second to 100 nanoseconds, with appropriate triggering and (for analog instruments) sweep delay. A well-designed, stable trigger circuit is required for a steady display. The chief benefit of a quality oscilloscope is the quality of the trigger circuit.

Key selection criteria of a DSO (apart from input bandwidth) are the sample memory depth and sample rate. Early DSOs in the mid- to late 1990s only had a few KB of sample memory per channel. This is adequate for basic waveform display, but does not allow detailed examination of the waveform or inspection of long data packets for example. Even entry-level (<$500) modern DSOs now have 1 MB or more of sample memory per channel, and this has become the expected minimum in any modern DSO. Often this sample memory is shared between channels, and can sometimes only be fully available at lower sample rates. At the highest sample rates, the memory may be limited to a few tens of KB.
Any modern "real-time" sample rate DSO typically has 5–10 times the input bandwidth in sample rate. So a 100 MHz bandwidth DSO would have 500 Ms/s – 1 Gs/s sample rate. The theoretical minimum sample rate required, using SinX/x interpolation, is 2.5 times the bandwidth.

Analog oscilloscopes have been almost totally displaced by digital storage scopes except for use exclusively at lower frequencies. Greatly increased sample rates have largely eliminated the display of incorrect signals, known as "aliasing", which was sometimes present in the first generation of digital scopes. The problem can still occur when, for example, viewing a short section of a repetitive waveform that repeats at intervals thousands of times longer than the section viewed (for example a short synchronization pulse at the beginning of a particular television line), with an oscilloscope that cannot store the extremely large number of samples between one instance of the short section and the next.

The used test equipment market, particularly on-line auction venues, typically has a wide selection of older analog scopes available. However it is becoming more difficult to obtain replacement parts for these instruments, and repair services are generally unavailable from the original manufacturer. Used instruments are usually out of calibration, and recalibration by companies with the necessary equipment and expertise usually costs more than the second-hand value of the instrument.

, a 350 MHz bandwidth (BW), 2.5 gigasamples per second (GS/s), dual-channel digital storage scope costs about US$7000 new.

On the lowest end, an inexpensive hobby-grade single-channel DSO could be purchased for under $90 as of June 2011. These often have limited bandwidth and other facilities, but fulfill the basic functions of an oscilloscope.

Software
Many oscilloscopes today provide one or more external interfaces to allow remote instrument control by external software. These interfaces (or buses) include GPIB, Ethernet, serial port, USB and Wi-Fi.

Types and models

The following section is a brief summary of various types and models available. For a detailed discussion, refer to the other article.

Cathode-ray oscilloscope (CRO)

The earliest and simplest type of oscilloscope consisted of a cathode ray tube, a vertical amplifier, a timebase, a horizontal amplifier and a power supply. These are now called "analog" scopes to distinguish them from the "digital" scopes that became common in the 1990s and later.

Analog scopes do not necessarily include a calibrated reference grid for size measurement of waves, and they may not display waves in the traditional sense of a line segment sweeping from left to right. Instead, they could be used for signal analysis by feeding a reference signal into one axis and the signal to measure into the other axis. For an oscillating reference and measurement signal, this results in a complex looping pattern referred to as a Lissajous curve. The shape of the curve can be interpreted to identify properties of the measurement signal in relation to the reference signal, and is useful across a wide range of oscillation frequencies.

 Dual-beam oscilloscope

The dual-beam analog oscilloscope can display two signals simultaneously. A special dual-beam CRT generates and deflects two separate beams. Multi-trace analog oscilloscopes can simulate a dual-beam display with chop and alternate sweeps—but those features do not provide simultaneous displays. (Real time digital oscilloscopes offer the same benefits of a dual-beam oscilloscope, but they do not require a dual-beam display.) The disadvantages of the dual trace oscilloscope are that it cannot switch quickly between traces, and cannot capture two fast transient events. A dual beam oscilloscope avoids those problems.

Analog storage oscilloscope

Trace storage is an extra feature available on some analog scopes; they used direct-view storage CRTs. Storage allows a trace pattern that normally would decay in a fraction of a second to remain on the screen for several minutes or longer. An electrical circuit can then be deliberately activated to store and erase the trace on the screen.

Digital oscilloscopes

While analog devices use continually varying voltages, digital devices use numbers that correspond to samples of the voltage. In the case of digital oscilloscopes, an analog-to-digital converter (ADC) changes the measured voltages into digital information.

The digital storage oscilloscope, or DSO for short, is the standard type of oscilloscope today for the majority of industrial applications, and thanks to the low costs of entry-level oscilloscopes even for hobbyists. It replaces the electrostatic storage method in analog storage scopes with digital memory, which stores sample data as long as required without degradation and displays it without the brightness issues of storage-type CRTs. It also allows complex processing of the signal by high-speed digital signal processing circuits.

A standard DSO is limited to capturing signals with a bandwidth of less than half the sampling rate of the ADC (called the Nyquist limit). There is a variation of the DSO called the digital sampling oscilloscope which can exceed this limit for certain types of signal, such as high-speed communications signals, where the waveform consists of repeating pulses. This type of DSO deliberately samples at a much lower frequency than the Nyquist limit and then uses signal processing to reconstruct a composite view of a typical pulse.

Mixed-signal oscilloscopes
A mixed-signal oscilloscope (or MSO) has two kinds of inputs: a small number of analog channels (typically two or four), and a larger number of digital channels (typically sixteen). It provides the ability to accurately time-correlate analog and digital channels, thus offering a distinct advantage over a separate oscilloscope and logic analyser. Typically, digital channels may be grouped and displayed as a bus with each bus value displayed at the bottom of the display in hexadecimal or binary. On most MSOs, the trigger can be set across both analog and digital channels.

Mixed-domain oscilloscopes
A mixed-domain oscilloscope (MDO) is an oscilloscope that comes with an additional RF input which is solely used for dedicated FFT-based spectrum analyzer functionality. Often, this RF input offers a higher bandwidth than the conventional analog input channels. This is in contrast to the FFT functionality of conventional digital oscilloscopes, which use the normal analog inputs.
Some MDOs allow time-correlation of events in the time domain (like a specific serial data package) with events happening in the frequency domain (like RF transmissions).

Handheld oscilloscopes

Handheld oscilloscopes are useful for many test and field service applications. Today, a handheld oscilloscope is usually a digital sampling oscilloscope, using a liquid crystal display.

Many handheld and bench oscilloscopes have the ground reference voltage common to all input channels. If more than one measurement channel is used at the same time, all the input signals must have the same voltage reference, and the shared default reference is the "earth". If there is no differential preamplifier or external signal isolator, this traditional desktop oscilloscope is not suitable for floating measurements. (Occasionally an oscilloscope user breaks the ground pin in the power supply cord of a bench-top oscilloscope in an attempt to isolate the signal common from the earth ground. This practice is unreliable since the entire stray capacitance of the instrument cabinet connects into the circuit. It is also a hazard to break a safety ground connection, and instruction manuals strongly advise against it.)

Some models of oscilloscope have isolated inputs, where the signal reference level terminals are not connected together. Each input channel can be used to make a "floating" measurement with an independent signal reference level. Measurements can be made without tying one side of the oscilloscope input to the circuit signal common or ground reference.

The isolation available is categorized as shown below:

PC-based oscilloscopes

Some digital oscilloscope rely on a PC platform for display and control of the instrument. This can be in the form of a standalone oscilloscope with internal PC platform (PC mainboard), or as external oscilloscope which connects through USB or LAN to a separate PC or laptop.

Related instruments
A large number of instruments used in a variety of technical fields are really oscilloscopes with inputs, calibration, controls, display calibration, etc., specialized and optimized for a particular application. Examples of such oscilloscope-based instruments include waveform monitors for analyzing video levels in television productions and medical devices such as vital function monitors and electrocardiogram and electroencephalogram instruments. In automobile repair, an ignition analyzer is used to show the spark waveforms for each cylinder. All of these are essentially oscilloscopes, performing the basic task of showing the changes in one or more input signals over time in an X‑Y display.

Other instruments convert the results of their measurements to a repetitive electrical signal, and incorporate an oscilloscope as a display element. Such complex measurement systems include spectrum analyzers, transistor analyzers, and time domain reflectometers (TDRs). Unlike an oscilloscope, these instruments automatically generate stimulus or sweep a measurement parameter.

See also

 Eye pattern
 Phonodeik
 Tennis for Two'', an oscilloscope game
 Time-domain reflectometry
 Vectorscope
 Waveform monitor

References

External links

 The Cathode Ray Tube site
 Virtual Oscilloscope Museum

Electronic test equipment
Measuring instruments
Laboratory equipment
Electronics work tools
American inventions
German inventions


Gaston Tremblay (April 16, 1924 – July 11, 1998) was a politician in Quebec, Canada and a Member of the Legislative Assembly of Quebec (MLA).

Background

He was born in Quebec City on April 16, 1924 and became a physician.

Mayor

Tremblay served as Mayor of Beauport, Quebec from 1961 to 1970.

Member of the legislature

He unsuccessfully ran as a Union Nationale candidate in the 1962 election in the provincial district of Quebec County.  Tremblay was elected to the Legislative Assembly of Quebec in the 1966 election and represented the district of Montmorency.

He crossed the floor on October 30, 1968 to sit as an Independent.  He then joined the Parti nationaliste chrétien, and then in 1969, he joined the Ralliement créditiste and became its first sitting member in the provincial legislature.

Tremblay ran as a Ralliement créditiste candidate and was defeated in the 1970 and 1973 elections.

Electoral history

In Montmorency (provincial electoral district)

References

See also
 History of Quebec

1924 births
1998 deaths
Mayors of places in Quebec
Politicians from Quebec City
Ralliement créditiste du Québec MNAs
Union Nationale (Quebec) MNAs
Université Laval alumni


Erich Hohagen (9 January 1915 – 8 March 1990) was a German general in the Bundeswehr. During World War II, he served as a fighter pilot in the Luftwaffe. A fighter ace, Hohagen was credited with 56 aerial victories and was a recipient of the Knight's Cross of the Iron Cross, the highest award in the military and paramilitary forces of Nazi Germany during World War II.

Career
Hohagen claimed his first aerial victory, a Royal Air Force (RAF) Supermarine Spitfire over Southern England, on 5 July 1940. On 20 February 1941, Hohagen was appointed Staffelkapitän (squadron leader) of 4. Staffel of Jagdgeschwader 51 (JG 51—51st Fighter Wing). He succeeded Oberleutnant Josef Fözö who was promoted to command II. Gruppe of JG 51.

Operation Barbarossa
II. Gruppe of JG 51 was withdrawn from the English Channel in early June 1941 and ordered to Dortmund where the unit was reequipped with the Messerschmitt Bf 109 F series. On 10 June, II. Gruppe began transferring east and was located at Siedlce. On 22 June, German forces launched Operation Barbarossa, the German invasion of the Soviet Union. JG 51, under the command of Oberstleutnant Werner Mölders, was subordinated to II. Fliegerkorps (2nd Air Corps), which as part of Luftflotte 2 (Air Fleet 2). JG 51 area of operation during Operation Barbarossa was over the right flank of Army Group Center in the combat area of the 2nd Panzer Group as well as the 4th Army.

On the first day of the invasion, Hohagen shot down three Soviet SB-2 bombers in the space of five minutes. In August, he was given command of II. Gruppe after its former acting commander Hauptmann Hubertus von Bonin was wounded on 8 August. On 4 September, Hohagen was shot down in his Messerschmitt Bf 109 F-2 (Werknummer 9211—factory number) by Soviet fighters near Bryansk. Wounded, he transferred command of II. Gruppe to Oberleutnant Hartmann Grasser. Hohagen received the Knight's Cross of the Iron Cross () on 5 October 1941, after 30 victories.

In January 1943, Hohagen was posted to Jagdgeschwader 2 "Richthofen" (JG 2—2nd Fighter Wing), taking command of its 2. Staffel. The Staffel was subordinated to III. Gruppe of JG 2 headed by Hauptmann Egon Mayer. On 7 April, Hohagen was transferred to Jagdgeschwader 27 (JG 27—27th Fighter Wing) where he was appointed Gruppenkommandeur (group commander) of I. Gruppe. He succeeded Hauptmann Hans-Joachim Heinecke who temporarily led the Gruppe after Hauptmann Heinrich Setz had been killed in action on 13 March. On 1 June, Hohagen became a victim of friendly fire when he was shot down in his Bf 109 G-6 (Werknummer 16391)  north of Marquise, a village approximately  north-northeast of Boulogne-sur-Mer. He successfully bailed out, taking to his parachute, but was injured in the incident. The pilot that shot him down was Hauptmann Wilhelm Steinmann, also from JG 27, who misidentified Hohagen's Bf 109 for a Spitfire fighter. Due to his injuries, Hohagen was temporarily replaced by Hauptmann Hans Remmer before Hauptmann Ludwig Franzisket officially took command of I. Gruppe of JG 27 on 15 July.

Hohagen was appointed Gruppenkommandeur of I. Gruppe of JG 2 in August 1943. He replaced Major Helmut-Felix Bolz who was transferred. On 16 September 1943, Hohagen, was piloting an Focke Wulf Fw 190 A-6 fighter (Werknummer 550532) when his aircraft was hit by the defensive fire of a Boeing B-17 Flying Fortress bomber. Hohagen was again wounded and made a forced landing near Rennes, France. On 28 September 1944, Hohagen was severely injured, sustaining a skull fracture, when the engine of his Fw 190 A-8 (Werknummer 171559) failed, resulting in a forced landing near the airfield at Merzhausen. He was succeeded by Major Walter Matoni as commander of I. Gruppe.

Flying the Messerschmitt Me 262
In late 1944, Hohagen was posted to III. Gruppe of Ergänzungs-Jagdgeschwader 2 (EJG 2—2nd Supplementary Training Wing), a training unit based at Lechfeld Airfiled. There, he learned to fly the new Messerschmitt Me 262 jet aircraft. He was then posted to Jagdgeschwader 7 "Nowotny" (JG 7—7th Fighter Wing) "Nowotny", the first operational jet fighter wing which was named after Walter Nowotny. Kommando Nowotny had been assessing the Me 262 under operational conditions. Nowotny himself was killed in action while flying the Me 262 on 8 November. On 12 November, the Oberkommando der Luftwaffe (OKL—Air Force High Command) ordered JG 7 to be equipped with the Me 262 and Oberst Johannes Steinhoff became its first Geschwaderkommodore (wing commander). On 19 November, the remnants of Kommando Nowotny became the nucleus of III. Gruppe of JG 7. Placed under the command of Hohagen, III. Gruppe began assembling aircraft and personnel at Lechfeld Air Field. In the latter months of 1944 Hohagen helped to convert pilots to the new jets. On 21 January, Steinhoff was replaced by Major Theodor Weissenberger as Geschwaderkommodore of JG 7, while Hohagen was replaced by Major Rudolf Sinner as Gruppenkommandeur of III. Gruppe.

On 24 February 1945, Generalleutnant Adolf Galland and Steinhoff recruited Hohagen and Major Karl-Heinz Schnell from hospital to join the new Jagdverband 44 (JV 44—44th Fighter Detachment) forming at Brandenburg-Briest. Galland had received permission to create and staff the unorthodox fighter group from Luftwaffe Chief, Reichsmarschall Hermann Göring. JV 44 received its first Me 262 aircraft by 14 March. On 31 March, JV 44 moved to Munich-Riem Airfield.

Hohagen became the Technical Officer for JV 44 and assisted with the conversion of newly arriving pilots to the Me 262. The unit transferred to München-Riem on 31 March 1945.
He served as JV 44's Technical Officer until the crash of Steinhoff on 18 April 1945, and Hohagen replaced the injured Steinhoff as the unit's Einsatzchef (Operations Chief).

On 28 April, moved to JV 44 Maxglan Airfiel, near Salzburg. There they surrendered to U.S. forces on 4 May. Hohagen and other pilots were taken to a makeshift prisoner of war camp near Bad Aibling. Five days later, a U.S. officer was looking for JV 44 pilots and Hohagen, Schnell, Gerhard Barkhorn, Walter Krupinski, and Waldemar Wübke stepped up.

Later life and service
Following World War II, Hohagen joined the newly created German Air Force, at the time referred to as the Bundesluftwaffe. On 30 March 1957, he was given command of 2.  (2nd training squadron) of  (FFS S—Pilot Training School "S") at Memmingen Air Field. He led this training unit until 31 March 1958. From November 1959 to October 1961, he commanded Jagdgeschwader 72 as Geschwaderkommodore, a unit which in October 1964 became Jagdbombergeschwader 43 (JaboG 43—43rd Fighter Bomber Wing). He was succeeded by Oberstleutnant Friedrich Obleser in this capacity. On 16 February 1963, Hohagen replaced Oberst Herbert Wehnelt as commander of the  (WaSLw 10—Air Force Weapons School 10). He served in the role until 15 August 1967 when he was succeeded by Oberst Ulrich Pieper. In April 1968, Hohagen was promoted to Brigadegeneral (brigadier general). Until 30 September 1971, he served as department chief of  (Armaments and Weapon Systems) in the  (German Air Staff ). He died on 8 March 1990 in Jever.

Summary of career

Aerial victory claims
According to US historian David T. Zabecki, Hohagen was credited with 56 aerial victories. Obermaier also lists him with 56 aerial victories claimed in over 500 combat missions. This figure includes 20 claims on the Eastern Front, and 36 on the Western Front, 13 of them being four-engined bombers and one while flying the Me 262 jet fighter. Mathews and Foreman, authors of Luftwaffe Aces — Biographies and Victory Claims, researched the German Federal Archives and state that he claimed at least 49 aerial victories, plus two further unconfirmed claims. This number includes 20 on the Eastern Front and more than 29 on the Western Front, including at least eight four-engined bombers.

Victory claims were logged to a map-reference (PQ = Planquadrat), for example "PQ 14 West 3884". The Luftwaffe grid map () covered all of Europe, western Russia and North Africa and was composed of rectangles measuring 15 minutes of latitude by 30 minutes of longitude, an area of about . These sectors were then subdivided into 36 smaller units to give a location area  in size.

Awards
 Iron Cross (1939) 2nd and 1st Class
 Knight's Cross of the Iron Cross on 5 October 1941 as Oberleutnant and Staffelkapitän of the 4./Jagdgeschwader 51
 German Cross in Gold on 25 December 1943 as Hauptmann in the II./Jagdgeschwader 51.

Notes

References

Citations

Bibliography

1915 births
1990 deaths
Luftwaffe pilots
German World War II flying aces
Military personnel from the Rhine Province
Recipients of the Gold German Cross
Recipients of the Knight's Cross of the Iron Cross
Bundeswehr generals
Brigadier generals of the German Air Force
Military personnel from North Rhine-Westphalia


The Australian Film Critics Association (AFCA), formerly Melbourne Film Critics' Forum, is an Australian professional association for film critics, reviewers and journalists who work in the media, based in Melbourne. It is a member of the International Federation of Film Critics (FIPRESCI).

History
Formed in 1996, AFCA began as the Melbourne Film Critics' Forum, expanding to a national organisation in 2004. In the same year, AFCA became an Australian representative of the International Federation of Film Critics (FIPRESCI), which comprises the national organisations of professional film critics and film journalists from around the world. FIPRESCI has members in more than 50 countries worldwide. AFCA helped to establish the first FIPRESCI jury at the Adelaide Film Festival.

AFCA's members, several of whom contribute to internationally recognised media outlets, are professional film critics, film reviewers and film journalists, from all media forums, who provide informed discussion, analysis and comment on Australian and world cinema. Here are some of them: Adam Ross, Lachlan Marks, Alan James, Laura Bennett, Alex Thomas, Lawrence Barber, Alexandra Heller-Nicholas, Lee Zachariah, Lisa Thatcher, Ashley Beks, Luke Buckmaster, Marcella Papandrea, Bede Jermyn, Madeleine Swain, Mark Lavercombe, Cameron Williams, Matthew Toomey, Carol Van Opstal, Nicholas Brodie, Paul Turner, Peter Krausz, Richard Alaba, David O'Connell, etc. The body supports both mainstream and independent cinema and highlights significant or challenging films.

Film awards

On 22 January 2008, AFCA announced the results of its inaugural Film Awards for 2007. The awards span four categories comprising Best Australian Film, Best Overseas Film, Best Documentary and Best Unreleased Film (in Australia at the time of the awards). The winning and commended films granted AFCA film awards are:

In 2011 acting awards were introduced and the Best Unreleased Film category was discontinued.

Writing awards
In conjunction with its 2009 film awards, AFCA announced the results of its inaugural writing awards. The categories and winners are:

See also
List of film awards

References

External links

Australian film critics associations
1996 establishments in Australia


Giovanni Tommasi Ferroni (born November 12, 1967 in Rome) is an Italian magic realism artist specializing in fantasy painting.

Biography
Ferroni was born into a family of Tuscan artists, including his father Riccardo, grandfather Leone, and uncle Marcello from Pietrasanta. Ferroni's sister Elena was also a painter with whom Ferroni held joint exhibitions early on in his career.

In 1986, after graduating high school, he joined his father's atelier and studied at the Rome University 'La Sapienza'. His paintings depict a fantasy world that is inhabited by all kinds of mythological, historical and contemporary creatures.

Exhibitions
 1989 Galleria AMG, Alassio (Italy)
 1991 Galleria Il Gabbiano, Rome (Italy)
 1995 Galleria L´Indicatore, Rome
 1997 Group exhibition European Figurative Art Steltman Galleries, Amsterdam
 1997 Steltman Galleries, Amsterdam
 1997 Galleria Il Gabbiano, Rome
 1998 Steltman Galleries, New York
 1998 Steltman Galleries, Amsterdam
 2000 Steltman Galleries, Amsterdam
 2002 Museo Sandro Parmeggiani, Ferrara (Italy)
 2002 Steltman Galleries, Amsterdam
 2003 Steltman Galleries, Amsterdam
 2004 Galerie Il Tempietto, Brindisi
 2005 Steltman Galleries, Amsterdam
 2006 February - March, Jan van der Togt Museum, Amstelveen
 2006 April, Gallery Davico, Torino
 2007 Museo Sandro Parmeggiani, Ferrara (Italy)
 2007 Tecna, Milaan (Italy)
 2007 Palazzo Antinori 'Per ... Bacco', Florence (Italy)
 2007 Censa (Italy)
 2007 August, Mongolia
 2007 Steltman Galleries, Amsterdam
 2011 Selective Art Paris

References

External links

 http://www.tommasiferroni.it/Italiaanse
 Tekne
 Tommasi Ferroni WebSite of Steltman Galleries.
 http://www.selective-artparis.com

Living people
1967 births
20th-century Italian painters
20th-century Italian male artists
Painters from Rome
Italian male painters


Elisabeth Ingvaldsen (born 22 July 1973) is a Norwegian orienteering competitor and World champion. She won a gold medal in the 1999 World Orienteering Championships with the Norwegian relay team. She received a silver medal in 1997 and bronze medals in 2001, 2003 and 2004.

She won an individual bronze medal in sprint at the 2004 World Orienteering Championships.

References

External links

1973 births
Living people
Norwegian orienteers
Female orienteers
Foot orienteers
World Orienteering Championships medalists
Competitors at the 2001 World Games
Junior World Orienteering Championships medalists


Commandant Gabriel Auguste Ferdinand Ducuing (22 December 1885 – 25 May 1940) was an officer in the French Navy of the First and Second World Wars.

Life

Early life
He was the son of a second cousin of Ferdinand Foch. Aiming for the merchant marine, he embarked in 1904 as "pilotin" on the three-masted "Cérès". Called to carry out his military service in 1907, he served on board the battleships "Brennus" and "Bouvet". On returning to the merchant fleet, he was promoted lieutenant in the course of 1908 and captain in the course of 1911. He sailed successively on several steamships, all the while taking the time to learn four foreign languages and to study for a law degree.

First World War
At the outbreak of war in July 1914 he was the second captain of a steamship, but he soon decided to leave the merchant navy to join the infantry chasseurs to defend his country. Named sous lieutenant in December, he could not bear the static life of the trenches and moved to the nascent French Air Force, first as an observer-corps officer, then (briefly in July 1915) as a pilot. In July 1915 he returned to the Navy with a commission, captaining an  auxiliary vessel. Assigned to maritime aviation at Dunkerque then at Venice (Italy), he immediately became noted for his brilliant qualities as a trainer. After carrying out many observation and bombing missions, he was injured in battle, mentioned in despatches by the French and Italian navies and knighted by the king of Italy. Promoted enseigne de vaisseau de 1ère classe in the reserve in July 1916, he was moved to train fighter pilots at Pau, where, unfortunately, an accident rendered him unfit to pilot a plane himself. Made a knight of the Légion d’honneur in January 1917 at only 32 years old, he was again stationed at Dunkerque as second in command of its center of maritime aviation. However, finding this post insufficiently "combattant", he had himself made a balloon observer on and, on 1 October, took command of the centre at Le Havre, where he remained up until July 1918. Promoted lieutenant de vaisseau in the reserve, he was then put on attachment (because of his long training as captain) as liaison officer to the under secretary of state to the merchant navy until his demobilization in April 1919.

Inter-war
At the end of the war he did not rejoin the merchant-fleet, instead becoming a ship owner. Marked by the conflict, he remained a particularly active officer in the naval reserve. On 9 July 1925, replying to the call of the general delegate of the National Union of the Officers of the Reserve (Union Nationale des Officiers de Réserve), he combined with some friends to form (within the UNOR) the 5th commission made up of the sailors' vows at the congress of Belfort. This later became the general assembly component of the ACORAM (Central Association of the Officers of Reserve of the Army, or Association Centrale des Officiers de Réserve de l’Armée de Mer), of which Ducuing was naturally elected president, and which still remained close to UNOR.

On the president's suggestion, Ducuing, the French Navy in June 1927 created training centres for reserve officers, that will become accessible to naval NCOs from 1931. In April 1928, Ducuing's eminent services to the state saw him promoted to be an officer of the légion d’honneur. In liaison with the Union of Fighting Sailors (Union des Marins Combattants, UMC) of Paris, he worked for the creation, on 23 February 1930, of the Federation of the Associations of Old Fighting Sailors (Fédération des Associations de Marins Anciens Combattants, FAMAC) that would become the FAMMAC. Equally down to him is the creation of the Central Association of the Non-Commissioned Officers of the Naval Reserve (Association Centrale des Officiers Mariniers de Réserve de l’Armée de Mer, or ACOMAR). At his request, in 1931 the Navy created courses for improving the instruction of non-commissioned officers in the naval reserve. Promoted capitaine de corvette in April 1932, he reached the normal retirement age in 1934 but at his own request remained in the reserves and postponed retirement until December 1942, when he would be 57.

Second World War

In September 1939, Ducuing took command of the battery of D.C.A. (défense contre aéronefs, or anti-aircraft group) of the Croix Faron at Toulon. At the end of January 1940, the French Admiralty was anxious to observe and maintain free passage along the Pas-de-Calais coast, and so set up a coastal battery at Cap Gris-Nez. Ducuing was charged with commanding and organizing this battery from March 1940. He had 3 officers and around 100 men under him, with only twenty rifles and six revolvers between them. On 22 May, facing the German offensive as it closed in on him, with the weak means at his disposal he organized an advanced position of 24 men of which he took personal command. When practically encircled, commandant Ducuing and his men completely destroyed a German column made up of a small number of side-cars, a light tank and two armored cars. In the evening, he refused a surrender proposed to him by the Germans. In the night of 23 to 24 May the French destroyer Chacal was crippled by German bombs and grounded nearby, with some of the wounded sailors joining Ducuing's group.

During the night of 24 to 25 May, he organized the evacuation by sea of the sailors by dredger. On 25 May 1940, at 9am, the German armour under Guderian were no more than 200 metres from Ducuing's post on Cap Gris-Nez. Having run out of munitions, commandant Ducuing destroyed the artillery and machine guns and gave the order to his men to withdraw. Remaining at his post alone, he went to the mast of the base, hoisted the French colors and was killed by a short burst of automatic weapon fire.

Honours
 1915 - Italian knighthood
 January 1917 - knight of the Légion d’honneur
 April 1928 - officer of the Légion d’honneur
 May/June 1940 - Posthumously made capitaine de frégate on (with the navy especially waiving its rule forbidding all posthumous promotions for him), and a brilliant citation in the ordre de l’armée.
 In May 1952, the secretary of state to the navy inaugurated a stela at Cap Gris-Nez in memory of him and the fallen sailors under his command.
 The   is named after him.

External links
  ACORAM - biography
  Memorial to the dead sailors of France

Military personnel from Paris
French Navy officers
French military personnel killed in World War II
World War II in the Pas-de-Calais
French military personnel of World War I
French Navy personnel of World War II
French Army officers
Naval aviators
French Air and Space Force personnel
1885 births
1940 deaths
Deaths by firearm in France


Olavi Litmanen (born 17 April 1945) is a Finnish former international footballer who played as a forward. He spent his career with Reipas Lahti in Mestaruussarja and Lahden Palloseura in lower divisions.

He won 5 Finnish Cup winners' medals with Reipas, 1964, 1972, 1973, 1974 and 1978.

Personal life
Litmanen married a player of the Reipas women's team. He is the father of the Finnish international footballer Jari Olavi Litmanen who also began his career with Reipas.

References

1945 births
Living people
People from Parikkala
Finnish men's footballers
Men's association football forwards
Finland men's international footballers
Sportspeople from South Karelia


The following are International rankings of France.

Cities
gaWC Inventory of World Cities, 1999: :Paris alpha world city

Economic
 The Wall Street Journal and The Heritage Foundation: Index of Economic Freedom 2007, ranked 45 out of 157 countries
International Monetary Fund: GDP (nominal) per capita 2006,  out of 182 countries
International Monetary Fund: GDP (nominal) 2006, ranked 5 out of 181 countries
List of countries by GDP - official exchange rate 2019, ranked 8, out of 226 countries
World Economic Forum: Global Competitiveness Index 2006–2007, ranked 18 out of 125 countries
World Bank: Ease of Doing Business Index, ranked 31 out of 178 countries
World Tourism Organization: World Tourism rankings 2008, ranked 1 in tourist arrivals
Fortune Global 500 2010, with 39 worldwide corporations, France has the third largest number of wealthiest corporations out of 32 countries

Environmental
Yale University: Environmental Sustainability Index 2005, ranked 36 out of 146 countries
New Economics Foundation: Happy Planet Index 2006, ranked 129 out of 178 countries

Globalization
KOF: Globalization Index 2007, ranked 6 out of 122 countries
 A.T. Kearney/Foreign Policy Magazine: Globalization Index 2006, ranked 23 out of 62 countries

Military
 Ranked 5th by military expenditures out of 170 countries.
 CSIS: active troops, ranked 21st out of 166 countries

Political
 Transparency International: Corruption Perceptions Index 2007, ranked 19 out of 179 countries
Reporters Without Borders: Worldwide press freedom index 2007, ranked 31 out of 169 countries
Economist Intelligence Unit: Democracy Index 2007, ranked 24 out of 167 countries
Fund for Peace and Foreign Policy magazine: Failed States Index 2007, ranked 157 out of 177 countries

Social
Economist Intelligence Unit: Quality-of-life index 2005, ranked 25 out of 108 countries
 UN: Human Development Index 2007, ranked 8 out of 177 countries
Population ranked 19 out of 221 countries

Technological
Economist Intelligence Unit e-readiness rankings 2007, ranked 22 out of 69 countries
The World Factbook: number of Internet users, ranked 10 out of 80 countries

International rankings

See also

Lists of countries
Lists by country
List of international rankings

References

France


Gail Roberta Martin (née Zuckman, born 1944) is an American biologist. She is professor emerita in the Department of Anatomy, University of California, San Francisco. She is known for her pioneering work on the isolation of pluripotent stem cells from normal embryos, for which she coined the term ‘embryonic stem cells’. She is also widely recognized for her work on the function of Fibroblast Growth Factors (FGFs) and their negative regulators in vertebrate organogenesis. She and her colleagues also made valuable contributions to gene targeting technology.

Personal life and education
Martin grew up in The Bronx, New York, the only child of a pharmacist and a schoolteacher. She graduated from James Monroe High School in 1960, and earned her A.B. in Zoology from the University of Wisconsin, Madison, WI in 1964. She then enrolled as a graduate student in the Department of Molecular Biology, University of California, Berkeley (UCB). It was a tumultuous time, because the student protest known as the Free Speech Movement took place in that academic year (1964–65), and Martin along with her fellow graduate students spent many hours in political discussion and activity. Martin did her doctoral work in Harry Rubin's laboratory, where she pursued several projects aimed at elucidating the mechanisms that control the growth of fibroblasts in vitro. She completed her Ph.D. thesis in 1971. It was during that time that she married Steven Martin, a British scientist who had come to Berkeley to do postdoctoral work in the Rubin laboratory.

Academic career
After completing her graduate studies, Martin and her husband moved to London. In 1973, she worked with Martin J. Evans at University College London. Evans was then working with teratocarcinomas (a type of tumor), which are of interest because they contain pluripotent stem cells (known as embryonal carcinoma, [EC] cells) from which all the differentiated cell types in the tumor arise. During the two years she spent working in Evans' laboratory, Martin devised a protocol for isolating and maintaining EC cells in the undifferentiated state and for differentiating them in vitro. This work  laid the groundwork for the future isolation of pluripotent stem cells from normal mouse and human embryos. In 1976, Martin and her husband returned to Berkeley, where he took up a faculty position at UCB and she began a year of postdoctoral work with Charles J. Epstein in the Department of Pediatrics at UCSF. During this period she and her colleagues demonstrated that female EC cells had two active X chromosomes and could be used to study X-chromosome inactivation in vitro.

In 1976 Martin joined the UCSF faculty and established her own laboratory, which was active until 2012. Her first major accomplishment was the isolation of pluripotent stem cells from normal mouse blastocysts. This was also achieved by Evans and Kaufman   in the same year. Subsequently, using sophisticated genetic methods that she helped to pioneer, Martin and her colleagues demonstrated the importance of FGF signaling in the development of many organs including the limb. Martin's laboratory also took the lead in studying the role of negative feedback mechanisms for regulating FGF signaling in the mammalian embryo These studies have led to an appreciation of the exquisite sensitivity of developmental and cell biological processes to even small changes in the level of FGF signaling.

During her tenure at UCSF, Martin served as director of the Graduate Program in Developmental Biology (1986-2009). She also was responsible, in collaboration with a software engineer, Jonathan Scoles, for the development of a database that provides a description of all the genetically altered mice housed at UCSF. This online resource helps researchers determine if mice carrying a particular genetic alteration are available at UCSF and to find out whom to contact about the possibility of obtaining them. Access to this information has saved investigators considerable time and money in acquiring mouse models for their studies and been a stimulus to collaboration between researchers.

Honors
Martin has received numerous awards including an American Cancer Society Faculty Research Award (1979–83), a Guggenheim Fellowship (1991–92), the Edwin Grant Conklin Medal from the Society for Developmental Biology (2002), the  Pearl Meister Greengard Prize (Rockefeller University), co-recipients: Beatrice Mintz and Elizabeth Robertson (2007), and the, FASEB Excellence in Science Award (2011).

She received an honorary Doctorate of Science (DSc [Med]) from University College London (2011). She has delivered numerous special lectures, including the George W. Brumley Jr. Memorial Lecture (Duke University) 2006, the UCSF Faculty Research Lecture (2008), and the Dame Anne McLaren Memorial Lecture (UK National Stem Cell Network), York, England (2011). She served as President of the Society for Developmental Biology (2006-2007), and was elected a fellow of the American Academy of Arts and Sciences (1991)  a member of the US National Academy of Sciences (Section 22, Cell and Developmental Biology) (2002) and a Foreign Member, Royal Society (2015)

Selected publications

Further reading
 Torassa Ulysses, 2001, "Profile: Gail Martin, UCSF scientist opened door; research has been built on her seminal work 20 years ago," at SFGATE, August 10, 2001, see , accessed 26 February 2015.
Stem Cell Research — Potential Solutions, Practical Challenges

References

Members of the United States National Academy of Sciences
University of California, San Francisco faculty
University of California, Berkeley alumni
Living people
Foreign Members of the Royal Society
21st-century American biologists
1944 births
Biologists from New York (state)


National League of Young Liberals (NLYL), often just called the Young Liberals, was the youth wing of the British Liberal Party. It was in existence from 1903 to 1990. Together with the party's student wing, the Union of Liberal Students (ULS), the organisations made up the Young Liberal Movement. In 1988, the ULS merged with the Social Democratic Party's own student wing, and in 1990 the youth and student sections themselves merged to form Liberal Democrat Youth and Students (LDYS). It was renamed Liberal Youth in Spring 2008, and then as Young Liberals in December 2016. The NLYL played a significant role in the development of Liberal thought and action, particularly from the 1960s until the end of the 1980s.

Early years
The NLYL was founded in 1903. By 1906, it had over three hundred branches.

In 1934, the NLYL called for David Lloyd George to lead a Liberal New Deal revival, based on the Yellow Book.

"Red Guard"

One of the significant periods of the Young Liberals was the 1960s and early 1970s. The press coined the phrase the "Red Guard" to illustrate the radical nature of the youth wing. The public became aware of the "Red Guards" at the 1966 Liberal Party Conference in Brighton, when they sponsored an anti-NATO resolution. Over the next decade the YLs were active on a number of foreign policy areas. In particular they were at the forefront of the opposition to Apartheid and the Vietnam war. The YLs took a leading role in the Stop the Seventy Tour of South African Cricket and Rugby teams. Led in particular by an exiled South African Peter Hain (later to become a Labour Party Cabinet Minister), Louis Eaks (later to an editor of Tribune), Hilary Wainwright (future editor of Red Pepper magazine), they took direct action when other Liberals were not doing so.

The party leadership were very unhappy about the antics of their youth wing, and party leader Jeremy Thorpe set up a three-man commission, which produced the Terrell Report. The report accused some of the Young Liberals of being communists. Many Young Liberals described themselves as "libertarian socialists". Peter Hain explained:

"Underlying libertarian socialism is a different and distinct notion of politics which rests on the belief that it is only through interaction with others in political activity and civic action that individuals will fully realise their humanity. Democracy should therefore extend not simply to government but throughout society: in industry, in the neighbourhood or in any arrangement by which people organise their lives."

Thorpe went on to try to stop the election of Peter Hain as chair of the Young Liberals.

At the same time as being active on foreign policy, a group of Young Liberals led by Bernard Greaves, Tony Greaves (later to become a Liberal Democrat peer), Gordon Lishman and David Penhaligon (later to become a Liberal MP) developed the combination of a radical YL approach and involvement in their communities. The Young Liberals put forward an amendment to the party's strategy at the Liberal Party Conference in Eastbourne in 1970 which was passed with little enthusiasm from the Party leadership. The amendment defined the new strategy as:

This was to revolutionise the party, and was known as "community politics". Young Liberals started to show by example how community politics could win elections, first with by-election wins in 1972 (notably with YL vice-chair Graham Tope's win at Sutton and Cheam) and then through the work of Trevor Jones and his colleagues in Liverpool, where they won control of the council. In 1977, there were some 750 Liberal councillors. By 1985, that figure had risen to more than 2,500, and it peaked in the early 1990s at more than 5,000. However, it was only with the election of Paddy Ashdown in 1988 that community politics was fully embraced by the party leadership.

It was Young Liberal chairman Ruth Addison who led the revolt against David Steel's call in 1974 for a government of national unity.

As a result, the NLYL grew stronger, attracting groups to affiliate from surprising areas like rural Wiltshire. Patrick Coleman went on to be a county councillor. However, it also eventually led some to reject the merger of the Liberal Party with the SDP in 1988–1989 to form the Liberal Democrats. Some walked away into political limbo, some joined Michael Meadowcroft in a breakaway Liberal Party, but they had no parliamentary representation. Meadowcroft joined the Liberal Democrats in September 2007.

"Green Guard"

In 1979, the Liberal Party adopted a "no growth" economic policy and became a magnet for young people interested in green politics. Initially led by Felix Dodds, the Young Liberals again challenged the party on a number of fronts. On foreign policy, they not only continued the tradition of the "Red Guard" in opposing the US escalation of nuclear tension, the introduction of Star Wars and the UK's independent nuclear deterrent, and continued to campaign against apartheid, but also started to green the party through both local activities and national campaigns on acid rain, nuclear power and green economics. Michael Harskin, one of the Green Guard, crafted the NLYL manifesto and the attack on the Liberal-SDP Alliance manifesto for the 1983 election. He said:

The party leadership were not happy, and when a delegation of Young Liberals met Gerry Adams to ask him to take his seat in parliament, party leader David Steel attacked them for bringing the party into disrepute. The Young Liberals went on to persuade the party to support the withdrawal of all British troops from Northern Ireland as a long-term aim.

The Young Liberals played a significant role in persuading Des Wilson, the then outgoing President of Friends of the Earth International, to become active again in the Liberal Party. Wilson went on to become party president in 1986. In an echo of the "Red Guard" era, the party leadership under David Steel campaigned to stop the election of Felix Dodds to the position of National Chair of the Young Liberals in 1984. Although not elected that year, he was elected the following year and played a significant role, as did the Young Liberals as whole, in helping to organise the rebellion for the 1986 Eastbourne Defence Debate.

The most significant impact of this period was perhaps the rebellion the Young Liberals helped to facilitate against the SDP-Liberal Alliance leadership of David Steel and David Owen over the issue of an independent nuclear deterrent. The rebel coalition, which included three MPs - Simon Hughes, Archie Kirkwood and Michael Meadowcroft - produced the publication Across the Divide: Liberal Values on Defence and Disarmament, which outlined the Liberal Party's historic opposition to the UK having an independent nuclear deterrent. This resulted in a major defeat to the leadership in 1986, by twenty-three votes (652 votes to 625) at the Liberal Party Conference defence debate in Eastbourne. Many believe that the speech by Simon Hughes won the day for the rebels:

In his final speech as chair of the Young Liberals, Dodds called for "a rainbow alliance on the left in British politics". In 1988, he and other Young Liberals formed an informal alliance with leading Green Party members Tim Cooper, Jean Lambert and Liz Crosbie called Green Voice. This alliance investigated how they might be better relations and campaigns joining together members of both parties. The two Green Voice Conferences in 1988 played a key role in enabling leading MPs Simon Hughes and Michael Meadowcroft to outline to the new Social and Liberal Democratic Party the kind of green agenda that the new party should adopt. Hughes, at the press conference for the first Green Voice Conference, announced that he would not join the new Social and Liberal Democrats Party unless it was to accept a strong green agenda. In 2018, Felix Dodds published his autobiography about the Green Guards, Power to the People: Confessions of a Young Liberal Activist 1975-1987.

Some of those associated with the Green Guard, including Martin Horwood and Adrian Sanders, have gone on to become MPs, and others, including Edward Lucas, Felix Dodds and Stephen Grey, have become journalists and authors on international issues. Others have been active in the Liberal Democrat party communications department, and at 10 Downing Street (during the Coalition government) such as Olly Grender and Carina Trimingham (Chris Huhne's press and media agent). Others chose to take green politics to a local level and lead by example, such as Mike Cooper, who became Leader of Sutton Borough Council, and Louise Bloom, a member of the London Assembly.

List of chairs of the National League of Young Liberals

List of presidents

1906–190? Lewis Harcourt
190?–1908 Franklin Thomasson
1908-1909 David Lloyd George
1909–1926 Walter Runciman
1926–1927 Sir Harry Verney
1927–1932 Frank Kingsley Griffith
1932–1938 Elliott Dodds
1938-1939 Vernon Baxter
1939-194? Frances Josephy
1946–1948 Emrys Roberts
1948–1949 Douglas Eugene Moore
1953–1954 Viscount Samuel
1954–1955 Philip Fothergill
1959–1961 Ludovic Kennedy
1976-1977 Peter Hain
1979–1980 David Alton
1984–1985 Des Wilson
1985-1986 Hunter S. Thompson
1986–1988 Simon Hughes

Prominent former Young Liberals
Michael Foot, Leader of the Labour Party, 1980–1983
Sir Lawrence Freedman, Professor of War Studies at King's College London
Stephen Grey, journalist, author of Ghost Plane: The True Story of the CIA Torture Program
Peter Hain, Labour Cabinet Minister, 2002–2008
Megan Lloyd George, the first female Member of Parliament for a Welsh constituency and Deputy Leader of the Liberal Party. She later became a Labour MP.
Harold Wilson, Leader of the Labour Party, 1963–1976 and Prime Minister of the United Kingdom, 1964–1970 and 1974–1976
Elliott Dodds, Chairman of the Unservile State Group
Felix Dodds, author of 17 books on sustainable development and Chair of the United Nations Conference (2011) Sustainable Societies - Responsible Citizens. In 2018, he published his autobiography Power to the People: Confessions of a Young Liberal Activists (1975-1987).

References

External links
Liberal Youth website
Liberal Democrat website
Liberal Democrat History Group, For the study of Liberal Democrat, SDP and Liberal history

Sources
 Dodds, E., (1919) Is Liberalism Dead?
 Dodds, E., (1922) Liberalism in Action
 Dodds, E., (1926) The Social Gospel of Liberalism
 Dodds, E., (1947) The Defence of Man
 Dodds, F., (Ed.) (1984) Six Essays in Search of an Identity, NLYL, London
 Dodds, F., MP Hughes, S. MP Kirkwood, A., MP Meadowcroft, M.,et al. (1986), Across the Divide: Liberal Values on Defence and Disarmament Hebden Bridge
 Dodds, F., (Ed.),(1988) Into the 21st Century - An Agenda for Political Realignment, London: Green Print
 Dodds, F. (2018) Power to the People: Confessions of a Young Liberal Activists 1975-1988, Apex, New World Frontiers
 Eaks, L. (1988) From El Salvador to the Libyan Jamahiriya: A Radical Review of American Foreign Policy under the Reagan Administration, London: Third World Reports
 Greaves, F., B.,(1971), Scarborough Perspective NLYL, London
 Hain, P., (1971)Don't Play with Apartheid: Background to the Stop the Seventy Tour Campaign, Allen & U
 Hain, P., (1973) Radical Liberalism and Youth Politics  Liberal Publications Department
 Hain, P., (1975)Radical Regeneration  Quartet Books
 Hain, P., (1976) Mistaken Identity: The Wrong Face of the Law Quartet Books
 Hain, P., (Ed.) (1976) Community Politics Calder Publications Ltd
 Hain, P., Hebditch, S., (1978) Radicals and Socialism Institute for Workers' Control
 Hain, P. (2010) Mandela, Spruce, London
 Hain, P. (2015) The Hain Diaries, Biteback Publishing, London
 Pitchford, R., and Greaves, T., (1989) Merger: The Inside Story Liberal Renewal

Youth wings of political parties in the United Kingdom
Political parties established in 1903
Liberal Party (UK)
Youth wings of liberal parties


Akademia Futsal Club are a Polish futsal club based in Pniewy.

Squad

Goalkeepers

Other Players

Honours
1 Futsal Cup of Polonia: 2009

External links
Official Website

Futsal clubs in Poland
Szamotuły County
Sport in Greater Poland Voivodeship
Futsal clubs established in 1999
1999 establishments in Poland


Alberts Šeibelis (26 December 1906 – 12 April 1972) was a Latvian footballer, one of the most popular Latvian footballers in the era before World War II. In 54 matches for Latvia he scored 14 goals

Biography
Šeibelis was born in the provincial town Sabile. In 1922 he joined the newly founded Rīgas FK which later became the dominant Latvian football club of the 1920s-30s. In RFK Šeibelis for a long time had to play with the reserves squad, however in 1925 he made his debut with the Latvia national football team which was looking to include more young players. In his first years Šeibelis more played as a forward but later he became a central midfielder. He organized both the defense and attack, and also scored goals. He was considered one of the best footballers of the Baltic States for several years. In 1928 Šeibelis was on the Latvian team which won the first Baltic Cup, in the decisive match against Estonia he organized the winning goal and was injured by a frustrated Estonian forward who could not go past Šeibelis. In 1936 when Latvia won another Baltic Cup scored a winning goal against Lithuania in the last minute.

In his club career in 1931 Šeibelis left Rīgas FK and joined V.Ķuzes FK and Rīgas Vilki (he played with both clubs at the same time for several seasons). In 1938 Šeibelis with Rīgas Vilki won the Latvian Cup - a huge success for the club which was not among the elite of Latvian football. In 1939 he played his last international match for Latvia as it lost 3–0 to Bulgaria.

After the Second World War Šeibelis lived in the United States, coached a football club in Minneapolis.

Honours
 Champion of Latvia: 1925, 1926, 1930
 Latvian Cup: 1938

References

1906 births
1972 deaths
People from Sabile
Latvian men's footballers
Men's association football midfielders
Men's association football forwards
Latvia men's international footballers
Latvian football managers


Øystein Kristiansen (born 29 April 1975) is a Norwegian orienteering competitor and World champion. He won a gold medal both in the 2004 and the 2005 World Orienteering Championships with the Norwegian Relay team. He received an individual bronze medal in the middle distance at the 2003 World Orienteering Championships.

References

External links

1975 births
Living people
Norwegian orienteers
Male orienteers
Foot orienteers
World Orienteering Championships medalists
20th-century Norwegian people
21st-century Norwegian people


Royal Air Force Troödos, commonly known as RAF Troödos, is a Royal Air Force station in the Republic of Cyprus.

RAF Troödos is a remote Signals Station run by personnel from Golf Section, Joint Service Signal Unit (Cyprus), and also contains Mount Olympus Radar Station. The station is based deep within the Troödos Mountains, approximately  north of Episkopi.

History
Troödos Station is the oldest remaining British military base in Cyprus, dating from 1878. Initially it was used as a cool summer field hospital for troops from the Egyptian Campaign. British Army and Government officials also used it as a summer retreat.

Current use
Declassified documents show that RAF Troödos intercepted satellite communications for the Government Communications Headquarters (GCHQ), and documents released by Edward Snowden suggest this has continued in recent years funded by the U.S. National Security Agency. Information from Snowden also indicates the site acts as a listening post for radio signals from the near Middle East.

The British National Space Centre Starbrook wide-field telescope has been here since 2006. It can detect orbiting objects from  in size.

See also

 Ayios Nikolaos Station
 List of Royal Air Force stations

References

External links

Royal Air Force stations in Cyprus
UKUSA listening stations