# ZL2AFP WSQCall

## Guided Tour

V1.20, 24.03.2018

> ZL2AFP software is well known for simplicity of use and clarity of presentation, and WSQCall V1.20 is no exception to this. The program has been thoroughly tested by a team of intrepid enthusiasts, mostly on the 630 metre band, over 10km to 3000km paths. Daytime QSOs (ground wave) are routine over 300 km!

> In the default mode of the program, the Selective Calling or 'CALL' mode is used. Specific selective calling use is described separately in WSQCALL Help. Selective Calling mode can be turned off, typically to speed up conversation between friends, but after the QSO, the users should return to CALL mode. While it is faster to operate with Selective Calling off, none of these transmissions are logged, no callsigns are sent, and no automated functions are available.

> Screenshot of the ZL2AFP WSQCAL V1.20 software showing real 630 m traffic.
> (Click on image for a bigger view)
> - A description of the various display panes and controls follows further down the page.

> Start the program, using the shortcut you made (instructions in the readme.txt document), and after checking the PTT/CAT dialog, you will be able to see each of the features described here. At the very top, under the banner, is a comprehensive menu system. It provides the various controls and setup options. Here is a complete and detailed description of each Menu item, display and control function.

## Menu System

File

> File/Open Heard station log
> Lets you view a list of the stations heard, in chronological order. This is the file Heardlog.txt. The file lists callsign, date, time and SNR. It is in the form of a CSV file, so you can open it as a spreadsheet if you wish (it is kept in the WSQCall working folder). Logging only occurs while operating in CALL mode (i.e. with Selective Calling ON). This file is also used by the ZL1BPU WSQplot accessory program.

> You can archive the Heard Log by changing its name (you can do this with the program running). The program will then start a new log called Heardlog.txt when required. This function (log keeping) is only relevant to CALL mode.

> File/Open Message log
> Lets you view a list of all transmission heard, in chronological order. This is the file Messagelog.txt. The file lists callsign, date, time, SNR, the message direction and the complete message payload. It is in the form of a CSV file, so\ you can open it as a spreadsheet if you wish (it is kept in the WSQCall working folder). Logging only occurs while operating in CALL mode (i.e. with Selective Calling ON).

> File/Open Locator log
> Shows a list of all special locator messages logged. Entries will have a verified source call sign, date, time, SNR and verified Locator group (Locator, power level in dBm, example RF72is30). No file exists if no valid locator messages have been seen. Logging only occurs while operating in CALL mode (i.e. with Selective Calling ON).

> File/Clear and archive Heard station log
> Renames the Heardlog.txt file, effectively removing it. The old file is renamed Heardlog_yyyy_mm_dd_hh_mm.txt. Helper programs that depend on Heardlog.txt (such as WSQPlot) should not be run until there are new entries in the log, i.e. when a new file has been made and the first station has been logged.

> File/Clear and archive Message log
> Renames the Messagelog.txt file, effectively removing it. The old file is renamed Messagelog_yyyy_mm_dd_hh_mm.txt.

> File/Clear and archive Locator log
> Renames the Locatorlog.txt file, effectively removing it. The old file is renamed Locatorlog_yyyy_mm_dd_hh_mm.txt.

> File/File to send
> Allows you to open a short text file to be sent. When you do so, the whole contents of the file is placed in the transmit buffer. Only part of it will be visible in the TX pane. Given the speed of transmission, you should limit the file size to about 30 words (200 bytes), which will take about five minutes to send. You may ONLY send standard ASCII text files. You should not attempt to send extended ASCII files, word-processor files or any other file types.

> Once the file is loaded, press ENTER or the TX button to transmit the file. You can stop (abort) file transmission using the Esc key or by pressing the RX button. Clear the TX buffer by right-clicking in it, choosing 'Select All' then pressing the Delete key. Files from anywhere on your computer or network can be sent, so be circumspect about what you send to the world!

> There is no automated file save mechanism, so the recipient wishing to save your file will need to copy and paste to a file from the RX pane.

> The file name will be prepended to the text in the buffer, and you can edit this if necessary. Press Enter when ready to send.

> > Note: The file size restriction is for practical reasons, as there is no technical restriction. It will take 15 minutes to send just 100 words.

> File/Launch WSQPlot
> WSQPlot is a third-party program written by ZL1BPU, which makes use of the Heard Log to plot station activity and SNR on a 24-hour basis. It can be launched from here. The program and its setup file WSQPlot.set must reside in the WSQCall working folder. WSQPlot should not be run if there are no entries in the log, as this will generate an error. You can normally leave it running, and it will show all the past activity on the working channel. It shows a graph of signal reports (SNR) versus time for up to six selected stations.

> WSQplot is supplied and installed with WSQCall, but you will need to edit its setup file. It comes with its own Help file.

Settings

> Settings/Callsign
> Sets the user callsign which prefaces each transmission in CALL mode. It is also the callsign which is used to filter incoming messages in CALL mode.

> This callsign is free-form, so could be shortened to 'Ted' or 'Joe' if you wish, and it can be a mix of upper and lower case. If the callsign used is not your licenced callsign, you will need to manually append the callsign to transmissions every now and again in the usual manner. ID requirements vary according to jurisdiction. Be aware that some countries do not accept in-mode digital ID, so you may need to add periodic voice or Morse ID. The program does not offer Morse ID.

> Preferably, the callsign used and stored here will be in lower case. Not only is this simpler for other users addressing you to type, and faster to transmit, but lower case text has a lower error rate than upper case.

> > Note: Callsign extensions (such as g0pfg/3, w1aw-4 or zl1ee_g) are permitted.

> Settings/Location (QTH)
> Allows you to set your location sentence. This is free-form text, and could be a GPS position, a geographical location, Maidenhead Locator, street address, or a mixture of all of these. The sentence can only be entered manually (i.e. not directly from a GPS receiver). This sentence forms the reply to the WSQCall callsign@ request.

> Settings/Locator square and radiated power
> This is where you set the sounding propagation message (see next item regarding the PROP option). The Locator must be six letters/numbers in standard Maidenhead format (e.g. RF72is), and the power is (on LF/MF) by convention expressed in dB mW EIRP (example, 100W transmitter, 1% efficient antenna = 1 W EIRP or 30 dBm). For example 'RF72is30'. When the message is transmitted as a sounding, a checksum is appended to ensure accuracy.

> Settings/User message (QTC)
> This is a message that users can read remotely with the WSQCall callsign& request. It is free-form text, preferably a single sentence.

> Settings/Sounding message
> This sets an optional short message that can be appended to a Sounding transmission. Please keep them short! When you change the message, you need to turn SOUND (blue button) off, then on again for the changes to register.

> There is an addition feature offered in preparation for a web-based propagation database. On the Sounding message dialogue, if you check the PROP box, the sounding format will be a standardised one containing locator and transmitted power. See previous item about how to set the message.

Options

> Options/TX inhibit
> Normally in CALL mode, transmissions follow the CSMA rules and will not take place until the squelch has closed, indicating that the channel is free. If the channel is plagued with carrier interference or other noise which elevates the signal level above the squelch setting, no transmission can take place. When this option is disabled, the transmission will not wait until the channel is free. The default is ON, in order to meet the CSMA rules. Please leave it that way unless you are testing something on an unused channel.

> Options/RX only
> When this option is asserted, the transmitter will not reply to incoming commands, and nor can you send from the keyboard. The default is OFF. There are two main uses for this feature: (1) in a multi-operator base station operation (such as an Emergency Headquarters), a dedicated receiving operator can use the same call sign as the transmit operator (and see the same messages) without transmitting and interfering with the transmit operator's receiver. The receiving operator's logs will also log the transmitted messages. (2) This feature is also a useful tool for testing two instances of the program on the same computer.

> Options/Print directed messages only
> The Receive Pane is the larger yellow area at the top of the program window. Efforts have been made to keep the RX Pane tidy, and this is one of the measures taken. With this option on, messages that are not for you will never appear in the RX pane. Junk which results from a false decode will also be suppressed.

> With this option off, messages not intended for you, and any junk text decoded, will appear in the RX pane in green.

> Options/Sounding message ON
> Starts the optional Sounding message that can be appended to a Sounding transmission. When you change the message, you need to turn SOUND (blue button) off, then on again for the changes to register, then select this option. It is not possible to transmit a free-form sounding message as well as the Propagation message, without writing your own 'smart sounding' application. Sounding is not possible when CALL mode is turned off, as no callsign is transmitted.

> When this option is off, only the brief standard Sounding will be sent.

> Options/SOUND interval
> The SOUND function makes periodic brief transmissions in CALL mode. This menu item allows you to select 1, 10 or 30 minute sounding intervals. Under most circumstances you should leave this at the default (30 minute) setting. Sounding allows other stations in CALL mode to build a list of active stations, and record propagation and activity information in a log. All transmissions heard (and verified) are logged.

> If you change the sounding message or the interval, turn sounding off and on again for the changes to register. Activate sounding by pressing the blue SOUND button.

> Options/TX reply retries
> Sets the waiting time for the CSMA (Carrier Sense Multiple Access) protocol, which prevents stations from transmitting over each other, and assigns message priority according to message type. The default value is fine for most applications. Increasing the value may be useful when operating on a noisy or busy channel. This does not affect the turn-around time, only how long the software will hold a pending outgoing message or reply (waiting for a clear channel) before it gives up and abandons the message.

> Options/Peaks "hit parade" count
> Selects at least 3 (default) or 6 FFT cycles over which the real-time decoding algorithm decides whether there's a new symbol. The WSQ mode peak-hits decoder has no sync - 3 is the default value, suitable for most conditions, while 6 may help when it's particularly noisy. You need to experiment to see which best suits the current conditions. This only affects the Monitor text, not the synchronously decoded text.

> Options/Monitor Decoder
> This item relates to the 'peak-hits' decoder method. The default setting is 'Cumulative', meaning that the decoding algorithm bases its result on any viable same FFT detector decisions within the current symbol period. This is generally the most sensitive method and best handles lightning noise. The alternative is 'Sequential', which requires three or six sequential solutions to be the same. This can be better under fading conditions. Experiment to see which best suits the current conditions. It can potentially mean a difference of about 2 dB in sensitivity. It only affects the real-time Monitor text.

Display

> Display/Symbol marker
> This feature 'tags' the received signal symbols on the waterfall with a yellow line as they are detected. This makes seeing the signal easier when it is weak. The default state is ON, and you can select the markers ON or OFF. You may not see the markers when the signal is strong or the Brightness is high. The setting has no effect on reception.

> Display/Waterfall speed
> Allows a choice of waterfall speed; fast or slow (default). More processor power is used by the receiver when this is at the Fast setting.

> Display/Waterfall colour
> Obvious! Cool blue (default) or bilious green waterfall display.

> Display/Spectrum/Oscilloscope display
> Here you can choose an overlaid real-time display of the audio Log spectrum, audio Linear spectrum or an Oscilloscope (sound card voltage) display. The display is overlaid on the waterfall. The default display is the Linear spectrum. You can also turn this display Off.

> The Linear display is useful for adjusting the Noise Blanker. The Oscilloscope can be used to adjust the input audio level.

> Display/S-meter
> This entry brings up a small S-meter display (see below), which includes a real-time bar-graph, a text indication, and a moving S-meter history graph. The S-meter will stay on top of other windows.

> The S-meter display

> The S-meter is sensitive to both signal level and background noise, and reads continuously while on receive. The S-meter will only display correctly if the Input Gain (Menu Radio/Input gain) is correctly calibrated at S9 with an S9 signal. The receiver should be operated with AGC OFF.

> > Note: The S-meter is not the same thing as the SNR reading (the bar graph on the main display), which indicates only Signal to Noise Ratio. They are inter-related but independent. The S-meter is affected by receiver gain and AGC, but not by the software AGC.

> Display/Text colour
> ON means that in the RX pane, received text is green, Selective Calling received text is blue, TX text is red, and timestamps are grey. Off means all text in the RX pane is black.

> In the TX pane, text is always dark blue.

> Monitor pane text is always black, while timestamps are grey.

> Display/10 minute timestamp
> This feature is useful if you want to know when someone called or when some test stopped working, or propagation is lost. It puts a timestamp in the Receive pane and the Monitor pane, every 10 minutes. If reception is happening at the time, it may appear in the middle of the text. If this feature annoys you, turn it off and check for transmission times in the log (Menu File/Open Heard station Log).

Radio

> Radio/Audio devices
> Allows you to set the audio resources (source, destination, levels) used for recording (RX) and playback (TX). If you change the audio source here, it is best to close the program and restart afterwards, as the program may not notice the change in the operating system.

> To adjust your actual transmit power, use the little applet which pops up when you click on the speaker symbol on the Tool bar. You may need to enable this from the Windows Control Panel. Alternatively, use Soundcard/Audio devices, select the Playback tab, select the device you intend to use, click on Properties, select the Levels tab, and adjust the Speakers slider to set the level.

> Radio/Select soundcard
> Allows you to select which sound card is used for reception and transmission. You can change this OK while the program is running. These settings are remembered for the next session.

> > Note: If you change the sound device configuration (especially if using a rig with internal sound device, or using a USB sound device), you may find that when you start WSQCall it may not find the device. The solution is to close WSQCall, delete the WSQCALvnnn_setup.txt setup file, and restart. Then reselect the appropriate sound device.

> Radio/PTT/CAT
> This dialog box sets the COM port used for PTT commands using the RTS and DTR lines, and also for CAT commands. The default value is that set in the WSQCALvnnn_setup.txt file. This dialog allows you to change port and control method.

> For CAT operation, set the COM port to be used here, and select the appropriate transceiver definition. This software supports only a limited range of transceivers directly. If you have a newer unlisted rig with CAT, follow the instructions listed under "Installation" towards the bottom of the Main Help page.

> Because the same COM port is used for hardware PTT and CAT, when you select CAT, the hardware PTT (RTS and DTR) continues to operate, but will (probably) be ignored by your transceiver.

> Radio/Input gain
> This item brings up a control with which you can adjust the incoming audio level from the receiver. The default setting is -40 dB. The control is ahead of the software AGC system, so normally it has no effect. If you turn off the AGC, you can control the signal level with this control (adjust by watching the waterfall). This can be tricky to do. If you have trouble, just leave AGC on, and adjust this control so the background noise level reads about S2 - S3 on the S-Meter (Menu/Display/S-meter).

> This control is primarily used to adjust the calibration of the Signal Strength Meter (S-Meter) and S-Meter reporting in the Heard Log. It has no effect on the SNR measurement or indication, provided AGC is on.

> Radio/Squelch speed
> This item brings up a pair of controls used to adjust the behaviour of the Signal to Noise Ratio (SNR) measurement. They don't affect the actual measurement, just how fast the measurement tracks the signal. The default attack time (on a new signal) is medium, and the default Decay time is fast. Under most conditions a medium Decay time would be best, and try Slow for fading conditions.

> The purpose of these controls is to best adjust the start and stop response times (the Squelch) of the Synchronous Decoder, which is sensitive to fades, but they also affect the 'peak hits' decoder used by the Monitor.

> - Setting the Attack time too fast can cause excessive junk text on noise bursts. Too slow and the Squelch may not open in time to catch the incoming callsign.

> - The Decay time can affect how quickly your station can respond if the other station fades out at the end of transmission, or stops abruptly. Most transmissions end with a special 'End of Transmission' sequence, which bypasses this slow Decay, allowing slick operation. The slow Decay time allows the Synchronous Decoder to continue through fades without resetting.

> Radio/AGC
> Allows the automatic AGC in the receiving software to operate in an Off, Fast or Slow manner. 'Fast' should be better if there is fast fading. 'Fast' is the default mode, as this best suits rejection of lightning pulses. The AGC affects the brightness of the waterfall display (keeps it constant), and also enhances the reception process. 'Off' may be useful when there's ignition or other repetitive pulse noise.

> > Note: If you can, it is best to operate your transceiver with its AGC OFF or at least FAST, so that lightning pulses don't disable the receiver any longer than necessary. Don't worry - the software will reject the QRN.

> > Note: The S-meter provided by WSQCall will under-read on medium and strong signals if the receiver AGC remains ON. No other operation will be affected.The WSQCall software AGC does not affect the S Meter readings.

Speed

> Selects transmit symbol rate. There are four options, as shown in the table below. The default is modest (0.5 baud), and under most circumstances this should be reliable. It achieves about 5.5 WPM. The slower speed (0.25 baud) will be more reliable under poor conditions. When signals are strong, try 1 baud.

> The lower speeds are also more sensitive and handle static interference much better. You can use 'Options/Peaks "hit parade" count/At least 6' to advantage at 0.25 baud. The typing speeds (WPM) in all modes are about 10x the symbol rate (baud).

> Mode | Baud | Bandwidth | Typing Speed WPM | Sensitivity ~ SNR | ITU Definition
> --- | --- | --- | --- | --- | ---
> WSQCall 1.0 | 0.976 | 100 Hz | 15.4/11 | -24 dB | 100H4F1B
> WSQCall 0.51 | 0.488 | 50 Hz | 7.7/5.5 | -27 dB | 50H4F1B
> WSQCall 0.25 | 0.244 | 25 Hz | 3.8/2.5 | -30 dB | 25H4F1B
> WSQ22 | 0.488 | 64.4Hz | 7.7/5.5 | -27 dB | 64H4F1B

> Basic details of the WSQ modes.
> 1 Default mode. 2 WSQ2 mode is compatible with previous WSQ2 versions

> By the way, the tone spacing changes with the mode, which allows you to easily see if you have the wrong mode selected for an incoming signal. The default 0.5 baud mode is about 50 Hz wide, and will nicely fit between AC supply QRM lines. Sensitivity indicated is only a guide, and can be reduced by static interference. Two typing speeds quoted: they are for optimum lower case 'CW speak' and full upper & lower case random text.

> > Note: The Speed setting in WSQCall V1.20 MUST be matched by the speed setting at the receiving station, because both the width of the signal and the synchronous decoder rate are mode specific. This is different to FSQCall V1.00.

> In WSQCall you can't change the other station's transmit speed remotely.

Help

> Help/WSQ Introduction
> Help/Guided Tour
> Help/WSQCall Selcall
> Help/Syntax
> Help/Rules

> These menu items bring up a comprehensive set of Help files, using your default browser. Please read these carefully, as they answer just about every question you may have about WSQCall operation.

> Help/About...
> Displays information about the program, such as author, release date and version.

## Text Panes

> Receive Pane
> Directly below the menu is a large yellow area - this is the Received Text Pane, which receives output only from the Synchronous Decoder. When not in CALL mode (the blue CALL button/light is dark), all received text, no matter whether directed to you or not, is displayed in green, and transmitted text in red. WSQCall has squelch based on signal-to-noise ratio, in order to remove most junk between transmissions.

> Messages appear here only after the squelch has closed. Text not for you can be suppressed with the 'Options/Print directed messages only' option, which is on by default.

> In the default CALL mode (the blue CALL button/light is on), received text directed to your station is displayed here in blue, while transmitted text is again shown in red. In CALL mode the squelch has a 'Smart' feature which manages squelch delay to cope with fades during transmission, but closes quickly when the end of transmission is detected from a specially transmitted 'EOT' marker. No rubbish should appear in this pane in CALL mode.

> Messages not intended for your station, have syntax errors, or where the source call sign and CRC don't match, do not appear in the Receive pane. If you select 'Options/Print directed messages only' off, they will appear, in green.

> > Note: If 'Options/Print directed messages only' is enabled, and CALL mode is OFF, or is OFF at the other station, no received text will appear at all!

> You can also cut and paste text from this pane, and it has a right-click menu for this purpose.

> > Hint: You can change the size of the text in this pane by selecting all of it, then pressing CTRL+SHIFT+"<" or ">". If you want ongoing text to be in the new size, make sure you include the very last character in the selection.

> > Note: You MUST press PAUSE before attempting to select and copy from the Receive Pane, or change the text size.

> Transmit Pane
> This is a small pink area below the Receive pane, on the left. This is where you type what you want to transmit: callsigns, commands and text. While the transmitter is not running, you can also type ahead, and correct what you type with normal Windows editing functions. The slider on the right becomes active when there is more text in the transmit buffer than will fit on the screen. Being verbose is not encouraged, however, especially at slower speeds.

> It is unwise to try typing while a sentence is being transmitted. This can cause confusion and missed text, and also messes up the end of the sentence EOT marker which allows the squelch at the receiver to shut quickly and cleanly. You cannot edit or insert text while transmitting.

> In CALL mode, once you start typing in the TX buffer, the program will ignore incoming commands which require a response. This restriction is removed once the TX buffer is cleared. If you are expecting incoming commands, make sure your buffer is cleared. You can select all the text in the TX buffer, then press Delete (or mouse right-click and select Delete) to clear the TX buffer. You can call up call signs to direct your messages to, by clicking on the call in the Heard List (described below).

> Monitor Pane
> This is a larger pale yellow area below the Receive pane, on the right. In both CALL and non-directed modes, all incoming sentences, whether directed to you or not, are displayed here. The Monitor Pane displays only text from the real-time 'peak-hits' decoder, which may contain more errors or disjointed text. It could also be followed by some junk characters.

> This is the 'engineering' area. Messages appear here in real time, one character at a time.

> This is a good place to monitor other traffic, read messages not intended for you, or that are not recognised due to errors, and to read messages that are incorrectly directed or formatted. If there is a fade during reception, the Receive Pane may display part of the sentence prematurely, and miss the rest, but you will be able to see any remaining text after the fade here in the Monitor. The Monitor is also very tolerant of incorrect sending speed or sound card timing errors.

### Other Information and Controls

> Heard List
> There is a small white area to the right of the main Receive Pane. In this area you will find listed 'allcall', followed by the callsigns of all incoming (heard and verified) stations, whether sending text or simply Sounding. You can select stations in this list to be the default destination callsign for your Directed transmissions by left-clicking on one of them. You can also select a command to follow the Direction by right-clicking anywhere in this area.

> The last callsign you clicked on is remembered, so next time, to start a sentence directed to the same station, just press F1 to bring the callsign up again.

> The Heard List is chronological in order, and is cleared when you close the program. It has no connection to the Heard Log, which is saved as a file, complete with time stamps and signal readings. You can access this from the menu, File/Open Heard station log.

> Waterfall Display
> Below the TX buffer is the received audio waterfall display, which has frequency calibration below, and spans from about 1450 to 1600 Hz (less range in 0.25 baud mode, more in 1 baud mode). It shows the received signals over time, as the waterfall moves down, with older signals toward the bottom. The waterfall moves quite quickly, so individual tones can be seen. When the 'tagging' option is on, each recognised symbol is tagged here with a thin yellow line.

> The waterfall and controls area

> Two full-height vertical yellow lines indicate the signal-focussed area of the decoding software - the received signals must be completely contained between these marks or copy will deteriorate markedly. Ideally the received signal will extend upwards from 1500 Hz, the amount depending on the mode. These yellow markers (and the signal-focussed frequency range) can be adjusted with the mouse. Hover the mouse over one of the lines (during receive), and they will both brighten. Click on the line and slide the mouse to move the upper or lower limit. The narrower you make the received frequency band, the better the rejection of noise, but if you make it too narrow, you risk losing some of the signal, and it will also affect reception of drifting or off-frequency stations.

> This feature is intended to allow reception of off-frequency stations. It can also be used to eliminate carrier interference just outside the range of incoming signals. Carrier interference within the signal-focussed range will severely affect reception if it is stronger than the signal. Moving the yellow markers has no effect on the transmitted frequencies.

> Usually operation is channelised in 100 Hz steps, but if a station is off frequency, tune carefully to the signal. You should slowly tune the receiver so the whole of any incoming signal is between the yellow lines. As the signal steps back and forth quite a bit due to the way signalling occurs, you will need to watch it for a while to ensure it is all contained within the yellow lines. The lowest tone of any transmission is the reference frequency. This will be Dial Frequency + 1500Hz on an SSB transceiver in USB mode. All other tones are higher than this, by up to 50Hz. Tuning is so easy that with a modern transceiver you just set the dial to the net frequency, or a round 100 Hz step frequency, and forget about it. RIT is not necessary as the transmit and receive frequencies usually the same. Slight errors can be corrected by moving the yellow markers.

> > Note: Tuning needs to be within about ± 20 Hz: if ANY tones fall outside the yellow lines, copy will deteriorate quite quickly. It is not really practical to operate WSQ in a net situation with an older (less stable) VFO-tuned rig and transverter. The stability and accuracy of the transmitter and receiver should ideally be better than 1 ppm (1e-6).

> Since WSQCall operation is generally 'channelized', there is never a need to tune in signals anyway. Just set the transceiver or transmitter and receiver to the known channel or calling frequency. The automated response features of WSQCall rely on every station operating accurately on the calling frequency.

> Spectrum/Oscilloscope Display
> This interesting feature offers an optional real-time signal display, overlaid on the waterfall. The display is shown in light grey, and has four modes:

> 1. Display Off.
> 2. Log spectrum - shows the incoming sound card audio spectrum, depicted in a linear manner.
> 3. Linear spectrum - shows the sound card audio spectrum, depicted in a logarithmic manner.
> 4. Oscilloscope - shows the actual sound card audio voltage.
> The horizontal axis of the spectrum displays is frequency, matching the waterfall. The horizontal axis of the oscilloscope is time. These displays can help with setting the Notch depth and the Noise Blanker level.

> The linear spectrum overlay

> Signal Meter
> To the left of the waterfall display is the Signal to Noise Ratio (SNR) meter, which has been calibrated against a simulator to indicate real signal to noise ratios in a 3 kHz bandwidth, using a green bar. There is a thin yellow line across the meter, which indicates the level below which Squelch will close (printing stops). Left click here to change the Squelch level. The optimum setting for Squelch varies somewhat with band conditions, but -28 dB would be a place to start. It should be set about 1 dB to 2 dB higher than the Signal Meter green bar with no signal coming in.

> When the received signal End Of Transmission (EOT) marker is received, the yellow Squelch level indicator will briefly turn red, and the SNR level will fade quickly. If the EOT marker is missed, the SNR reading will decay slowly, which affects when the Squelch will close. Slow decay allows the decoder to handle deep fades without stopping prematurely.

> The meter has averaging to remove the effect of impulse noise, and has different user-settable time constants for Attack and Decay. The peak value reading is the true signal SNR estimated in a 3 kHz bandwidth. The reading is likely to be over-optimistic if a narrow receiver filter is used (less than a 2.4 kHz SSB filter), and this also affects the squelch setting.

> There is generally no advantage in using a receiver filter narrower than the usual SSB filter, as the software is only looking at signals between the yellow lines (about 70 Hz bandwidth). The only reason to use a narrow filter is to prevent interfering carriers outside the signal area from affecting receiver AGC.

> > Note: The transmitter will not operate while the Squelch is open! This helps prevent doubling. If the squelch level is set too low, you may not be able to transmit.

> > Note: If the Squelch is set too high you may miss some incoming text. When working weak stations, better to set the Squelch lower, and have a few spurious characters in the Monitor between overs, than lose valuable text.

> Synchronous Decoder Displays
> Below the waterfall, to the right of the Bright control are two small 'oscilloscope' displays. The one on the left is a 'Correlogram', which indicates the relevance of the 16 cross-corellator cells once the sentence has been received. This indicates by its biggest peak where most of the individual symbol tone changes occurred during reception, in other words where the signal sync is. This appears after the squelch has closed and the stored samples have been analysed.

> Corellogram Display (shown twice size)

> The right-hand 'oscilloscope' display is a sync history display, and shows where the symbol changes were found through the whole transmission. Time is represented vertically (one symbol time) and horizontally (duration of the transmission). This display can be seen working as a signal is received. The random dots at the right end represent noise following the signal before the squelch closes.

> Sync History Display (shown twice size)

> User Controls - Brightness
> Along the bottom of the program window are several button controls and the Bright (Brightness) control. This slider control adjusts waterfall brightness. Keep it to a minimum to avoid waterfall blurring, and even lower to allow the yellow symbol markers to be seen. The setting is remembered for the next session.

> User Controls - Notches
> Under the Monitor Pane are the three Notch controls. Each one can turn on or off an individually controlled notch, used to suppress carrier interference which might disrupt the detector. The button is brightened when the notch is activated.

> The three notches are indicated by a colour-coded pair of lines which indicate the notch width. Each notch can be dragged sideways (click within the notch with the left mouse button) to suppress an unwanted carrier. The notch is turned off by pressing the appropriate button again. By right-clicking on any one of these buttons, you can activate a small box with six sliders, where you can individually adjust the width and depth of each notch! The controls are colour coded the same as the Notch buttons.

> While notches effectively kill carrier interference that can derail reception completely, bear in mind that the more of the active area you notch out, the more real tones you might lose, which can lead to more errors. Don't use any more notch depth that that required to attenuate the interferer sufficiently. Just 6dB is often enough.

> Weak interfering lines can also usually be effectively eliminated using a notch just 6dB deep, which will have minimal effect on real signals.

> User Controls - NB
> Left-click on the button to activate the Noise Blanker. The Noise Blanker is effective on lightning noise (QRN) and some industrial noise, but can be tricky to adjust so that it eliminates the noise and not the signal! Right-click on the button to bring up the Strength control. The higher the slider, the more effect the blanker will have.

> The best way to adjust it is to watch the Linear Spectrum display. If you set the NB too high, the Linear Spectrum display will rise quickly, indicating that the NB is affecting normal background level, and affecting the AGC.

> User Controls - Buttons
> Just to the right of the Notch controls and NB are several blue buttons.

> The CALL button is normally light blue, so selective calling functions operate, and logging is available. Transmissions are made with the appropriate Selcall preamble.

> When CALL mode is disabled (by pressing this button), the button changes to dark blue with a red line and ellipse over it. When CALL is disabled, none of the automatic WSQCall functions are available.

> The SOUND button enables or disables the automatic Sounding feature. When not active, this button is dark blue. When active, transmitting or waiting to transmit, this button is light blue. Sounding parameters can be altered from the Options menu. The Sounding timer starts when you press the button.

> Further to the right are three more buttons. They are the PAUSE button, the Transmit button (TX) and the Receive button (RX). Each of these is dark blue when not active, and bright blue when active. The program starts in Receive. PAUSE is used while editing the screen, as otherwise the cursor will jump around when you least expect it. It also stops reception and transmission until either RX or TX is pushed again. You can also stop transmission instantly with the ESC key.

> Resizing the Window
> You are able to resize the WSQCall program window by dragging the border sideways or downward. The default size will fit on the screen of a Netbook. It is not a good idea to shrink the window size much, as you'll lose some controls.

### Transmitting and Receiving

> Transmit
> When you wish to transmit, simply place the cursor in the pink TX pane and start typing. You should type ahead (i.e. before you start transmitting, typically while the other guy is transmitting). When you've typed your sentence, and the channel is clear, press ENTER or the TX button, and your typed-ahead text will be sent. As you transmit, the characters sent disappear from the TX pane and appear in the RX pane once they have been sent. This will let you see the progress of your transmission.

> In CALL mode, the callsign and checksum preamble will automatically be sent first. In non-directed mode, no callsign preamble will be sent, and no checksum is sent.

> In CALL mode, if you start the transmitter with an empty buffer, it will send your callsign preamble, and then stop. This replicates the Sounding message, and is useful as a 'zl1xyz listening on channel' prompt.

> > Note: If you forget to place the cursor in the TX pane, your typed text might not go anywhere useful!

> > Note: You should only type while receiving. If you continue to type after transmission has started, the transmitter may catch up with you, and if it does, the transmission will stop prematurely. Wait until the program has returned to receive before you type again.

> > Note: In CALL mode, you should definitely not type after transmission has started, as this will disrupt the 'smart squelch' feature and may mean that only the first part of your transmission will be seen on the recipients RX pane.

> > Note: When Tools/RX only is invoked, the TX button does not operate, and pressing ENTER in the keyboard buffer has no effect.

> Receive
> The program starts in the directed message CALL mode (SELCAL on), in the receive state. You can interrupt a transmission and return to receive by pressing the RX button or the Esc key on the keyboard. If you press either while text remains in the TX pane, this will not be sent until you press TX again, and at least one character may be lost. Normally you should complete typing the transmission text with an Enter key, and wait until all the text appears in the receive pane, including the new line caused by the Enter, before typing again. At this point the transmitter will stop automatically. Don't worry, you will quickly master the technique, and it will soon seem obvious.

> Keep a close watch on the waterfall display during reception, and listen carefully before you transmit, to ensure that you don't double with someone else. It can still sometimes happen, even with the 'squelch lockout' feature, and if you sense that it has, immediately press the RX button, or hit the Esc key, so your transmission stops.

> Watch the signal SNR on the meter (bottom left). You will probably find that the signal fades up and down by 10dB or more, and print may stop or become garbled during fades. Reduce the Squelch level if this happens.

> The squelch level is set by clicking in the SNR meter with the mouse. It's better to have a few garbage characters than miss real text. The squelch uses the slow SNR decay to hold up during fades. Keep sentences short, and stick to lower case and CW-speak abbreviations to maximise typing speed.

> Pause
> The PAUSE button stops both transmission and reception.

> It is best not to edit text during transmission, although you can delete typed characters (using Backspace), after and including the error, then retype. The problem is that this simple program does not remember cursor locations, and the transmit and receive panes share the same cursor control. Thus it happens that when you move the cursor manually (click in the text with the mouse), you may find the software promptly moves the cursor back to the end of the typed text. During transmission the program may miss your keyboard strokes, so again, typing while transmitting is not encouraged.

> In WSQCall CALL mode it is bad practice to edit the text (or add further text) while transmitting, as this then messes up the other station's Smart Squelch, since the additional text removes the hidden EOT command character.

> Another problem with editing while transmitting is that the transmission will stop when it catches up with your typing. The only way to reliably edit the transmit buffer text (i.e. edit by moving the cursor insert position) is to do so while receiving.

> > Note: You can copy and paste from the RX pane to the TX pane, so if you have a request to repeat part what you've just sent, simply copy the text from the upper pane and repaste it in the lower pane. The other station could also use the '+' command to cause a repeat the whole transmission.

> Escape
> It's not so convenient to move the mouse to the RX button if you need to stop transmission in a hurry, so the software provides a keyboard 'abort transmission' function via the Esc key, which has the same effect.

> This feature is very useful if you sense, just after starting a transmission, that someone else has just done the same. If you are quick, you won't miss much of their transmission, and you will probably not lose many of your own transmitted characters either, and any that have already gone will be easily replaced by moving the cursor to the start of the TX buffer and typing them again (you don't need to retype the automatic preamble - and you should delete what's left of it before retransmitting).

> Note that the Esc feature has no effect if the transmission was initiated by a 'Helper' program.

Copyright © Murray Greenman and Con Wassilieff 2013-2018. All rights reserved.