Welcome

Welcome to the help system for the CW DecoderXP program. This help program will guide you through to using the menu selections and to using the control buttons.


Introduction

Welcome to the CW DecoderXP program. This software was designed to allow CW operators to see, hear, and display as text CW signals from their receivers. This is accomplished by routing the audio from the receiver output to the audio (MIC In) input of the sound port of the computer. The software runs on Windows95, Windows98, WindowsME, WindowsXP, and Windows2000 operating systems.


Setup

To install the software open the control panel on the computer and run the install/delete software application, then follow the instructions. Be sure to have the install disk in the floppy drive. After the software has been installed go to the Windows START menu:

Connect an audio cable from the receiver audio output to the computer "Mic In" (usually the end connector) port of the computer sound board.

Before running the program be sure that no other program is using the sound board. Also, if if sounds are turned on while performing keyboard or mouse commands, turn this feature off.

1)	Start the CW Decoder program (select CWDecoder2 from the Windows START menu).

2) Tune in a CW signal and then move the frequency slider until it is under the signal on the graphic display.

3) Go to the START menu select on the windows desktop.

4) Select "programs" then "accessories" then "multimedia" then "volume control" or "audio mixer" (depending on the system),

5) Within the audio panel select "Options" then ""Properties" then "Recording",

6) Check the "Microphone" box. This selects the Mic in as the recording source.

7) Select OK.

8) Set the mixer gain up/down for the microphone until the Overload status bar stays GREEN without RED indications. It is important to set this input signal level on the mixer panel correctly. The CW Decoder program will not work as well with strong signals if there is an input signal overdrive.

9) Close the window.


Displays

The CW Decoder program has several display: a graphical Spectrum Display, a Text Display, a Signal Strength Display, a Code Status Bar, an input signal overload indicator, and WPM counters. The spectrum display shows a frequency spectrum of about 20 Hz to 2500 Hz of the audio from the receiver. A slider bar below the display selects the spectral line to be used for text decoding. The text display will show text across the screen when text decoding is selected. There is a text display that depicts the keyboard text that will be transmitted. The code status bar indicates whether text decoding is not active, in the learn mode, or has completed learning the dot/dash lengths. A WPM counter is shown as a listening aid. The peak frequency is active in the SCAN and TEXT modes of operation.


Menu Selections


File


Save Recv

The Save Recv menu selection saves the received decoded text in user selected file.


Save Xmit

The Save Xmit allows the transmit screen text to be saved in a user selected file.


Load Xmit

The Load Xmit menu selection allows a user load the transmit window with text from a user selected file.


Volume Control

Volume Control; This menu selection will bring up the Windows Volume Control/Mixer which will allow you to set the input level to the sound board in the computer. Set the input level up in volume until the "Overload" light starts to blink red and then reduce the volume level to about 1/8 th of the overload level.


Quit

The Quit menu selection will allow the user to unconditionally terminate the program. Clicking the upper right "x" on the application window will also terminate the program.


Quick Instructions and Help


Spectrum Window

The spectrum window displays the received audio spectrum in the frequency domain. Lower frequencies are to the left and upper frequencies are at the right. A vertical red bar indicates the portion of the spectrum that is being decoded. Place the spectrum bar by either using the slider under the spectrum window or clicking on the display to zero in on a signal to be decoded.


Receive Text Window

The received text window (second window from the top) displays the decoded CW text when the operational mode is "Text". It displays typed in text in the manual modes and acts as a scratch pad buffer for the operator. The right scroll bars allow scrolling of text that is not currently being displayed. This window may be saved in a text file.


Transmit Text Window

The transmit text window (3rd from the top) displays the text that is being transmitted. Text may be typed in and saved to one of the ten (10) memory locations, or used as an immediate transmitted text window.


Signal Level

The signal level indicator is located at the lower right portion of the application window. This indicator displays the average signal level being received.


Threshold

The threshold level indicator is next to the signal level indicator at the lower right portion of the application screen. This indicator displays the average threshold being used for signal decoding.


Peak Frequency

The peak frequency status displays the frequency of the loudest signal in the spectrum. It only is active during the SCAN Operational mode.


Rec WPM

The received words per minute (WPM),  is a coarse indication of the received code speed. The code speed is accurate to

within ± 1 wpm.


Xmit WPM

The transmit words per minute (WPM) indicates the transmit speed of the CW generated text.


Receive Gain
Rx Gain

       The receive gain slider adjusts how much the signal is amplified by the software. A good setting is to adjust the gain until the spectral display being selected just reaches the top of the display.

The four radio buttons ( labled 1,2,3, and 4) to the right of the slider determine the coarse scale of the gain.


Xmit Speed

        This control slider sets the transmitted code speed to between 5 wpm and 40 wpm. There is a "Speed" window that displays the setting of the slider.


Xmit Tone

       The side tone frequency (Xmit Tone) slider sets the frequency of the regenerated side tone when the Op mode button COPY has been selected. Depending on the computer system used there may be audio feed-through from the receiver audio at the same time the side-tone is heard. To hear the side tone, the computer sound board must have the MIDI synthesizer capabilities. Most computer sound boards have this capability. Otherwise try to listen to the side tone being received from the transceiver through the speakers of the PC.


Scan

Three buttons control the basic operating modes of the program. The SCAN button allows the program to operate as an audio spectrum analyzer with a graphical spectrum display.


Manual

The MANUAL allows the operator to act as the decoder and type text in a window. The MANUAL button disables the text

 decoding by the program and allows the operator to type in the text in the middle window. This allows the middle window to

act as a scratch pad buffer.


Text Op Mode

The TEXT button allows the program to decode the CW into a text stream. Be sure that the frequency slider is under the signal in the spectrum.


Word Spacing

       This button allows the text decoding software to adjust for code transmissions that have successive words close together.

        In the LONG mode the text decoding the software expects words separated by a longer duration during the transmission. This mode is also more useful for operators who have a swing to their code or have a tendency to have longer dashes than normal.

In the MEDIUM mode the text decoding the software expects words separated by a slightly shorter duration during the transmission.

In the SHORT mode, words are expected to be closer together. This mode works if the operator has a tendency to run characters together. If words are not being decoded correctly (spaced) try switching between the LONG, MEDIUM, and SHORT modes.

 Hint: If the characters are being decoded correctly but are spaced, switch to the LONG mode. Or, if the code being sent appears to have letters spaced close together (by ear) and is not being decoded at all, switch to the SHORT mode. The normal mode of operation is the MEDIUM mode


Spaces

        The space button allows spaces to be generated in the received text. This operation is optimal when the transmit operator has well-proportioned characters. Dots or dashes or spaces are evenly spaced apart).


Filter
Speed

The speed button allows for high speed CW decoding at the expense of processing signals in a noise environment. When the "50 wpm" option is selected the maximum CW decoding speed is about 50 wpm. When the "35 wpm " option is selected the top CW decoding speed is about 35 wpm. The 25 wpm speed CW processing works well when there is a high background noise level. For most CW processing the 25 or 35 wpm speed modes are adequate.

The spectrum display will change with the speed changes. The upper limit of the spectrum is about 2500 Hz in the HIGH speed mode and 1250 Hz in the LOW speed mode.

The 25 wpm tuning is more critical. The red vertical line must be tuned exactly on the peak of the spectrum of the signal that is being decoded. Use the AFC on "Narrow" to continuously track the CW signal.


Text Clear

        The CLEAR button when depressed will clear the received text on the display when the Op Mode is TEXT and will clear the transmit text window when the XMIT button is ON. The text will also automatically clear when the text display is full of 50 lines of characters. Watch the text decoding, if it text stops updating (freeze), then push the CLEAR button to start the LEARN processing again. This typically occurs during transmitter tuning (long carriers). Also, if moving from a low speed text decoding to a high speed text decoding push the CLEAR button to synchronize the decoding processing. This is not required when moving from high speed text to low speed text.


Sync

The Sync button allows synchronization of the transmit speed to the received code speed. Pushing the Sync button will set the transmit speed to the received speed as indicated on the WPM indicator. This is useful for insuring that the transmitted code speed is the same as the other operator in the QSO.


Overload

The Overload bar is Green when the signal level input to the sound card in the computer is within acceptable levels. It turns Red when the input level to the sound card is too high . Improper decoding of the CW signals may occur when the Overload bar is flickering Red. Reduce the audio level from the receiver or use the volume control panel to reduce the input.


Decoding Status

The decoding status indicator displays Red when the program is trying to determine the dot/dash intervals during a new signal. It turns Red and displays "Learn" when determining the intervals. It turns Green and displays "Done" when the intervals have been determined. Text decoding on the screen will occur only after the "Done" status is being displayed.


Xmit Enable

        The Xmit Enable button allows keying of a transmitter from the keyboard. This mode is useful for code practice and for keyboard QSOs. The transmit function is allowed in the MANUAL, and TEXT modes of operation, After the transmit button has been pressed select the code speed that is to used. Type on the keyboard to transmit characters. The transmit function operates in conjunction with the MANUAL, and the TEXT modes of operation. This allows full break-in CW operation. If another button is pressed on the program the transmit function will pause, click in the transmit text window to resume transmitting.


Xmit Tune

This button will key the transmitter to allow tuning of the RF path. Pushing the button twice will unkey the transmitter.


Send

This button will send the text that is in the lower text window after a RETRIEVE memory operation has been performed. The Xmit button must be ON. Each time the button is pushed the text that is in the memory location indicated by the Red M(1 through 10) button will be sent.


Loop

The LOOP button allows transmitted text to be repeated. If the LOOP button is on the text that has been selected by the Mx or Fx button will be repeated until the LOOP button is pressed again or until the XMIT Enable is OFF.


CLR MSG

This button allows clearing of one of 10 memory locations. To operate, push the CLRMEM button and then the memory (M1 through M10) button.


RECALL

This button allows retrieval of text from one of the 10 memory locations. To operate, push the RECALL button and then the memory (M1 through M10) button to retrieve the text.


STORE

This button allows storing of text in one of the 10 memory locations. To operate, type text in the lower window, then push the STORE button, and then the memory (M1 through M10) button.


IMM

This button operates in conjunction with the transmit button. When enabled the text typed in the lower text window to be transmitted if the XMIT button is ON. If other program functions have been operated, the IMM button (or clicking in the lower window) must be pressed to continue transmitting.


SCN

The SCN button allows text to be typed in the lower window without being transmitted until the SEND button has been pressed. This allows the lower screen to be edited before being sent.


M1 Through M10

Memory Buttons (M1-M10): These buttons allow for storage, retrieval, and clearing of text memory. Each memory location can store up to 1024 characters. When a memory button is activated the SEND TEXT button will send the data in the selected memory location.


Mic

The microphone input is the only option available at this time.


Right

The right line input to the sound card is not available as an option at this time.


Left

The left line input to the sound card is not available as an option at this time.


Line

The Spectrum Display menu selection allows the user to select whether the display is a spectrum graph of the receive audio or a Waterfall display. In the SCAN mode of operation the line will become green in color at the frequency that the decoding will take place.


Waterfall

The Waterfall display is useful for viewing a time line of the received signal. Intensity levels are color coded to enhance detection of the signal.


Auto

The auto threshold level sets the signal threshold at the quiet threshold level when the signal is below 250 points and to the noisy threshold level above 250 points.


Quiet

The quiet threshold selection set the signal threshold level at 1/4 between the noise floor and the peak signal level.


Noisy

The noisy threshold selection set the signal threshold level at just above mid way between the noise floor and the peak signal level.


Manual Threshold

The manual threshold allows the operator to manually control the threshold at which the program determines a tone is present. A line across the top screen gives a coarse indication of the threshold level. Use the lower status windows showing the signal level and signal threshold to set the threshold. Set the threshold value to about one half (1/2) of the peak signal level.


Windows Help

This menu selection brings up the Windows ® help menu system and this help file.


Version and Author

This menu selection displays a dialog box indicating the version number of the program and the author. The current version should be 2.1.14.


Frequency Select

        The frequency select slider is located under the graphical display. This control is used to select the audio signal of interest. Place the square slider beneath the desired frequency spectral line. This frequency will be the one that is processed if the operational mode is TEXT. A slight tuning of the receiver frequency may be required to maximize the signal level (spectral line) selected by the slider box under the display. When centered tuned, the CW signal on the display will be straddled by the red vertical line on the spectrum.

Another way to select a signal to be decoded is to click on the spectrum display where the signal is active. The frequency slider will move to where the mouse cursor is on the display. Use the Narrow automatic frequency mode when clicking the signals on the display.


Function Keys

Keyboard Function Keys (F1 through F10): These keys will transmit the text in memory locations M1 through M10 when the XMIT button is ON. Always insure that the cursor is in the transmit text window when using the Function Keys.


Escape Key

The escape key will terminate transmitting after the current character has been transmitted. The screen will be cleared and the transmitting mode will be the IMMEDIATE mode of operation.


Accent Mark Key

Accent Mark (') Key: This keyboard character has the same effect as pushing the LOOP Button.


Backslash Key

BACKSLASH (\) Key: The backslash key allows switching between the transmit text window and the receive text window (when in the MANUAL mode of operation). Each time the key is pressed the other (transmit or receive) text window is entered.


Operational Hints

Start running the program in the Text mode of operation. Tune the receiver until a CW signal is somewhere near the middle of the spectral display. Then set the slider box underneath the spectral line of the CW signal. Retune the receiver until the spectral (red) line is in the center of signal on the display. After several seconds the characters should start appearing on the screen. Again, adjust the signal gain until the characters that are being displayed do not have a large number of E's being shown within the text. This program operates best when there are medium to strong level signals. If you can comfortably read the signal, the program can decode the text. If there is considerable noise on the signal the text decoding will decode the static crashes as E's and may also miss other characters.


Problems

The program uses considerable system resources. A Pentium 166 MHz computer or faster should be used to run the program. If there are many other programs running simultaneously the program may lock up the computer. Close down the other programs and try again. If there are any other programs using the sound board there will be conflicts.

If there is no signal being displayed on the spectrum display you may have not selected the Mic IN as the signal source on the mixer panel, plugged the audio cable into the Mic input, or have the signal gain turned up adequately.

Connecting the computer to the Transmitter:

     The printer port may be used to control the keying of a transmitter. Bit 0 (pin 2) or bit 1 (pin 3) can be used for control where a HIGH (voltage high) turns the transmitter on and a LOW (voltage low) unkeys the transmitter. The default printer address is 3BC hex, use the option function on the menu bar to change the address that corresponds to LP1 on the computer. Input the new LPT address in Hex format. It is recommended that optical isolation is used when interfacing to the transmitter to prevent RF feedback from entering the computer.

        One of the serial communications ports (COM1 through COM6) may also be used to key the transmitter. Either the DTR or the RTS control line may be used, both are keyed at the same time. See the port setup form (Help menu) for the pin numbers on a DB9 or DB25 connector. Be sure to include a reverse diode on the input to the transistor to prevent reverse voltage breakdown of the device.


More Help

If you have any suggestions for improvement, E-mail them to WD6CNF@aol.com. Enjoy the program.

 (Grant, WD6CNF).


Uppercase

This menu selection sets the received Morse text to uppercase letters.


Lowercase

This menu selection sets the received Morse text to lowercase letters.


Normal

This menu selection sets the received Morse text to normal font.


Bold

This menu selection sets the received Morse text to bold font.


Output Port Selection

This menu selection will bring up a window that allows the operator to set the keying port during CW transmission. The menu options are selected by typing the correct address for the port being keyed.


Pro-Signs

ARRL Procedural Signals (Pro-signs)

 QRL?   Is the frequency in use

 CQ     Seek contact with another station

 AR     Over, end of message

 K      Go

 KN     Go only

 BK     Back to you

 R      Received

 AS     Wait, stand by

 SK     clear

 CL     Closing station


Q-Signal Summary

Q Signals

 QRA  What is the name of our station? The name of your station is _______ .

 QRG  Will you tell me my exact frequency (or that of ____)? Your exact

      frequency (or that of____) is _____ kHz.

 QRH  Does my frequency vary? Your frequency varies.

 QRI  How is the tone of my transmission? The tone of your transmission is _____.

     (1. Good; 2. Variable; 3. Bad).

 QRJ  Are you receiving me badly? I cannot receive you. Your signals are too

      weak.

 QRK  What is the intelligibility of my signals (or those of____)? The

      intelligibility of your signals (or those of___) is (1. Bad; 2. Poor;

      3. Fair; 4. Good; 5. Excellent).

 QRL  Are you busy? I am busy (or I am busy with____).

      Please do not interfere.

 QRM  Is my transmission being interfered with? Your transmission is

      being interfered with (1. Nil; 2. Slightly; 3. Moderately;

      4. Severely; 5. Extremely).

 QRN  Are you troubled by static? I am troubled by static____

     (1-5 as under QRM).

 QRO  Shall I increase power? Increase power.

 QRP  Shall I decrease power? Decrease power.

 QRS  Shall I send more slowly? Send more slowly (____WPM).

 QRT  Shall I stop sending? Stop sending.

 QRU  Have you anything for me? I have nothing for you.

 QRV  Are you ready? I am ready.

 QRW  Shall I inform____ that you are calling on _____kHz?

      Please inform_____ that I am calling on _____kHz.

 QRX  When will you call me again? I will call you again at _____.

      hours (on _____ kHz).

 QRY  What is my turn? Your turn is numbered _____.

 QRZ  Who is calling me? You are being called by____

      (on _____ kHz).

 QSA  What is the strength of my signals (or those of___)?

      The strength of your signals (or those of____) is

      (1. Scarcely perceptible; 2. Weak; 3. Fairly good;

      4. Good; 5. Very good).

 QSB  Are my signals fading? Your signals are fading.

 QSD  Is my keying defective? Your keying is defective.

 QSG  Shall I send_____ messages at a time? Send_____

      messages at a time.

 QSK  Can you hear me between your signals and if so

      can I break in on your transmission? I can hear

      you between my signals; break in on my transmission.

 QSL  Can you acknowledge receipt? I am acknowledging receipt.

 QSM  Shall I repeat the last message which I sent you, or some

      previous message? Repeat the last message which you

      sent me(or message(s) numbers(s)_____.

 QSN  Did you hear me (or____) on ____kHz? I did hear you

      (or____) on ____kHz.

 QSO  Can you communicate with____ directly or by relay?

      I can communicate with____ direct (or by relay

      through____).

 QSP  Will you relay to ____ ? I will relay to ____.

 QST  General call preceding a message addressed to

      all amateurs and ARRL members. This in effect

      "CQ ARRL".

 QSU  Shall I send or reply on this frequency (or on____ kHz)?

      Send or reply on this frequency (or ____ kHz).

 QSV  Shall I send a series of Vs on this frequency

      (or on ____ kHz)? Send a series of Vs on this

      frequency (or on ____ kHz).

 QSW  Will you send on this frequency (or on ____ kHz)?

      I am going to send on this frequency

      (or on _____kHz).

 QSX  Will you listen to ____ on ____ kHz? I am

      listening to ___ on ____ kHz.

 QSY  Shall I change to transmission on another frequency?

      Change to transmission on another frequency

      (or on ____ kHz).

 QRZ  Shall I send each word or group of words more than once?

      Send each word or group twice (or ____ times).

 QTA  Shall I cancel message number ____ ?

      Cancel message number ____.

 QTB  Do you agree with my counting of words? I do

      not agree with your counting of words. I will

      repeat the first letter or digit of each

      word or group.

 QTC  How many message have to send? I have

      messages for you (or for___).

 QTH  What is your location? My location is ____ .

 QTR  What is the correct time?

      The correct time is ____ .

 QTV  Shall I stand guard for you? Stand

      guard for me.

 QTX  Will you keep your station open for further

      communication with me? Keep your station

      open for me.

 QUA  Have you news of ____ ? I have news of ____ .


Off

When the Afc (automatic frequency control) option is in the Narrow, Medium, or Wide mode the program will lock on to a CW signal. The amount of the spectrum in which the lock range is determined is set by the Narrow, Medium, or Wide Afc options. There is no automatic frequency control when the Off mode is selected.


Narrow

When the Narrow automatic frequency control is selected the program will lock on to a CW signal when it is within 100 Hz of the frequency slider. Use this mode when there are many signals in the spectrum.


Medium

When the Medium automatic frequency control is selected the program will lock on to a CW signal when it is within 200 Hz of the frequency slider.


Wide

When the Wide automatic frequency control is selected the program will lock on to a CW signal when it is within 400 Hz of the frequency slider. This mode is useful when there is a "QSO" in progress and the two stations are not on the same (but close) frequencies.


Small Font

Use the smaller font size when you want to see a large amount of text on the screen. The font size affects both the receive and transmit screens. All other font attributes (bold and upper/lower case) still apply.


Normal Font

Use normal font for the best compromise between readability and a large amount of text on the screens. The font size affects both the receive and transmit screens. All other font attributes (bold and upper/lower case) still apply.


Medium Font

Use medium font for a more comfortable viewing of the text screens. The font size affects both the receive and transmit screens. All other font attributes (bold and upper/lower case) still apply.


Large Font

Use large font for the most comfortable viewing of the text screens. This size font is also useful for viewing the text from across the room. The font size affects both the receive and transmit screens. All other font attributes (bold and upper/lower case) still apply.


COM1

To connect the computer to a transmitter an output from the computer must be selected. There are 4 com ports available and two printer ports available. All ports are available for Windows95, Windows98, and WindowsME. Only the com ports are available for Windows2000 and WindowsXP. For the parallel ports (LPT1 and LPT2) use pins 2 or 3  (pin 25 in gnd) to key the transmitter through a driver interface. For the serial ports (9-pin) use pins 4 and 7 (pin 5 is gnd) to key the transmitter through a relay buffer interface. For computers running WindowsXP and Windows2000 that do not have a serial port, use a Serial Port to USB adapter.


COM2

To connect the computer to a transmitter an output from the computer must be selected. There are 4 com ports available and two printer ports available. All ports are available for Windows95, Windows98, and WindowsME. Only the com ports are available for Windows2000 and WindowsXP. For the parallel ports (LPT1 and LPT2) use pins 2 or 3  (pin 25 in gnd) to key the transmitter through a driver interface. For the serial ports (9-pin) use pins 4 and 7 (pin 5 is gnd) to key the transmitter through a relay buffer interface. For computers running WindowsXP and Windows2000 that do not have a serial port, use a Serial Port to USB adapter.


COM3

To connect the computer to a transmitter an output from the computer must be selected. There are 4 com ports available and two printer ports available. All ports are available for Windows95, Windows98, and WindowsME. Only the com ports are available for Windows2000 and WindowsXP. For the parallel ports (LPT1 and LPT2) use pins 2 or 3  (pin 25 in gnd) to key the transmitter through a driver interface. For the serial ports (9-pin) use pins 4 and 7 (pin 5 is gnd) to key the transmitter through a relay buffer interface. For computers running WindowsXP and Windows2000 that do not have a serial port, use a Serial Port to USB adapter.


COM4

To connect the computer to a transmitter an output from the computer must be selected. There are 4 com ports available and two printer ports available. All ports are available for Windows95, Windows98, and WindowsME. Only the com ports are available for Windows2000 and WindowsXP. For the parallel ports (LPT1 and LPT2) use pins 2 or 3  (pin 25 in gnd) to key the transmitter through a driver interface. For the serial ports (9-pin) use pins 4 and 7 (pin 5 is gnd) to key the transmitter through a relay buffer interface. For computers running WindowsXP and Windows2000 that do not have a serial port, use a Serial Port to USB adapter.


LPT1

To connect the computer to a transmitter an output from the computer must be selected. There are 4 com ports available and two printer ports available. All ports are available for Windows95, Windows98, and WindowsME. Only the com ports are available for Windows2000 and WindowsXP. For the parallel ports (LPT1 and LPT2) use pins 2 or 3  (pin 25 in gnd) to key the transmitter through a driver interface. For the serial ports (9-pin) use pins 4 and 7 (pin 5 is gnd) to key the transmitter through a relay buffer interface. For computers running WindowsXP and Windows2000 that do not have a serial port, use a Serial Port to USB adapter.


LPT2

To connect the computer to a transmitter an output from the computer must be selected. There are 4 com ports available and two printer ports available. All ports are available for Windows95, Windows98, and WindowsME. Only the com ports are available for Windows2000 and WindowsXP. For the parallel ports (LPT1 and LPT2) use pins 2 or 3  (pin 25 in gnd) to key the transmitter through a driver interface. For the serial ports (9-pin) use pins 4 and 7 (pin 5 is gnd) to key the transmitter through a relay buffer interface. For computers running WindowsXP and Windows2000 that do not have a serial port, use a Serial Port to USB adapter.


NONE

This output port will be selected when there is an invalid or missing output port. It is also the default selection to prevent program error messages when running the program for the first time.


Enable

The Enable Time Line menu selection opens a separate window that displays the decoded signal in a graphical display. The window is scaleable in time in the horizontal direction and scaleable in amplitude in the vertical direction. The maximum screen size is 1200 x 1600 pixels and the size  and location of the window is retained after the window is closed.

The time line display shows four separate graphical lines; a red line which depicts the logic up/down state of the decoded CW signal, a black line which shows the actual decoded signal, a blue line which shows the calculated threshold for a one or zero detection, and a brown line which shows the average noise floor.

The time line window may be paused or continued with control buttons on the bottom of the window. To close the time line display click the close button or the "x" on the upper right hand of the window.


Nx Blank

The Nx Blank button enables a noise floor clipper for the decoded CW signal. Clicking the button enables clipping and clicking it again will disable the clipping.

Clipping the noise floor will help in reducing the noise of the decoded signal in some (but not all) noisy band conditions.


Filter OFF

The filter OFF menu selection will disable the noise reduction algorithm during the processing of the CW signal.


Filter ON

The Filter ON menu selection will enable a noise reduction algorithm during the processing of the CW signal. The noise reduction algorithm will work best with very weak signals. Stronger signals (higher SNR) dol not need to have any reduction in noise to decode the signal. It is recommended that this option remains ON unless there is a problem running the program on older computers (< 300 MHz speed).

The state of the filter enable is saved when the CW DecoderXP program is terminated.


Timeline Display Window

Please refer to the Time Line menu selection topic.


Rx Coarse

The Rx Coarse slider sets the CW Decoder coarse receive gain. It is intended to compensate for different sound card gains in different computers. Use the slider to set the signal level to where the spectrum display is showing the received signal at the full height of the display. Use the Rx Gain for easy fine adjustment.


On

This selection turns on the signal fading control. It is useful when the there are medium to strong signals with considerable fading. Turning this control ON will allow any energy above the noise to be the guiding threshold rather the than the average signal threshold level. This function is best used with the Nx Blanking control. It may add more false character decoding during weak signal conditions.


Fade OFF

This selection turns off the signal fading control.