Hal Communications CWR6850, Instruction Manual

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CHAPTER 2 PAGE 10
To transmit RTTY, make sure that the XMIT AUDIO GAIN control (of the transmitter) is set to mini-
mum, turn the transmitter on with either its TX ON control or use the CWR6850 SEND switch (lev-
er up). Increase the XMIT AUDIO GAIN until some RF output is obtained, tune the transmitter if
necessary and set the XMIT AUDIO GAIN to the recommended power level for RTTY (see your
transmitter manual). After tuning and adjusting, turn off the transmitter with the transmitter
switch or switch the CWR6850 to RECEIVE (lever down). Type the text to be transmitted on the
CWR6850 keyboard – it will be displayed on the bottom three lines of the screen (dotted line
area). When you are ready to transmit, move the CWR6850 switch to AUTO (lever middle position)
and type "CTRL-A" ("A" character appears on status line with the "P" character). The KOS (Key-
board Operated Switch) circuit of the CWR6850 will turn the transmitter on and the text will be
transmitted. The transmitter will turn off automatically when all of the text has been transmitted;
additional typing of text will turn the transmitter back on and the new text will then be transmitted
(after a short delay to allow transmitter relays to switch). You may listen to the output RTTY tones
through the CWR6850 sidetone monitor system, controlled with the VOLUME slide control. The
transmit text may be stopped at any time by switching to RECEIVE or by typing "CTRL-A" again (or
with "CTRL-X").
The transmit section of the CWR6850 is placed in "continuous mode" when it is first turned on;
that is, characters are transmitted one-at-a-time, as the are typed. Word mode can also be used
by first typing "CTRL-Y" ("Y" character appears on the status line). Now, text is transmitted a word
at a time, allowing you to back-up and correct spelling errors before they are transmitted. The last
word typed is not released to be transmitted until after you have typed a space bar character.
Word mode and other transmit features are discussed in detail in Chapter 4. Programming and use
of the HERE IS and CWID memory features are discussed in section 4.3 of this manual.
2.5 Morse Operation
To use the CWR6850 for Morse code reception, change the CW / RTTY button to CW (button out).
Leave the transceiver mode in LSB for the present and tune to a Morse code signal. When the re-
ceiver is correctly tuned, the audio beat note will be approximately 800 Hz and the CW LED on the
CWR6850 front panel will flash in sync with the key-down condition of the signal You may monitor
the code as processed by the CWR6850 by adjusting the VOLUME slide control; the Morse decod-
ing circuit drives the internal sidetone oscillator. Since the sidetone oscillator is set to approxi-
mately 800 Hz, you may compare its frequency to that of the received signal by adjusting the two
slide controls INPUT and VOLUME, and tuning the receiver until they match. The INPUT control ad-
justs the volume of the received signal and VOLUME adjust the volume of the regenerated side-
tone output. This technique gives a very accurate way of optimizing the tuning. You should now
see a display of the received Morse code signal.
If the CW signal you are listening to is weak or if interference is strong, try using the CW filter in
the receiver, if one is available. Most transceivers couple the mode switch to the filter selection, so
you may have to switch now to CW MODE on the transceiver. When switching to CW from LSB
mode, you will probably have to return the receiver to maintain reception of the desired CW signal.
Be sure that the CWR6850 switch is set to RECEIVE before switching to CW to avoid inadvertent
operation of the transmitter. The CWR6850 itself has a narrow-bandwidth PLL (phase-lock-loop) fil-
ter that may be used in addition to that in the receiver. To use the CWR PLL CW filter, push the
FILTER ON button in. This filter considerably narrows the audio bandwidth of the CWR6850 (to ap-
proximately 80 Hz) and the CW detection circuitry will no longer "track" the frequency of a drifting
Morse code signal. Use the PLL filter only when noise and interference are causing poor "copy".
The CWR6850 [ SPACE / NARROW ] button may be depressed to compensate for signals with in-
correct letter and word spacing, reducing the space required between words for display of a space
on the screen. This feature may cause interpretation errors in the display of Morse characters and
should be used sparingly!