Timewave DSP-232, Operating Manual, Page: 141 / 271

Chapter 8 ASCII and Baudot Operation
4. Tune your receiver between 14.08 and 14.10 MHz (or elsewhere where there’s Baudot or ASCII activity).
5. Slowly vary the tuning control on your receiver while glancing at the DSP’s tuning indicator. Look for the
LED pattern below and adjust the frequency control accordingly.
Frequency too low Tuned in! Frequency too high
6. When you find a station, adjust the threshold using either the THRESHLD or AUTOT commands (for an
explaination of these commands refer to chapter 4). Adjust the threshold so the DCD light glows when a
tuned Baudot or RTTY station is being received, but goes out when no signal is received.
With a good signal and your DSP properly tuned in, text should start to appear on your screen.
If the text you’re receiving is garbled, you may be tuned to a transmission at a different baud rate. Either try tuning
in a different station, or see
Chapter 11: SIAM, TDM, and NAVTEX Operation about having the DSP determine the
type of station you’re listening to for you.
Note : Many RTTY stations found outside of the Amateur bands don’t transmit in plain text—they use a
sophisticated encryption technique that makes receiving them almost impossible. There are a few stations,
however, that use a relatively simple bit-inversion technique to make them hard to copy. For these
stations, use BITINV to decode these simple forms of encoded RTTY stations.
Going on the Air
Note : Make sure your DSP is adjusted for your SSB transmitter as described in Chapter 3: Radio
Installation , under the heading SSB Transceiver Final Adjustments . These are critical adjustments. If your
DSP’s AFSK level and transmitter’s mike gain aren’t adjusted properly, other stations won’t be able to
copy your signals.
Finally, before you go ahead and transmit, here are some helpful hints:
♦
Don’t use the VOX control—use the PTT line from your DSP.
♦
Turn off all compression or other transmitter audio processing.
♦
If you’re using an AFSK audio input, keep the audio level to the microphone input circuit as low as
possible to avoid overdriving the audio input stages.
♦
Adjust the transmitter’s drive to prevent excessive ALC action; use more effective RF antenna loading to
adjust output power levels.
Before you transmit, however, you have to decide if you’re going to “call CQ” or answer someone’s CQ call.
Calling CQ
As with most amateur operating modes, you can start a contact either by calling—or answering—(a) CQ. To call
CQ:
1. Enter X to key your transmitter.
2. Type in your CQ message. For example:
CQ CQ CQ DE WF7A WF7A WF7A
(
RETURN
)
CQ CQ CQ DE WF7A WF7A WF7A K ( RETURN ) ( RETURN ) ( CTRL+D )
By entering a ( CTRL-D ) at the end of your CQ call, it puts both your radio and the DSP into the receive mode.
3. After the DSP has sent your CQ, wait a bit for a response; if you don’t get one, repeat the above procedure
on the same—or another—frequency.
September, 05 8-3