Timewave DSP-232, Operating Manual

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Chapter 3 Radio Installation
8. Connect the brown wire to the main ground on the connector. This ground is the one used for the PTT and
receive audio. You should connect the Silver Shield/Drain wire to this ground only if there isn’t a separate
mike ground as described in the previous step.
For PTT, the DSP keys only positive (+)PTT since most transceivers use this method of keying. If you’re
connecting a handheld (“handy-talkie”) transceiver to your DSP, you’ll probably need a resistor and/or capacitor to
isolate this connection from the AFSK audio. (Check
Appendix A ).
Connect the green wire to the Receive Audio terminal on the connector. If the connector you’re wiring doesn’t have
Receiver Audio available, then the included 3.5 mm audio cable may be used instead. This cable connects audio
from your transceiver’s external speaker/earphone jack to the RX AUDIO jack on the DSP. If you’re connecting to
an Accessory jack, make sure the available level is at least 200 mV
RMS
.
Connections for Direct-FSK on RTTY
Some HF SSB radios provide direct FSK (Frequency-Shift Keying) for RTTY, AMTOR and PACTOR operation.
Note : when using narrow filters they can limit the data transfer rate at 110 baud. Consult your
transceiver’s manual regarding direct FSK operation for further recommendations.
To install and operate your DSP and radio in the FSK mode, connect a shielded cable from the DSP’s FSK/AUX
(DIN) receptacle, pins 1 or 4, to the radio’s FSK input. (See Figure 3-3 below.)
Note : polarity of the FSK signals aren’t standardized by radio manufacturers—Icom radios most often use
FSK-N, while Kenwood radios most often use FSK-R. Consult your transceiver’s manual to identify the
proper polarity, its power and duty cycle limits so they won’t be exceeded.
Figure 3-3 AUX/FSK Pin Assignments
Transceiver Adjustments
!
Very Important: MAKE SURE YOUR DSP AND RADIO ARE OFF AND ALL THE CABLES ARE
CORRECTLY WIRED AND CONNECTED.
This section is split into separate procedures for FM and HF SSB radios. If you’re connecting an FM transceiver to
one of the radio ports, then we recommend that you adjust that radio, first. This will establish the AFSK level from
the DSP. If the only radio you will be connecting is an HF SSB transceiver, then skip the FM section and proceed
directly to the
HF SSB Final Adjustments section.
FM Transceiver Adjustments
1. Connect a dummy load to your radio and be prepared to monitor your transmissions with another nearby
radio such as a handheld transceiver.
3-4 September, 05