SCS Tracker Installationsanleitung Seite 30

3. Installation
- For 9k6 Packet-Radio:
Signal
GND
PTT
AF-OUT
AF-IN
This cable is available completely assembled.
Refer to chapter 5 on page 28.
3.3.4 Amplitude Adjustment
The output amplitude of the TNC is set with the %X command. The level range is 30...3000
mV p-p. %X sets all levels for all modulations at the same time to the value given as argument.
%XF sets the 9k6 / 19k2 (G3RUH) FSK level. %XA sets the 300 / 1200 baud AFSK level. %XR
sets the output level for the Robust HF Packet modulation.
The TNC's output amplitude has to be adjusted very carefully to the connected transceiver. If
you don't pay attention on this item a corrupted signal much too wide will be the result!
The audio input sensitivity of most transceivers mainly designed for voice operation is adapted
to the output voltage of a common dynamic microphone. 100% modulation is reached at low
mic gain settings with 200 mV (peak to peak) input voltage. It is not recommended to use very
high output values and compensate this by lowering the mic gain setting, because this may
already overdrive the first amplifier stages which are very sensitive and located in the signal
path before the mic gain controlling device. We recommend for the first approach to use the
default output values and then regulate the output power with the mic gain setting (if available)
and watching the ALC meter in case of an SSB transmitter. The ALC level should not exceed
the admissable range. To do this connect the TRX to a dummyload resistor capable to dissipate
the power or to an antenna with good SWR (take care that the frequency being used is not
already occupied).
Start a terminal program that allows direct input of TNC commands (e. g. HyperTerm). Select
the desired operating mode (%B command) and then adjust the corresponding %X(A/F/R)
setting to an appropriate starting level (default settings: %XA=200, %XR=300, %XF=600).
Make sure that the I-Parameter ("Mycall") is set to your callsign. (If the "mycall" is still set to
"DSP TNC", transmitting will be generally inhibited.) Now your TNC is ready for sending
"Unproto" data packets through the virtual TNC channel 0 (also called "monitor channel").
Data received by the TNC on virtual channel 0 from the serial port (USB) and terminated with
a <CR> will be sent out as unproto packets. In fact, every time pressing <RETURN>
(=sending a <CR> to the TNC) a short transmission burst will be triggered. You can use the
mic gain knob to increase the transmitting power until the ALC voltage reaches the allowed
limit.
For all modes using FM instead of SSB (usually 1200 Bd AFSK and Direct-FSK) you need to
measure the FM deviation for optimum results. In practise (no deviation meter available) start
with fairly low %XA/XF signal levels, connect a nearby digipeater and increase the TX audio
level until no or almost no "retries" are requested. Then increase the signal level another 10-20
%.
24
TNC Color
PIN 2 white
PIN 3 yellow
PIN 1 violet
PIN 4 green
Table 10: YAESU 6 pin Mini-DIN
YAESU
PIN 2
PIN 3
PIN 1
PIN 4