5. Check to see that the TPI de voltage drops to a level
between 0.6 and 1.0 volts. As long as the de level stays
between 4.5Vdc for transmit on channel 40 and 0.6 to l.OVdc
for receive on channel 1, the VCO is set properly.
The magnitude of the TPI voltage swing is determined by C216
at the factory. The optimum value of C216 was found to be
around 82 pFd. C216 with a value larger than 82 pFd will
reduce the voltage swing magnitude and vice versa for a
smaller value. If the lower value drops only to 1.5Vdc,
then a C216 of 82 pFd should be reduced to increase the
range. This should not be necessary when factory supplied
parts are used for D208 (Varactor Diode) and L201 (VCO
Tuning Coil).
TRANSMITTER ALIGNMENT
a. Test Set-up
Volt Ornent
Meter Meter
Note:
Transmitter Alignment Set Up
1. When connecting audio cable to the microphone input circuit,
always use shielded cable.
2, When making alignment for RF power output, always use the
supplied de cable.
b. RF Amplifier State Alignment
1. Reduce power supply voltage to 9.0V.
2. Set channel selector to 19 and connect the oscilloscope to
the antenna connector through a suitable connection pad.
19 PLUS -9-
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