LBI-33057
9
Figure 6 - Test Setup
Reference Oscillator
Reference Oscillator U3 is factory adjusted and
should not normally need readjustment Use a
recently calibrated and stable frequency
counter to determine if oscillator alignment is
needed. This test/alignment should be done at a
room temperature of 25° C
±
5°C.
1. On the TQ-0609 Test Box, select UDC switch
position 6 and apply power to the radio. This en-
ables the radio's control circuits for an external
microphone and its internal speaker amplifier.
2. Channel the unit to the MIDDLE test channel
listed in Table 2 (low-power) and key the
transmitter using the TQ-0609. DO NOT apply
any modulation at this time.
3. Monitor transmitter frequency and adjust Refer-
ence Oscillator U3 to a frequency reading of
within 50 Hz (a small trimmer hole is located on
top of module). If the
±
50 Hz maximum error (at
room temperature) cannot be established, Refer-
ence Oscillator replacement may be necessary.
Table 3 list maximum transmitter errors for the
specified temperature range.
4. Check all TX test channels for an error of less
than
±
50 Hz.
Modulation Adjustments
1.
To align R18 and R19 it will be necessary to modify
the RF/Logic Extender cable as follows:
•
Add two 10K ohm resistors in series from 5.5
Vdc (J102 pin 6) to ground (J102 pin 7).
NOTE
