Service manual

August 30, 2002 99R85452E01-O
3-4
Radio Tuning
: Hardware Tuning Setup and Procedure
3.4.2 Sub-Audio Modulation Tuning
1. Set the radio to transmit at the appropriate tuning frequency (See “Tuning Frequency” on
table 3-1) with low power and TX PL frequency of 100.0Hz. Set Channel Spacing to "CS-
25.0" for 25kHz (see “Radio Programming” section).
2. On the test equipment, set it to receive at the appropriate tuning frequency (see “PRO2150
Portable Radio Programming” section) and with the following configurations:
Audio bandwidth: 0.25Hz to 3,000Hz.
De-emphasis: OFF
3. Do NOT inject any tone to the radio.
4. Key up the radio.
5. Using a ceramic tuning tool, adjust RV602 to tune the sub-audio modulation deviation to
settle between 0.65kHz to 0.75kHz.
3.4.3 Tuning Frequency
Table 3-1.
Band Frequency (MHz)
VHF 136-174 MHz 155.025
UHF 403-440 MHz 421.5
UHF 435-480 MHz 457.5