User's Manual

3-10
6. Key the transmitter and input a +10 dBm (2.5 VRMS), 2.5 kHz audio signal into
microphone input 1 if in single mode or microphone input 2 if in dual mode.
7. Adjust the wideband deviation limit potentimeter, R30 on the UHF Rx/Tx module (see
Figure 3-6) to produce a ±4.25 kHz deviation. Select narrow band mode on the UHF
band and adjust the narrowband deviation limit potentimeter, R76 on the UHF Rx/Tx
module to produce a ±2.15 kHz deviation.
8. Verify that the deviation does not exceed ±5 kHz for wideband and ±2.5 kHz for
narrowband on 403.000 MHz, and 512.000 MHz. Re-adjust R30 or R76 as required,
if the deviation exceeds ±5 kHz or ±2.5 kHz, respectively.
9. Replace the bottom cover.
VHF Receiver/Transmitter PCB Module
Notes: R30 is for 25 kHz (wideband) Deviation Adjustment
R76 is for 12.5 kHz (narrowband) Deviaton Adjustment
FIGURE 3-5 Deviation Adjustment Potentiometer Location