Motorola APX 3000 Detailed Service Manual page 123

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Table of Contents

Troubleshooting Charts: RX RF Failure

RX RF Failure – Page 7

Remove SH2 and SH1.

Measure RF and IF level at mixer

and compute mixer conversion

For UHF1/UHF2 radios:

Non gnd of C1900 and output of L503

For 7800 radios:

Input of C488 and output of L503.

For VHF radios:

Input of R316 and output of L503.

Mixer gain about

Note: RF Test frequency used:

UHF1: 424.975MHz

UHF2: 485.075MHz

VHF: 154.275MHz

Measured with a High Frequency Probe for relative comparisons and troubleshooting

only. Actual S21 gain or loss may differ if the test point is not 50 ohms.

Troubleshooting