Motorola VRS750, Service Manual

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****** If a failure occurs, go to STEP 3 otherwise proceed
9. Press Toggle Bias again to disable the PA Bias softpot.
10. Program the Bias softpot into the radio’s codeplug via pressing
Program .
11. Exit the PA Bias Low Power function.
STEP 2 1. Increase Y until Y-X is within the range given for PA current in
Table 14 ( STEP 2 ).
2. Press Toggle Voltage again to disable the PA control voltage edit
box/spin control.
3. Press Toggle Bias in order to enable the PA Bias softpot.
4. Increase the softpot value to obtain Z until Z-Y is within the
range for Bias Current as indicated in Table 14 ( STEP 2 ).
****** If a failure occurs, go to STEP 3 otherwise proceed
5. Press Toggle Bias again to disable the PA Bias softpot.
6. Program the Bias softpot into the radio’s codeplug via pressing
Program .
7. Exit the PA Bias Low Power function.
STEP 3 1. Press Toggle Bias twice to reset the softpot value.
2. Press Toggle Bias again to disable the PA Bias softpot.
3. Measure/read the dc current drawn from radio (specifications will
vary from radio to radio). Call this X . This value should typically
range from 70-100 mA or 0.07-0.1 A.
4. Press Toggle Voltage to enable the PA control voltage edit box/
spin control.
5. Increase the Voltage softpot value and measure/read from current
meter. Call the new value Y .
6. Increase Y until Y-X is within the range given for PA current in
Table 14 ( STEP 3 ).
7. Press Toggle Voltage again to disable the PA control voltage edit
box/spin control.
8. Press Toggle Bias in order to enable the PA Bias softpot.
9. Increase the softpot value to obtain Z until Z-Y is within the
range for Bias Current as indicated in Table 14 ( STEP 3 ).
Table 14. PA Bias Low Power Specification for VRS750s (UHF Only)
Step PA Current (mA) Bias Current (mA)
STEP 1 20-30 630-750
STEP 2 30-45 750-900
STEP 3 40-55 600-750