9-24

Troubleshooting Charts: RX RF

 

 

 

RX RF—Page 5

68

Measure preselector filter

tuning voltage dac1 and dac2. UHF: TP401, TP405

dac1 = dac2?

No

 

Replace

 

 

PCIC

 

 

 

 

 

 

 

Yes

Tune the radio across several

channels. Measure dac2, proportional to frequency.

Dac

No

Replace

voltages

 

 

 

PCIC

OK?

 

 

 

 

Yes

 

 

 

 

 

 

 

 

 

 

Check discrete

 

 

preselector filters.

 

 

7

Remove IF filter shield. Check IF filter and LC matching networks.

UHF: SH403

Visual

No

Repair

inspection

 

defects

OK?

 

 

 

 

Yes

 

 

 

 

 

 

 

 

 

Replace IF filter.

 

 

UHF: FL490

 

 

Band

F (MHz)

dac2 (Vdc)

UHF

470

2.9

MAEPF-27474-B

November 11, 2004

6881094C12-A

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Image 128
Motorola SSETM 5000 service manual Uhf