User's Manual

MT-4E VHF & UHF Receiver & Transmitter Instruction Manual
IM08-MT-4E-TXRX-P1162
VHF & UHF Hardware Tuning and Troubleshooting
16
Receiver Mainboard
Check the following test points on the receiver mainboard:
Test Point Signal Monitored Typical Voltage
TP1 Voltage from motherboard +13.8 VDC line +13.8 VDC**
TP2 Regulated +9.5 VDC from motherboard +9.5 VDC ± 5 %
TP9 Switched +13.8 VDC line from front panel switch +13.8 VDC**
TP37 +6.0 VDC supply +6.0 VDC ± 5 %
TP38 -6.0 VDC supply -6.0 VDC ± 5 %
TP54 +3.3 VDC supply +3.3 VDC ± 5 %
TP55 +1.2 VDC supply +1.2 VDC ± 5 %
TP56 +1.8 VDC supply +1.8 VDC ± 5 %
TP57 +2.5 VDC supply +2.5 VDC ± 5 %
TP58 +5.0 VDC supply +5.0 VDC ± 5 %
Test Points are shown on the VHF / UHF Receiver Jumper and Test Point Locator Illustrations.
If the test point voltages are within the specied range, the following tests further verify that the
receiver mainboard may not be the source of problem.
Apply a -30 dBm IF signal of the frequency specied (see the VHF and UHF Receiver Performance
Specications data sheet) to the receiver mainboard IF Input SMB connector. If the signal is properly
demodulated it proves that the receiver mainboard and UDB are in working condition. Proceed to
troubleshooting the synthesizer and UDB module.
** Refer to the Specication Data Sheets (located in this manual)
for the full Supply Voltage range.