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 mothe13.8 VDC line
+13.8 VDC**
TP2
Reg9.5 VDC from motherboard
+9.5 VDC ± 5 %
TP9
Sw13.8 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 specified 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 specified (see the VHF and UHF Receiver Performance
Specifications 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 Specification Data Sheets (located in this manual)
for the full Supply Voltage range.
