Kenwood TM-733A. No transmit, no receive. Passes factory display check, all controls report back proper codes. No receive audio on VHF. Squelch is open. UHF has receive audio and squelch does silence it. No receive either band. No transmit either band. No power thru Bird wattmeter, nothing shows up on spectrum analyzer. I checked fuses and holders, power supply connections, 13.8 volts at the board inside the radio. I did a full reset to make sure there were no settings corrupted or mis-set that would cause these issues. I noticed that the VCO voltage was out of range on UHF (.61 volts, should be 2.5 to 5.0). Voltage is 3.4 volts. I have an original service manual with all schematics and pictorials. Nowhere is there any mention of a way to adjust the VCO voltages. Does anyone have any experience with this issue? Any help appreciated.
Kenwood: TM-733A No xmit, no receive
- Thread starter bbo14
- Start date
Is there a PIN diode somewhere in the RF section that switches between VHF and UHF?
Hello. No, there are PIN diodes in each RF deck to steer between transmit and receive, but I see none to switch between VHF and UHF. This radio does not use low pass and high pass filters because it has two independent antenna lines, one for VHF and the other for UHF.
