Batboard

I have a low band low split maratrac with awful receive (won't open until about 10uv). I have done some research and there seems to be a protection diode that goes bad. I use an R2600B to check the radio. I checked it against a low split maxtrac and the maxtrac is fine at .30uv.

What is the component number and where can I find this (what board and where?)?

Any other info appreciated. One other thing is while this is a low band radio the squelch pot on the head doesn't open the squelch. A steady press of the MON button will.

It should be a surface mount dual-diode (48-80154K03 Schottky type), component number CR2, located on the bottom of the RF board. It's along the rear edge of the board, there's a row of chip caps right along the edge of the board with one three pin diode in there.

There's also a possibility of the RF amp being bad. Do you have a service manual?

Yes i found it. I have an old RF board from the high split low band maratrac and will swap with one on there. Thanks. I have the manual.

I finally got around to replacing the diode. It was visually bad with a burn spot on it. I replaced it and the receive got a lot better, but still not great. It went from 10.0 to 3.0 uv. How can I test the RF amp?? Any other direction I should go??

You could check the RF transistor with the diode test function on a multimeter, checking it in circuit might show if it's shorted, but you might need to carefully remove it to do a good test on it.

Also Maratracs have an antenna relay, so you could check that. I think you should be able to check for continuity from the antenna jack to the center pin of the plug that goes into the RF board receive input. If you can connect your generator right into the RX jack on the RF board you can check sensitivity there without going though the relay. That's assuming there's a jack on the board, some radios had the cable soldered in.