Low transmit power output on Low Band CDM 1250

[mmb]

I recently purchased a low band cdm 1250 off eBay, it looks brand new & receives excellent. It has very low transmit power output, around 3 watts on all channels...would this be worth taking to a shop & having fixed or should I just keep it like it is..

Thanks in advance
Charles
KI4DCR

[Bill_G]

Yes - if for no other reason than to do a sanity check on your wattmeter and cable. ymmv

[Karfield]

Now, I'm pretty positive that the low band CDM did not come in a BJT format plus it sounds like you have a newer unit anyway so, here is the part number for the PA on that low band CDM.

4886136B01 x2

Pretty easy change out just need a head gun. Also, if the board is "stuck" to the heatsink just throw a little heat around the PA and Audio PA areas and gently pry up the board.

[d119]

Or just make sure the lid of the radio is seated properly. Don't these radios have a pressure sensitive switch in them that can cause this type of behavior?

[Karfield]

The pad you are refering to will make it so the radio doesn't key up. I believe what the pad does is cause a short in the B+ or the control line which enables the PA. I've never looked into it. But I do know that if you take the board out and key the unit up it'll last about 10 seconds before burning out. LOL

The reason why I gave the part numbers is cause that was the number one failure for Low Band CDM's. Generally it'll just be 1 PA but you should replace them both. Just be careful they do have a polarity.