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RR Spectra Receive Problem

Posted: Sat Dec 13, 2008 3:49 pm
by chezelle
Hello,

I got a Railroad Spectra that worked great except that the antenna connector was broken on it. I got a new Motorola antenna connector and cable and instead of just soldering on the connector end I pulled the radio apart and soldered in the new connector coax cable and all. Put it back together and now it has almost no to very weak receive. You have to be very close for it to p-up anything at all and I'm within a mile of a mainline railroad and hear nothing. I took it back apart a few times and checked everything but can't find anything wrong. Nothing pinched anywhere and everythings connected good. Could it possibly need re-aligning just for splitting it and replacing the antenna cable? The only other thing I can think of that was different is the replacement antenna connector coax was a little thicker than the original coax but its not pinched anywhere. Any suggestions before I have to take to a shop?

Thanks,
Brian

Re: RR Spectra Receive Problem

Posted: Sat Dec 13, 2008 4:48 pm
by thebigphish
stupid question.

did you tone out the antenna feed line & test the antenna on another RX unit?

Re: RR Spectra Receive Problem

Posted: Sun Dec 14, 2008 6:30 am
by chezelle
The antenna feedline and antenna are ok. I'm talking about the coax inside the radio. Thats all that was changed and then I lost all my reception. It transmits fine just no reception.



Sorry for the stupid question bigphish.

Re: RR Spectra Receive Problem

Posted: Sun Dec 14, 2008 9:26 am
by kc7gr
One of two possibilities occurs to me.

First: The radio had receive problems (likely an issue with the front end module) before you started working on it. You may want to try a different front end from a donor radio of the same bandsplit.

Second: You created a short or open along the receive side in the process of replacing the cable assembly you describe.

Spectras, railroad or otherwise, are pretty much "alignment proof" on the receive side. They should be able to receive, at rated sensitivity, across the entire bandsplit they were designed for.

Happy tweaking.