Spectra audio clipping and MDC 1200 problem

paemtp897 · Post by **paemtp897** » Thu Mar 02, 2006 5:57 pm

I purchased a used Spectra High Power VHF with an A-9 head and have had several problems with it. We noticed 2 things right away. As a result our local radio guy checked it out and find that the EPROM was bad. He replaced the EPROM and reloaded the Code plug. These issue are still happing though. First and most importantly we have audio clipping a lot. This happens in and out of scan, PL's on or off, and even when it's connected to a different control head, antenna, and wiring. Also the Rx light goes out as well. Does anyone one have any Idea's? We were thinking it could be the audio ship or synthesizer. Also we keep getting a data burst being set out at the same time the MDC ID is being sent out. Is this a lost cause?

jackhackett · Post by **jackhackett** » Thu Mar 02, 2006 7:27 pm

the first thing to suspect in a spectra is bad capacitors, this has been discussed many times here, you should be able to find the previous discussions with a forum search. basically all of the electrolytic capacitors go bad and need to be replaced, and they may have also leaked and damaged the circuit boards. some of these caps are in the audio circuit, so that could well be the cause of your problem.

not sure what you mean exactly by a data burst going out with the mdc, but I'm going to take a stab in the dark and suggest checking to see if someone has installed an add-on ID module to send GESTAR.

paemtp897 · Post by **paemtp897** » Thu Mar 02, 2006 8:00 pm

It does sound like GESTAR, but the RSS has no option for it. And before the Code Plug went bad it did not send it with the MDC 1200.

jackhackett · Post by **jackhackett** » Fri Mar 03, 2006 6:30 am

Are you talking about hearing the data burst through the radio's speaker, or is it being transmitted by the radio? If it's transmitted, try turning off MDC and see if it's stil there, if it is it's probably an add on board. Spectra's don't do GESTAR so sometimes an encoder module was added to them, if they've got one and you also enable MDC you'll get both formats at the same time.