TK-790H Power shut down upon mic keyup

[707Lineman]

My local FD I volunteer for pulled our TK-790H Radio with remote head and speaker out of an engine we are selling. We went and installed the complete unit in our new truck we bought. Radio was working fine before the move. Now when we key up the mic to transmit, the whole radio shuts down. I've checked all the grounds ( In the remote head, in the radio, antenna, and chassis ground) It does not blow the 30A inline fuse. Mic is hooked up, antenna was continuity tested with a meter. Radio when powered on, recieves transmissions on several different channels as expected. Just powers down when keyed up

Thanks for any help with this issue

 

[SB-Wi]

Sounds like a voltage drop. Check when trying to transmit.

 

[707Lineman]

It's weird, We have a buss strip in the radio box. It has 6 separate 10A connections. The other radio a Motorola is connected to output 1 with the kenwood being connected to output 2. Both radios are powered on at the same time (different freq, but not used at the same time

 

[w2xq]

Wirelessly posted (Moto Droid Bionic: Mozilla/5.0 (Linux; U; Android 2.2; en-us; UPC300-2.2 Build/FRF91) AppleWebKit/533.1 (KHTML, like Gecko) Version/4.0 Mobile Safari/533.1)

Does the radio have circuitry to protect the transmitter if the radio doesn't like the antenna match? SWR?

 

[Essexscan]

is it possible transmit was disabled over the air from HQ? it does sound like a voltage drop since the whole radio shuts down. Does it do it with the vehicle running? It's DMM time to check voltage

 

[Thunderknight]

Try it with a dummy load - that symptom may also be high SWR.

 

[707Lineman]

Checked the SWR, Suspected an issue with voltage drop. Its hooked into a 10A Circuit, Manual says it needs to be on a 30A Circuit. Totally our fault. Will report back when Its connected correctly. Thanks for the help

 

[707Lineman]

Problem Solved!

Didn't check the radio manual, It needed to be on a 30A circuit. Thanks for all the help

 

[mrweather]

I was going to say, 10A won't cut it for the 790H especially if it's putting out the full 110 watts.

 

[BCLG316]

Exact same thing happened to me the other day. Don't feel bad I was baffled as well. I put a new connector to the power source and it works fine now. No clue why it started cause it has been hooked up for years in my truck but it is working again so check your power connector.