Hey guys. Hope this is the right section. I know it's obviously not an amateur radio amplifier but I'm just trying to fix it for the fun and experience I may can gain from it. What I have acquired is a 4X1446 cb amplifier. I hooked it up to my 50 amp switching Astron supply and when I key the radio it trips my supply right away. I'm keying the amp into a 50 ohm dummy load. Now I know 4 1446 transistors could draw quite a few amps but not enough to do this. I've checked all the transistors and they test good. I'm thinking I'm getting a direct short when I key the amp but where would that be? The only spot I can think I need to check would be the keying circuit. Any advice would be great. Thanks guys
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Amplifier trips 50 amp power supply
- Thread starter mattsnibbles
- Start date
That is a bit unusual. What brand is it.
Sounds obviously like a dead short. Could be the 1446's; I'd desolder/check each one and use a DVM to look for the shorted device.
Its some kind of "Apache" lol I've never heard of it and can't find anything about it online. I did unsolder each transistor already and test them but I guess it doesn't hurt to double check my work.
Try tripping the T/R relay without any drive and watch a power meter on the output. If there is any output with NO DRIVE then the amp is oscillating and running away with itself so to say. Also it could be RF interference to the switching PSU and shutting it down. Some are notorious for that.
Thanks for the advice Captain Kilowatt. Just tried as you said and no movement on my power meter. Heard the relay pick up so I guess it's not oscillating. I run a texas star on this same power supply and it doesn't affect it or cause it to shut down (unless I try to run sideband haha). Any other ideas? I'm open to anything at this point.
I have seen RF from the amps cause the power supplies shut down. Usually a bad jumper cable or stray RF going down the voltage sensing lines. Some ferrite beads and some ceramic caps fixed it right up.
Yeah - I've had it happen with too short of a jumper cable or a questionable jumper cable with a short. Amp goes crazy, peaks, and trips the circuit. I always use 6' or longer jumpers now.