Cobra blue face 350 with 2 2879s seems like the relay is sticking after it warms up it stays keyed up, untill power is turned off on amp. Don’t see anything like a bad cap of anything burnt could it really be the relay? I got the amp used so it never work and don’t know the history
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Cobra XL 350 staying keyed up after warm...
- Thread starter Justwantdahifiaudio
- Start date
have you changed the length of the jumper coax? i had a galaxy 350 with the blue face which i think is the clone like yours and it would do same thing. i just shortened the jumper coax and problem went away,,,
I had it in my mobile now have it on my base and tested on a dummy load this morning, amp seems to be keyed up at all time? Just power it on it starts to get warm
Is the relay stuck or do you hear it clicking when you turn the amp on and off?
I hear a relay clicking yes. when putting my finger around both relays it’s hard to tell which one is clicking.. the click sounds good but I can’t feel anything?? I would think as good as the click sounds I should feel something?
Feels like only one pill is hot?? Amp doesn’t have to be on just have hot power running to it and it’s gettig hot...
This is where I start pulling and testing parts. You can start with the realy. One of the contacts could be stuck and causing it to draw bias current and warm up the pills. The fact that only one is getting warm means one is probably bad.
Oscillation could be causing it to key up on its own. Could be due to a bad transistor, bad caps or feedback components out of tolerance. I'd check the transistors first and then decide how much the amp is worth to you.
Oscillation could be causing it to key up on its own. Could be due to a bad transistor, bad caps or feedback components out of tolerance. I'd check the transistors first and then decide how much the amp is worth to you.
You never said your jumper length - if you have a 3' or shorter jumper length it can cause an amp to stay keyed. Always use 6ft or longer if possible or use high quality coax if you have to go shorter.
That's a very bad sign. If you don't hear the relay go "click" when the power is applied, this suggest a bad 2SC2879 transistor that draws current on standby.
It appears the schematic was never released into the wild. Makes it tougher to suggest where to look.
Kinda calls for someone who knows what should be wired where to make sense of it.
Thought we had shot some pics inside the last one that visited here, but nothing turns up in the archives.
Dern!
73