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Cobra cam 89 question cause tranformer is getting hot

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Grump
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Cobra cam 89 question cause tranformer is getting hot

#209987

Post by Grump »

I have a cobra cam 89 and the tranformer tf 080 is getting hot wether it is plugged into the wall or to a 12 volt system radio shows about a half watt on my cheap meter and a resistor next to it is showing signs of being hot like bubbles on the surface any help would be appreciated. Everything works on it other than that.
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Grump
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#210020

Post by Grump »

I searched a little further it is the af output transformer t-10 any help would be greatly appreciated
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'Doc

#210026

Post by 'Doc »

An audio transformer is getting hot? My first suspicion is that there's a defect of some kind. Either in the transformer it's self, or it's associated circuit, or it's having the 'snot' driven out of it. That's just not all that common, sort of. Having no idea what's been done to the radio, I'm not even going to try to guess what the problem is. I think I'd take it to someone who has the equipment to check it.
- 'Doc
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Grump
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#210042

Post by Grump »

Doc I looked at everything and nothing seems to be messed with could a resistor getting hot on that circut cause the transformer to get hot
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Grump
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#210228

Post by Grump »

I did some more looking and I seen that the two diodes on power supply have been cut and then resoldered then I did a voltage test on the main board and it has 11.3 volts going to main board and the board says 9 volts, has someone volted up the board to get more watts and is their away to fix it I spent almost two hours looking and nothing else looks like it has been messed with also I was wrong the transformer is getting warm but it is the resistor next to it that is smoking they are inline so I'm thinking the resistor is bad causing the transformer to get warm. I like this radio would like to get it up and running. The nearest shop to me is 40 miles away and won't go to him cause he is a hack and a bad person won't get in to it any farther. I also don't think the radio is worth trying to pack it up and ship it to get it fixed so I'm trying to do it myself.
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'Doc

#210386

Post by 'Doc »

I don't have a solution for you. I can say that resisters are not meant to get that hot, so something is wrong there. A volt or two 'extra' doesn't necessarily mean those diodes are the wrong ones. But then I'm not familiar with that radio, so take all this with a grain of salt (maybe 'ExLax?). Good luck.
- 'Doc
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Grump
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Re: Cobra cam 89 question cause tranformer is getting hot

#221369

Post by Grump »

Well I got another radio that is the same radio only it does nothing. turns on (lights) no tx no rx would it be worth me puling out the af transformer and resistor next to it and put in old radio
327 from the flatland working the antique radios
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'Doc

Re: Cobra cam 89 question cause tranformer is getting hot

#221424

Post by 'Doc »

Grump,
Would it be worth the effort? I don't know, that's up to you. It might solve the problem, but it also may not. That's the problem with part substitution, finding which part really needs substituting. It also assumes that the parts you will be replacing the other parts with are good to start with. I ain't biting on that one! :)
- 'Doc
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Grump
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Re: Cobra cam 89 question cause tranformer is getting hot

#221518

Post by Grump »

I know doc but Since everything else on the radio seems to work I'm hoping that maybe the transformer or resistor went bad. I've set both radios side by side and cant see anything else that could be causing this. So I was thinking if it the transformer or resistor that is bad then I would have one radio and one extra power supply with extra parts
327 from the flatland working the antique radios
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