Search results

sorry, it’s L42 not 39. So likely it’s the driver area then that has issue? And or is there something else I should look at?

L39 in my Cobra 2000 fried and looks like mode switch is toast. Unsoldered driver and seems to be ok on the meter.

Anyone have a clue if there is a viable alternative for L44 in my Cobra?? Mine is corroded and slightly damaged and causing lots of issues in the circuit. I don’t have an old radio to pull one from. Or do you know what the specs are on it (uH?)

Soooo once again there is no bias at the driver or final. Voltages all check out fine so i assume there must be a bad part up to or prior to the driver? I replaced c157 , 200 ,214, and r209. The driver also checks out fine. And I believe D50 is ok too. What else could be fault? The only...

L44 gets very warm or hot. If I move it at all it will cool down again. Couldn’t find that anywhere else.

No I run it off an external supply.

I love your optimism!! Thank you. I just know enough to be dangerous so that's what the frustration is. I agree with Handy Andy, I believe there is still something not right in the driver/final area. I have replaced basically every component between the predriver and L38 (at least once). I...

Yeah it’s a mess and I’ve been working on this in and off for 6 months. Probably gonna cut my losses with it. I don’t think it’s worth my time anymore. I’ve spent so much time and money on it and have basically gotten nowhere.

So the final was blown after testing it. I put in a new one and now have normal voltage readings at both the driver and final. But there was still no power output. In regards to L38, the one in there did not look right.. So I pulled one from an old junk radio and put that in. Now I was getting...

So there was a bad solder connection at the AM regulator. I restored that and now all voltages at the final and driver are normal but there is no bias reading at the final at all and still no TX. Like I mentioned before, if I put a volt meter on the hot side of D49 it shows 1.2 volts and .67...

Well I am back. Again there is no Tx power. There is the expected 0.7 into the driver from C157. But on AM Tx the center leg is only showing 0.32 volts. On SSB the TX Volt is 13 volts. And it is 13 volts at the center leg on RX both modes I don’t think D50 is bad as I’ve swapped it before...

Maybe dumb question, which 2 legs do I use? Does it matter? I have a few like this so once I get the main problem resolved I’ll go back and revisit this. Thanks.

Great thank you!! Also what is the value of that green cap over near the right edge?

Do you happen to have a good closeup of the solder side of the board at the driver? Like taken right over the top of that area to see the traces.

LOL! Thanks for the help so far. I will get back to you once I get the new driver in (should have it in tomorrow or Friday).

Yeah I was poking around there after I posted. I think I smoked the driver again. WTF!!!!! I need to get another one and hope that's all I did. Right now from checking, everything else appears to be ok. SOOOOOO tired of this. Anyone want to buy a parts only Cobra 2K? LOL!!

Sooooo here is something weird. I unsoldered that base leg. There is 0.7 volts at the pad which is what it should be according to Sam’s. But while I was putting my VOM probe on the base pad while it was keyed up, the probe slipped and for a second it bridged between the collector and the...

I’ll try anything. Thanks.

So frustrating. I don’t think (i hope not) it’s the driver as I’ve replaced it a couple of times thinking it was bad. I don’t see any reason it would be toast again at this point but who knows. guess I will Continue to probe away and see if I stumble on that needle. thanks.