Cobra 2000 gtl issue

[loosecannon]

dam low_boy you go straight for the jugular

Low_boy has seen all this play out before.
LC

 

[kaos513]

Thought was fixed but now I lost TX complete now

 

[kaos513]

I did tried everything Andy posted I appreciate his help and everybodies help as well on here, but I went to key up today and TX died on me so I'm back to the drawing board , but now I get my volatges at the final and driver but TX is gone

 

[1iwilly]

the few times mine does that i go back and forth on the am lsb USB switch and it comes back or at times my mike plug is loose

 

[Handy Andy]

I did tried everything Andy posted I appreciate his help and everybodies help as well on here, but I went to key up today and TX died on me so I'm back to the drawing board , but now I get my volatges at the final and driver but TX is gone

This is closer to the why I posted the clarification.

I've seen so many times perfectly good 142's, 148's - Grants, Washington's and even 2000's that use the "manual MODE" switch that although is physical - is the reason why the radio wound up in the shop - those switches simply burn out - open up like a fuse - age and for example - abuse - from people volting them. When the Final blows up - takes the switch out with it.

When the inboard (internal power supply) was bypassed and they ran in - in some cases - 20 amps - you can imagine the results - it's a lot like an insurance claim game. "I didn't know" - now - what was once a heirloom and collectors item, is now nothing more than scrap.

I'd rather shoot for the moon and miss, than to neglect a simple step that if not followed - you'll never get the jalopy off the ground.

I can only work with information that is presented in the post and thread - don't and didn't ever, want to badger a poster for more information than what we can use.

 

[kaos513]

I get full recieve on my radio with no issue

 

[Handy Andy]

So what did you do?

No TX but do you have TX light?

You said SSB works, does it still - or no TX at all?

Review the work done - would like to know what work was done so we can guide you.

 

[kaos513]

I put it to the side will continue in or sell for parts not sure yet

 

[HavaV10]

If you're lucky, the problem lies with TR41. Factory type is 2SC1419. It's bolted to the heat sink at the right-rear corner of the main circuit board. If you have about 13 Volts DC on the metal tab of TR41, and nothing on the metal tab of either driver or final transistor, TR41 is probably the culprit. We have been using a part with a higher current rating than stock, mostly because the price difference is too small to sweat. A long list of possible subs is out there, but we use TIP41, with any suffix letter, A, B, or C.

Back in the day, we'd send people to RatShack for the TIP3055 transistor that they stocked for decades. Now it's fleabay.

73

what about NTE 152 is it a good replacement for the 2SC1419. I lost AM transmit on my Cobra 2000 SSB works fine.

 

[nomadradio]

NTE152 is a legit replacement, pretty sure. Haven't used their parts much at all. Stocking the original types is just cheaper when you're buying ten or more at a time. Just be sure to also replace TR42, the 2SC945 transistor that drives it. We learned to do that as cheap insurance. When TR41 fails, TR42 can get hammered or weakened.

Make sure to use heat sink compound on both faces of the mica insulating washer. It's important.

73

 

[HavaV10]

NTE152 is a legit replacement, pretty sure. Haven't used their parts much at all. Stocking the original types is just cheaper when you're buying ten or more at a time. Just be sure to also replace TR42, the 2SC945 transistor that drives it. We learned to do that as cheap insurance. When TR41 fails, TR42 can get hammered or weakened.

Make sure to use heat sink compound on both faces of the mica insulating washer. It's important.

73

thank you my friend for the suggestion of replacing as TR42. I think I have some C945's on hand.