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Stitches
Posted on Sunday, March 30, 2003 - 5:18 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

My Cobra 2000GTL, Date of MFG.12-1991
(Philippines) works great on AM TX & RX, both TX & RX on SSB, But when warmed up for about an hour or so it won't TX on AM or SSB, but it will RX on AM & SSB. Tried PA and it will RX Signals from AM & SSB in PA position but PA does work when keyed up. I'm running a Cobra #CA-72 Mic., tried other Mic's. but same results. Any idea as to why this is happening?
Also....when this radio is turned off and I try it the next day, this same problem comes back. Thank you for your time.
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Stitches
Posted on Wednesday, April 02, 2003 - 6:52 am:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

Ok......Anyone else have any idea as to what might cause this?
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307
Posted on Wednesday, April 02, 2003 - 9:00 am:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

Have you tried to adjust the VFO ever so slightly?

307
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Stitches
Posted on Wednesday, April 02, 2003 - 11:37 am:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

No sir, I didn't even think about doing that. I'll give it a try and see, if by chance this doesn't work, would this componet be ready for an R/R?
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307
Posted on Thursday, April 03, 2003 - 7:29 am:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

Nope....It would be something else I am sure...

307
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Stitches
Posted on Thursday, April 03, 2003 - 7:11 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

Ok, Let me know what you think it could also be so I'll be ready to check it out too 307. Thanks
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Adshar64
Posted on Sunday, May 18, 2003 - 2:00 am:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

Dont you mean the vco tuning coil? sounds like your trouble.

cheers 389
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Brownsmillsch18
New member
Username: Brownsmillsch18

Post Number: 4
Registered: 2-2004
Posted on Thursday, June 17, 2004 - 10:08 am:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

Could be the driver/final transistors in the tx amp stage heating up. One way to diagnose it is to use a can of "freeze" spray , and spray on the driver and final transistors while transmitting. Do this and see if operation is restored. I don't understand why you guys are eluding to the VCO, he would lose RX if that was misaligned. He says he has RX.
Good luck

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