Having trouble with cobra 148gtl dx mk2 it sound very bad on sideband but is its ok on receive sideband am and fm but on transmit on sideband it sound very rough and not very nice to listen to but it sounds ok on am and fm. I have replaced the balance modulator AN612 and tried a new mike but this did not help. So can any one help by telling what to try next, I have access to some test equipment at work.
The Tinker.
Cobra 148gtl dx bad transmit on sideband.
Cobra 148gtl dx bad transmit on sideband
Check to see if the screws that hold the PCB to the chassis tight, if ok try replacing C236, 237, 238, 239 and 271, C236 and 237 are 10nF at 50 Volt Ceramic and the rest are 47nF at 50 Volt Ceramic, they are fitted between chassis ground and chassis earth around the chassis PCB screws holes. It could be the SSB filter FL3 (10M4D) I have had this go faulted but only in TX, but replace the low-priced items first all the capacitors should be less than two quid. Hope this helps, let us know how you get on.
Rick.
Rick.
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Anonymous
Cobra 148 bad transmit on sideband. Thanks Rick...
You was 100% right lose screws at the rear of the pcb and i put in all new capacitors; that Uniden export manual came in use after all that time; the rig sound like in was new not bad for 28 year old rig. This is only the second time it has been repaired in all that time and it is used ever day on the way to work and home and most weekends up on the hills shouting CQ.
Thanks Rick for your help.
P.S. I how know what 0.01 and 0.047 capacitors are.
The Tinker
Thanks Rick for your help.
P.S. I how know what 0.01 and 0.047 capacitors are.
The Tinker
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frogman296
- Heavy User
- Posts: 228
- Joined: Monday 12th Nov 2007, 0:47
- Location: canada
Not the same radio.
The Cobra 148 GTL-DX is not the same as a 148 GTL, they are to total different radios.
I think you would be better off starting a new post, and when you post in is always best to put some info in the Post Subject line, as this make it easy to keep up with the Post.
I think you would be better off starting a new post, and when you post in is always best to put some info in the Post Subject line, as this make it easy to keep up with the Post.
Rick.