Cobra 2000 gtl transmmit problem

[badcordoba]

Hello,

I am new here and would like to say that there is alot of great information on here. I am having a problem with my Cobra 2000gtl. I can only get 4 watts maximum power according to my Dosy test center. The radio was supposedly redone (not) and I noticed that the 1969 final is not there. There is another final it it's place. It was doing more than that when I bought it, but now only 4 watts. Is there anything I can test or look for to find the problem? I am decent with a dvom and I do have a schematic for the radio and am an excellent solderer.

It does have a variable power pot. on the back that changes the deadkey from 1/2 watt with 4 watt swing to 4 watt with no swing. This radio was supposed to do 20-25 watts. I have tried the tuning coils with no improvement. Is the final bad or is the driver bad?

I do not have the Sams for the radio, unfortunately. I would appreciate any information you guys may have to offer.

Thanks.

 

[Moleculo]

It sounds like a driver or final issue, but obviously it's hard to tell from "over the internet". What final is in there since it's not the 2sc1969?

 

[Switch Kit]

2312 ? Sorry to hear about your 2000 if the radio is in good condition and everything basically works as it should ? It might be best for you to find a good radio man to go through it for you and bring it back up to snuff. There slowly but surely becoming harder to come by and there decent radios for what they are.

Your right , it should do at least 20 watts AM/SSB .

 

[freecell]

make sure the driver is a 2SC2166 and put a 2SC1969 in the final section and start all over again. with first run oem components and a proper alignment you should be seeing 18 - 20W on am and 25 - 30W on ssb. don't forget to remove the variable carrier crap.

 

[badcordoba]

final and driver numbers

Thanks guys, it has the OE 2166 driver and a 2312 final. I do not know why the 1969 was removed (probably to steal it, dunno). Where are the adjustments for the am power? I only see a couple of coils, but do not want to turn anything with out knowing which is the right one.

Thanks for the input.

 

[badcordoba]

One more note.

I just figured out that the "variable power" knob that is on the back of the radio was installed in place of vr10. It changes dead key as well as max output. Is that done wrong? If so, where should it be installed. I do run a little Shooting Star 225 inline. On low it deadkeys .5 watts and swings about 4.5. With the knob all the way open, it deadkeys 4 and swings 8 watts. That does not sound like it is right. I thought the "knob" should change dead key but not swing. Maybe I am wrong, I do not know. Also r196 is cut as well.

It has been soooooo long since I messed with radios, I cannot remember. Some things are starting to come back to me, though.

Thanks again.

 

[badcordoba]

I did find the proper coils to turn elsewhere on this sight on another post, very helpful, and could not get anymore than 8 watts maximum. I also notices that the wire going to the tp7 has been removed and soldered to jp1. What is the purpose of that? I did check the driver bias and it is right at 25 ma.

I do not know how the check the final bias since the wire has been relocated.

 

[hotrod]

I just figured out that the "variable power" knob that is on the back of the radio was installed in place of vr10. It changes dead key as well as max output. Is that done wrong? If so, where should it be installed. I do run a little Shooting Star 225 inline. On low it deadkeys .5 watts and swings about 4.5. With the knob all the way open, it deadkeys 4 and swings 8 watts. That does not sound like it is right. I thought the "knob" should change dead key but not swing. Maybe I am wrong, I do not know. Also r196 is cut as well.

It has been soooooo long since I messed with radios, I cannot remember. Some things are starting to come back to me, though.

Thanks again.

repai r196 i believe thats trhe limiter.theres a vr to adjust
aUDIO no need to clip anything.with the 225 inline adjust radio for about 2watt dk
this should be ok.if there is a final/transistor blown ya wont get anymore power
out of it.id check these first.then tune the radio the way it should be.