Cobra 148GTL now... NO MODULATION

[Gunner357]

I have a 4 watt dead key absolutely no modulation....New Mic and tried another.... all knobs are were they should be HELP please.

[MDYoungblood]

Plug a speaker into the PA jack, turn the PA switch on and see if you have audio, if not then it’s most likely the audio transistor.

3’s

Greg

[Gunner357]

thank you i have to get a speaker........

[Gunner357]

ok just to recap.....key mic up meter shows dead key of 4 watts talk into mic nothing

i got a speaker, turned on pa dx audio comes threw when i key it up ya here it crackle then static talk nothing.....

im going to get another mic just to be safe this mic has 5 pins i don't have another one available right now

oh btw the wattage shows on my swr ext meter it does not show on the radios meter

[Gunner357]

I went ahead and tested the finals and the c1969 does not come up with the right values so I went ahead and got me 2 of each coming they have the original look so hopefully not fakes but gotta wait till the 21st so.... ant thoughts guys?

Also these schematics was looking for a D44 diode for 3 hours last night,,, one schematic shows it right next to D43 that is next to IC4 well theres no D44 next to D43 so I got another PC board top view and bottom view schematic It shows NO D44 any where on that board yet everyone is saying "Its your D44 Diode" What the ***** ......anyway I hope the finals are it in a way.....

does this look like a potential bad solder joint?



UPDATE:
I got it working..... After posting that picture above I re-soldered that joint... and others that looked abnormal in the audio area.... I also re-soldered the finals .....I didn't like the looks of those either.... plugged it in and with the exception of the S meter barely moving on TX AM it works now, I had a friend talk in the Cobra and I went out to truck and it pegged my S meter so that's it Ill take it to the CB shop so they can Align and verify....... there's a 25 y/o radio back in action .....

I wasn't real happy with the modulation with a regular mic so i adjusted VR5 and nothing so i did something I really didn't want to do and clipped R131 and no major change, so I guess unless when I go get it aligned he cant boost it , ill just keep the power mic on it...

[Gunner357]

I was reading felt guilty ended up fixing the diode I clipped ..... Im a hacker to a point......

[443 Arizona]

hack,wack,smack,jack, i do it all to the radio's. that way i know they need fix'in

[Gunner357]

gonna be starting over see why my mic circuit is weak

[Gunner357]

Finals are in so is some special soldering stuff i need so Im off again on the Cobra

[Gunner357]

The Mofset change out didnt do anything any other ideas on the Low modulation in the Cobra? must use a power mic reg does not cut it......

[1iwilly]

by the way vr5 is for the trasmit frequency adjustment i beleive you said you clip r131 and still audio is low posible a bad or dirty mic gain pot

[Gunner357]

by the way vr5 is for the trasmit frequency adjustment i beleive you said you clip r131 and still audio is low posible a bad or dirty mic gain pot

I clipped R131 no difference so I fixed that the pot its possible because I turned that also no changes

[Gunner357]

by the way vr5 is for the trasmit frequency adjustment i beleive you said you clip r131 and still audio is low posible a bad or dirty mic gain pot

TYPO VR7

[Gunner357]

well after how many years I finally fixed the Cobra 148GTL It has modulation Boy does it!!! No hacks or mods and I can use a 636 on it now instead of a power mic... Its so loud I have to turn down the dynamic to 25%... and its verified I drove down the road a ways 5 miles and called my STEP son and he waved back and it was loud.... I aligned the TX side just because of the messing around every looks good...... And again the best thing is no HACKS or MODS The Cure was I re-soldered some resistors and solder joints on the mini mic circuit board on the side .... now i can pay more attention to my HAM tickets and a new ALL band HAM radio......