SQUAWK!

[Wrench]

First post. I just got a 148 GTL, in great shape, from a trucker freind of mine.
When you key the mic, it sqeals, loudly. The squeal is trasmitted with a strong signal. and also seems come from the board. But, if the radio speaker is disconnected, it does not squeal. All lights and the meter work, and it does not squeal on PA. Where should I look? It reacts to the mic gain, with several stock mics.
Thanks.

 

[BOOTY MONSTER]

does it have talkback ? does it squeal if you have the mic gain turned all the way down ? what mic are you using and are you sure its wired correctly ? have you tried a different mic and get the same results ? front or side mic 148 ?

 

[Wrench]

does it have talkback ? does it squeal if you have the mic gain turned all the way down ? what mic are you using and are you sure its wired correctly ? have you tried a different mic and get the same results ? front or side mic 148 ?

No talkback, Stops squealing with the mic gain down, then it stops transmitting. Stock, non-amplified mic, and tried two other stock mics.
May be a diode or cap. somewhere?
It is a good looking, stock radio. Dead key with antenna is about 2 watts, swings to almost 5.

 

[Wrench]

Fixed

I found the problem. Somebody must have removed an echo or roger beep, and two gray wires were reversed. On went to the Mic, the other went to the back of the radio. It works OK, just needs a watt or so. I guess I'll change out some resistors. It has 1306 and 1307 finals, not made anymore.:thumbdown:

 

[9C1Driver]

"It has 1306 and 1307 finals,"

That does not sound right? Hmmm

Should be a 2SC2166 and a 2SC1969.

 

[Wrench]

"It has 1306 and 1307 finals,"

That does not sound right? Hmmm

Should be a 2SC2166 and a 2SC1969.

It may not sound right to you, but in the "old days," those were the ones to use, just like I recently found out MOSFETS are being used. My friend the trucker, who I got the radio from, may have had those put in as repair a while back. The radio works fine, so nothing needs to be changed.
If it ain't broke, don't fix it. If you do, it may break.