Squealing 959

[B C]

I have a Galaxy DX959 that for some reason does not like the Firestick FS4BLK its connected to. The match is 1:1 on channel 1 and 1.3:1 on 40. The 959 puts out a RF squeal on the air when keyed. If I swap in my President Ronald it works just fine.
It's not an audible squeal in the car, just over the air. If I turn down the mic gain on the radio the squeal changes tone and if turned low enough it will go away but then there is "0" modulation.
Any suggestions or miraculous cures?

B C

[295 antenna]

sounds like a grounding issue. make sure the 959 is grounded metal the metal on the radio. i use a ground wire or strap to one of the cover screws.

[B C]

Thank you 295, I'll give that a try tomorrow, I had to walk away from it today as I was getting frustrated.

[Bluerunner]

Does it just squeal with the engine running or even with the engine, dome lights, AM/FM radio and open door, seat belt buzzers off too ?

[B C]

It squeals with nothing else on the car turned on.

[Bluerunner]

I agree the first step would be to ground the radio case to the car chassis, if you can find any metal under all the plastic nowadays.

Is there a talk-back mod on the radio?

Can you key it up with no mic maybe using a paper clip across the proper pins.
Need to know what you are doing to avoid damage, but could determine if the mic & wiring is the cause.

After that, I find that very loud swearing and a few beers often makes you feel better about it even if it doesn't fix the problem.

[295 antenna]

I agree the first step would be to ground the radio case to the car chassis, if you can find any metal under all the plastic nowadays.

Is there a talk-back mod on the radio?

Can you key it up with no mic maybe using a paper clip across the proper pins.
Need to know what you are doing to avoid damage, but could determine if the mic & wiring is the cause.

After that, I find that very loud swearing and a few beers often makes you feel better about it even if it doesn't fix the problem.

I concur LOL

[MDYoungblood]

I am guessing you are hearing the feedback when you use the talkback feature on the radios.
Yes, grounding will help, bonding the antenna bracket/mount will also help but I'd lose the FireStik. Check the mount and coax, if it is a FireRing coax, check to see if the insulation on the ring is broken.
Sounds like a CMC problem, you don't hear it on the President Ronald because it has slightly better shielding.

3's

Greg

[B C]

I also concur with Bluerunner, it didn't work but afterward I didn't care as much.
I have the talkback turned off, but I'm seeing the squeal on my wattmeter and my MFJ "SWR/Matchbox. I tried talking on it but the guys on the other end say it's just squealing.
I'm going to look for a suitable ground for the radio, as for the antenna, it is on a 5" MFJ magnet mount and it seems to work great, I can talk to Alexandria Ky. from here on it (23 miles) using the President Ronald.
I'll report back if I have success and if I don't …..when I get done swearing and drinking I'll report back for some more ideas.

B C

[Bluerunner]

Do you have an amplified mic on it? Is it the original equipment mic?

[B C]

Yes, I do run a power mic, but I have also tried it with the stock mic. and got the same result.
I'm still working on it.

[Bluerunner]

Does it squeal on the base station antenna or just in the car?

[B C]

Just the car. I have tried other radios in the car with the same antenna and they work fine.

[Bluerunner]

Do you have enough extra coax to close wrap 5 turns around a 4" dia PVC pipe form to make a CMC choke?

Better if you can put it somewhere that it isn't laying on or very close to metal. Might be worth the trouble to add a longer coax jumper if the coax you have is too short to make the choke. you will need about 6' of coax to make the choke with a little tail and connectors on both ends.

A shorted tuned 1/4 wave stub may work too. The stub and choke coil have solved a lot of enigmas for me.

[B C]

I tried the CMC Choke, with no apparent change, so...….I uncoiled it and moved on to the next guess.

[MDYoungblood]

Just the car. I have tried other radios in the car with the same antenna and they work fine.

Since this is the case I would look at maybe getting the radio realigned, that stray RF is coming from somewhere.

3's

Greg

[B C]

I tend to agree with you, if I get time tomorrow I'm going to try a couple of little tricks, just to "fire for effect". I'll let you know what I find, if anything.

[Bluerunner]

Where is the power to it coming from?
What kind of car is it?

Some cars never actually turn everything off, always some little computer in standby waiting for a command, or Lojack, Onstar, or some GPS thing.

Digital readouts and display screens often make a bunch of noise.
Bring a little transistor AM radio (I guess they still make them?) near any digital display in the car or in the house and tune around the dial. Good way to find phantom noise sources.

[B C]

I got up bright and early this morning (4am) with an idea in my head. I remembered years ago either Turner or Astatic addressed this problem in one of their manuals. There was two solutions, one was putting 1 or 2 .001 disc capacitors from white to ground, another was to put a resistor or a choke inline in the white wire. I had a small choke from Radio Shack that I bought years ago to make a "invisible fence" wire detector for my neighbor. There was 2 in the pack so I still had one. I put it inline in the white wire and BINGO.....the squeal was gone!!
Thanks for the help and suggestions with this problem ,they were the catalyst to keep my thoughts going on this.

B C

[MD115]

Just slap that..... Radio. And try to add a noise filter, I Mean from the current Just before you conect your radio. Maybe could help, and if you are going to say that with your presidente radio doesent hapoend, Maybe has better componentes inthe current input than the galaxy. By the way I have a 959, well actually 2. Hope it helps

[B C]

Acuario, I did slap the 959 a few times, maybe THAT'S what fixed it. Either way it's working and very happy again.

B C

[MDYoungblood]

Acuario, I did slap the 959 a few times, maybe THAT'S what fixed it. Either way it's working and very happy again.

B C

Really?? In that case there might be a loose board screw or 2, open the speaker side and check the chassis screws but don't over tighten them. I'd pop the solder side of the case as well, if you read Beachbum24's topic, he found some joints that weren't soldered at all.

3's

Greg

[B C]

Greg, I was only kidding, but I was serious about the cussing and the beer! LOL

[MDYoungblood]

Cool,, but you'd never know. I do know a good smack (by their mom) kept my daughters inline, might work on a radio,, lol.
BTW,, the Beach statement was true.
3's

Greg