magnum s9 2 questions 2030 model

[davew41]

I have gotten a Magnum s9, THE 2030 model
not much appears to be hacked inside it..
I am looking for 2 answers
1 how do I totally stop and remove the AMT

2 Where is the limiter or location of the traces to said limiter for AM
I have sideband tuned perfect on the scope to 100% modulation
AM looks like well not at all what a AM wave should look like..
I am unable to find exactly where the limiter is located via many searches ..

I have tried to provide information here as far as some basic stuff I am able to get as far as service manuals and a few other items .

This is my first S9 and it came in for repair but the chap decided to go ahead and get a new SR955 off of me instead, he said he had this s9 for many years..
I would love to get this AM wave back to a clean clear perfect 100% modulated wave on the scope instead of the sideways bluegill type wave it is producing..
Thank in advance..

 

[mrgumby]

Cb tricks has a lot of s9 info did try that site

 

[mrgumby]

http://www.cbtricks.com/radios/rflimited/magnum_s9/index.htm

 

[davew41]

Nothing I asked is on that site, as I stated I already did research

 

[TheRealPorkchop]

The talkback is built into/onto the echo board, my memory is kinda fuzzy on this but I think there’s a relay for each onboard. There is a knob, sure you know, just turn it off and then it’s...off. ??

TR32 I believe is the limiter you seek.

It’s possible you have a bad TGM and maybe that’s why you’re seeing a bad pattern on the scope. Maybe you’re seeing it because the TGM is on? I’ve had a few fail and have to be replaced, and also the Compressor.

Maybe some genius removed TR32 or clipped R249 or fooled with changing the value. I’ve seen a few of the modulation adjustment pots go bad, tried cleaning it?

 

[Robb]

TR32 is missing from the board?
ANY parts missing from the board?
Got an O-scope?
Might have to trace it thru . . .

 

[davew41]

NO parts missing, no traces underneath cut (they like to do that also to hide their hack work instead of removing or cutting the limiter I have seen them cut the trace on the bottom of the board)
Yes I have a 100mhz scope as I stated the AM wave looks like CRAP on the scope no matter what I do with the am mod pot..

 

[davew41]

The talkback is built into/onto the echo board, my memory is kinda fuzzy on this but I think there’s a relay for each onboard. There is a knob, sure you know, just turn it off and then it’s...off. ??

TR32 I believe is the limiter you seek.

It’s possible you have a bad TGM and maybe that’s why you’re seeing a bad pattern on the scope. Maybe you’re seeing it because the TGM is on? I’ve had a few fail and have to be replaced, and also the Compressor.

Maybe some genius removed TR32 or clipped R249 or fooled with changing the value. I’ve seen a few of the modulation adjustment pots go bad, tried cleaning it?

_________________
TGM in on or off does not seem to make a difference on the scope wave

Turning the echo knob off on the front of the radio and the AMT all the way down has no effect there is still a slight talkback coming through
(kind of like the last version of the cobra 200 where we had to go on board and remove a part to kill it..)

R249 in place, traces under R249 are not cut, ( they like to cut traces underneath as well to hide their hack work)
I will try to turn the MIC pot off on the echo board, thank you
and yes the am mod pot responds to adjustment

 

[davew41]

I noticed if you lower vr1 on the echo board it kills the audio as well even with echo off
So it is finding a balance between the echo VR1 and the modulation pot on board.
Very interesting how even with the ECHO switch off it still effects normal audio
Checked r249 and r239 with ohms meter the are both fine
never did find a tr32 anywhere

 

[TheRealPorkchop]

 

[TheRealPorkchop]

Do yourself a favor and remove TR32 and check it to see if it’s good or bad. Matter of fact, checking that circuit might not be the worst idea you’ll ever have. I’d suggest replacing it with a known good piece too, I’ve got some crappy “new” ones before that didn’t work in the circuit.

the audio is routed through that echo board, remove the board and you will lose your audio.

 

[TheRealPorkchop]

Also, look near the power jack, you’ll see two wires, an orange and a yellow. Unless I’m totally stupid this afternoon, those feed the board for the talkback.

 

[davew41]

Also, look near the power jack, you’ll see two wires, an orange and a yellow. Unless I’m totally stupid this afternoon, those feed the board for the talkback.

look at mine tr32 something added? or a different revision? or a hack?
my board is different no tr32 even on top its listed underneath as in the picture

 

[davew41]

Also, look near the power jack, you’ll see two wires, an orange and a yellow. Unless I’m totally stupid this afternoon, those feed the board for the talkback.

if you cut those wires you have no receive

 

[TheRealPorkchop]

Well maybe so if you leave them disconnected but what happens when you put them together, complete the circuit sans the EB?