Magnum S-9/SSB Receiver Distortion

[Robb]

A local operator asked me to look at his S-9 radio.
On SSB modes, the receiver has a lot of distortion/overload.
AM is fine; TX on SSB is OK too.

Are there any tips or clues from the gurus here?
Already checked the service bulletins and nothing there.

http://www.cbtricks.com/radios/rflimited/tech_notes/graphics/s9_tip.pdf
http://www.cbtricks.com/radios/rflimited/magnum_s9/graphics/magnum_s9_sch.pdf

The receiver in this radio is similar to the 3600 chassis - BTW.

 

[Robb]

Guess the gurus aren't up to the question; or they didn't see this post!

 

[9C1Driver]

With a Magnum radio I usually wrap it 3x in bubble wrap, put it in a box with foam peanuts, and ship it to The Radio Shop in CA or Bob's CB in PA.

 

[loosecannon]

these are just guesses here. it could be an AGC problem. you might try to find a block diagram for any of the magnum SSB radios and see if that leads you to the right place.

also check the soldering on FL3, L13, and L14, and other parts in the surrounding area.

there is a VR in there that is an internal RF gain, its VR22, but i dont know if its active on SSB or if its just for am and fm. it could have been set too high.

this is a strange problem,
LC

 

[9C1Driver]

these are just guesses here. it could be an AGC problem. you might try to find a block diagram for any of the magnum SSB radios and see if that leads you to the right place.

also check the soldering on FL3, L13, and L14, and other parts in the surrounding area.

there is a VR in there that is an internal RF gain, its VR22, but i dont know if its active on SSB or if its just for am and fm. it could have been set too high.

this is a strange problem,
LC

Glad to see your thoughts on this Loosecannon, you always have good straight foreward technical advice.