With SSB you have to put audio on the carrier you cant just key the microphone and expect it to output a signal unless you talk into the microphone at the same time this is how SSB works.
So if you talk and the meter starts to move then its ok, if you talk or whistle and nothing moves then the circuit on the SSB side of the unit is faulty.

Been a long time since my first post, but it's been moving all over the place.
First to the French Magnum certified repairman, confirmed the instability issue, not able to fix it. Then I had to send it to Holland to Avera, which is the European rep. for Magnum. Unable to repair too, so they're proposed me an exchange... a long way to get a working set.
Now new worry, audio peps not always there, depending upon temp. (radio's in the car), the mic either works correctly, or it 's difficult to get some power out of it ...thinking about trying another mike, will update the post once done,
73 to all
Fred 14 FAT 138

YOu need to check the finals on the sidebad side. Sounds like they are probably bad.
I hope this has helped.
Ed Meshechek ( Radio Man )
NC Electronics
PO Box 1696
414 6th St
Mills, Wyoming
82644
307-266-4675
[email protected]