Magnum Omegaforce s45HP rf power adjustment inop

[Champo]

I have a MAGNUM Omegaforce s45HP that I acquired a while back that works perfectly fine except for two issues. The first is no modulation with the stock mic. I'm going to ignore this issue for the time being until I can verify the mic works. The radio works fine with the cobra mic connector.

The bigger problem is the rf power adjustment doesn't work in AM. It's supposed to adjust the carrier level (1-40 watts) but it doesn't. The carrier is stuck at 20 watts. It does work in FM and SSB. Initially I found that the wire with the red arrow in the image had come loose from the potentiometer. I tacked that back in place but there was no change. I verified the potentiometer is working (the resistance changes as it is adjusted) so I'm not sure where/why the issue is occurring. Any help on where to look would be greatly appreciated. Thanks!

 

[9C1Driver]

Magmun Omegaforce S45HP Service Manual

The above link is all I can find right now. I have one and they are great radio's. Just several thoughts, the variable power is not supposed to give you a dead key from 1-40 watts. 40 watts is way too much. I think mine is set for a max AM dead key of 14 watts. I would run it at a conservative wattage level so you don't blow that 7530 mosfet final. They are no longer made and very hard to find.

 

[Champo]

Magmun Omegaforce S45HP Service Manual

The above link is all I can find right now. I have one and they are great radio's. Just several thoughts, the variable power is not supposed to give you a dead key from 1-40 watts. 40 watts is way too much. I think mine is set for a max AM dead key of 14 watts. I would run it at a conservative wattage level so you don't blow that 7530 mosfet final. They are no longer made and very hard to find.

Thank you. Yeah unfortunately I haven't had luck with the cb tricks stuff. I've been working from that. You're right about the carrier. I pulled those numbers from some web page. The rf power adjustment works in FM (1-18 watts) and SSB but AM is stuck at 22 watts, which as you said, is 7 watts higher than is recommended (max of 15 watts, as you said, in Magnum's literature). That's where I'm stuck. The wiring diagram shows the feed to the potentiometer for FM and SSB but it doesn't show it for AM. The alignment instructions also mention the pots for FM and SSB output but unfortunately not for AM. I was going to try adjusting the pot to see if I could at least measure an output change.

 

[9C1Driver]

The alignment procedures are on cb tricks for the regular S45. Most of it should be the same except for the power levels. Good luck.

 

[Champo]

The alignment procedures are on cb tricks for the regular S45. Most of it should be the same except for the power levels. Good luck.

Yeah the problem is that all it says in the alignment instructions is "Check AM power to attain between 6-12W rf power." For FM it calls out adjustment RV117 and SSB RV116 to adjust power out. No call out for AM. Unless I missed something they are of no help.

 

[undertaker]

Call superior cb they work on magnums ..