Cobra 148GTL RF gain not working

[Seawolf18]

I am having more problems with my 148GTL manufacture date 1989 made in phillapens(sp?). The RF gain is not working. If you turn the knob counter or clockwise there is no difference in the recieve. Basically its stuck on full clockwise or full recieve. I am thinking the knob is bad, but how does a guy check it?

 

[nomadradio]

Hmmm. Key the mike, with a wattmeter in line, and the radio set to AM. Crank that RF Gain knob, and see if the wattmeter does anything.

If it's been hijacked as a carrier control, that would explain it.

73

 

[TonyV225]

Im with nomad on that one thats exactly what I was thinking I am also willing to bet its a variable power.

 

[Switch Kit]

I hate that when that happens (-: .....sure would have been nice of them to let me know from the get go ? .....even if he doesn't have a watt meter ..the s-meter on the radio should move from right to left all the same when keyed up on AM and turning the rf-gain knob (this to should let him know that he might just have varible power as well) ......Hmmm ? 1989 Phillipines huh ? Nice radio Seawolf !!! Welcome to the Forum

 

[Seawolf18]

ok, i hooked up a watt meter and did what u suggested. No change in the carrier power. However, if you turn the knob full counter clockwise and wiggle it, the static cuts in and out monentarly(sp?).

 

[nomadradio]

Hmmm. Sounds more and more like a bum control. Any sign that somebody bumped his knee on that knob, like a bent shaft, maybe?

Don't have a handy pic, but the quick test for this is to turn the control full to the right, and use the tip of a small screwdriver to bridge the center lug of the pot to the clockwise lug.

If the control has gone bad, this will get you your noise level back until the screwdriver tip is removed. It can be important to turn the knob full clockwise before doing this. Bridging the wrong end-lug of the control to center can damage the control in some radios. Probably not this one, but it's never a bad idea to use care.

73