Sharp GF-9494 FM stereo issue

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jimmyjimmy19702010

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May 5, 2012
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Hi Guys,

Just a quick question to those who are in the know. I recently received a solid GF-9494 from Scotty and I have an issue with the FM stereo light. It's difficult to get the stereo light to turn on. It does stay on once you get stereo though.

I understand there is an adjustable resistor that can be tweaked to improve things.

I have a schematic from the net but it's pretty difficult to know which one to adjust. Is it the -semi adjustable resistor R22?

Any advice is welcome,

James.... :-)

View attachment 2011
 

baddboybill

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Jul 14, 2009
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Usually but not in all cases the adjustable resistor is the one closest to the tuner capacitor on board. Post pic of tuner scheme and/or tuner board and that might help ;-)
 

jimmyjimmy19702010

Member (SA)
May 5, 2012
3,578
26
38
Sunny Brisbane, Australia
baddboybill said:
Usually but not in all cases the adjustable resistor is the one closest to the tuner capacitor on board. Post pic of tuner scheme and/or tuner board and that might help ;-)
I'll pull it down in the next couple of days for a pic.

The VU signal strength meter is almost at max on most FM stations and sounds really strong so the tuner itself seems to be ok. It just getting the stereo to light up that's the trick.

James
 

jimmyjimmy19702010

Member (SA)
May 5, 2012
3,578
26
38
Sunny Brisbane, Australia
Hi Guys,

Well I've got the old girl working now with FM Stereo!!! ;-)

I double checked that the R22 Semi Adjustable Resistor is the one to adjust and after marking the original position, I turned the resistor to the full left and then the full right position.
(Picture of tuner board: The R22 resistor is the one of the left:)
View attachment 2106

After turning it slightly back to the left, the stereo light turned on. After adjusting it back the full left position, the FM light only turned off at the almost full left position. I then returned the adjuster back to the original, factory position and it works beautifully. Even with the antennas retracted, I get stereo on all stations both near and far!

I would assume a little corrosion, dust etc must have settled inside the adjuster and it just needed a few turns to clean things up!

I wish all repairs were this easy!!

James.... :-)
 
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