| Author |
Message |
    
Hotrod
| | Posted on Saturday, August 31, 2002 - 12:56 pm: | 
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I HAVE A BUDDY OF MINE THAT HAS A GALAXY 33 AND WHEN HE TALKS TO ME IT SOUNDS GREAT AND THEN HIS VOICE WILL GET LOWER AND LOWER UNTIL I CAN'T HEAR HIM NO MORE.IT WILL KEY UP LIKE HE'S TALKING TO ME BUT NOTHING.HE CAN TURN IT OFF FOR A MINUTE AND TURN IT BACK ON AND IT WILL WORK FOR A FEW MORE MINUTES AND DO THE SAME THING AGAIN.WE SWITCHED A COUPLE DIFFERENT MICS.AND STILL THE SAME THING.ANY SUGGESTIONS ON WHAT COULD BE WRONG AND WHAT TO CHECK?? THANKS,HOTROD. |
Taz
| | Posted on Saturday, August 31, 2002 - 1:24 pm: |
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batteries batteries batteries
hahaahhaha
No, hmmmmmm I have no idea. |
2600
| | Posted on Monday, September 02, 2002 - 2:54 am: |
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You didn't say if a wattmeter in line with it drops off as you hear it fading away. If it DOES, my prediction is that the modulator transistor is the smaller one, same physical size as the driver/final transistors. The 'skinny' modulator transistor just doesn' hold up. The best way to tell is to measure the modulated juice that comes out of the center lead of the transistor bolted to the side of the chassis just to the front of the power socket. If this reading drops out in step with the wattmeter and audio as they drop off, replacing the skinny one with a 2SB754, like the larger models use is the routine fix. You'll also need a larger mica insulating washer, longer mount screw, and heat sink compound to install the larger part. Sounds like a job for somebody with a 'scope. If it already has the 'fat' 2SB754, then you REALLY need somebody with a 'scope to track this one down.
One simpler possibility, make sure the mount screws on the driver, final and modulator transistors are tight. If they come loose, the transistors pull away from the aluminum panel. This is a guaranteed way to overheat any of those three parts. If one of them was replaced, and they skipped the white heat sink compound, they can overheat even if the mount screw is tight.
73 |
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