SS 3900 SSB Carrier Noise Fault

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johnny123
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Re: SS 3900 SSB Carrier Noise Fault

Post by johnny123 »

M1JWR wrote:I hear a roumer he has cracked it, its on soak test, so fingers crossed
So far so good. Seems to be working OK now. Changed the VCO transistors and resoldered a couple of potential dry joints, refitted the SO42 mixer as pin 1 had been folded under the IC when manufactured and done a retune of the off sets. Changed R260 for the carrier balance adjustment to the correct value during trouble shooting. Should be a 270K but made no difference. After the transistor changes put the 10k back in which was fitted during manufacture and re-adjusted VR7 and all was well.

Thanks to all for your feedback.
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cb4ever104
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Re: SS 3900 SSB Carrier Noise Fault

Post by cb4ever104 »

Thanks for letting us know .

Sammy
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Paul aka "Sammy". (108) PY60 Old Paisley DX Group (RIP Rab Markie)
Ex GM0 , now EA5 .
Handle "Fortune Hunter" back in "the day"
Radios ....? Anything that says "TAIWAN R.O.C" on the back.
wizzer2k
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Re: SS 3900 SSB Carrier Noise Fault

Post by wizzer2k »

Sorry to resurrect an old thread but just had a 3900E doing the same thing
PCB screws checked for tightness and all ok
SSB Cartier balance checked and adjust correctly
Driver and Final bias checked as adjusted correctly
Traced this to one of the lugs from the chassis to pcb was not connected it was folded under the board and was hard to notice
This was the one near to the VCO area repositioned and soldered back in place problem solved
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cb4ever104
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Re: SS 3900 SSB Carrier Noise Fault

Post by cb4ever104 »

I had a similar issue with a Dirland 3900 . I had no SSB carrier with the cases on , but carrier with them on . Nick gave me some advice(below) , which cured the problem on mine .
Black Spirit wrote:07 Jun 2015, 18:29 I just happen to notice that radios with say the 2312 final and 1969 final had slightly different value caps, A 148 PB010 for eg has a 271pf whereas the 3900 has various from 271 to 331 so on a 148 PB010 that had a 1969 instead of a 2312 and was warbling on SSB with top lid on i replaced the cap and warbling stopped, So when i had a 3900 with the SSB carrier issue i tried it and that also worked but i had to lower the value alot more than usual and output dropped a bit too so by adding the 47p across it on solder side upped the output back and carrier still remained at zero.
Sammy
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Paul aka "Sammy". (108) PY60 Old Paisley DX Group (RIP Rab Markie)
Ex GM0 , now EA5 .
Handle "Fortune Hunter" back in "the day"
Radios ....? Anything that says "TAIWAN R.O.C" on the back.
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14CS06
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Re: SS 3900 SSB Carrier Noise Fault

Post by 14CS06 »

Hello Paul

Same problème on my SS 3900 BLACK

the lugs from the chassis to pcb was not connected

Image

@+
Claude
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