[Hallicrafters] SX-16 partially died on me...

[Richard Knoppow]

----- Original Message ----- 
From: "DJ" <fourzulufive at yahoo.com>
To: <hallicrafters at mailman.qth.net>
Sent: Sunday, December 02, 2012 11:49 AM
Subject: [Hallicrafters] SX-16 partially died on me...


> Hi,
>
>
> I have an SX-16 (first generation). I recapped it about 8 
> years ago and re-aligned it, pretty much did the full 
> service on it - even put in tubes that all tested very 
> good. It was quite a hot little performer when I got done.
>
> Now I went to turn it on after about a 3 year hiatus, and 
> bands 1,2 & 3 are deaf and 4 has a little reception on it. 
> Bands 5 & 6 are coming in great, but they might be 
> slightly desensitised too, but I can't tell now.
>
> I went through and gave everything a "good" cleaning just 
> to make sure. Didn't "see" anything out of the ordinary.
>
> What should I look for or maybe where should I start. I'm 
> at a loss.
>
> Best Regards,
> Douglas
>

   Its certainly a bit of a puzzle.  This is a fairly simple 
receiver and nearly everything is common to all the bands. 
One thing I would suggest is, if possible, listen to the 
local oscillator on another receiver.  Its possible its not 
oscillating on some of the bands or is oscillating weakly. 
Possible causes are a failure of C-21 or C-22, the two 
coupling caps for the LO. Also check R-7.  It may be useful 
to check the socket voltages of the LO, mixer, and RF stages 
to see what is changing there. I think its still possible 
something has happened to the band switch, worth at least a 
very close inspection.


--
Richard Knoppow
Los Angeles
WB6KBL
dickburk at ix.netcom.com