[Hallicrafters] BFO on SX-16

[mac]

Mike,

The arm  (center terminal) of the "BFO Injector" pot in the SX-16 is  
bypassed to ground through a .01 mfd capacitor which would appear to  
have failed (shorted) in your radio and must be replaced.  Very good  
idea to replace all other capacitors of this type (and certain others)  
in your radio as mentioned by Carl.  Also likely that you have  
destroyed your replacement pot as well.  As a general rule, if  
something smokes best not to install a replacement until the original  
problem has been identified and corrected.  Recommend you seek some  
hands-on assistance from someone who has experience restoring  old  
radios of this kind.

Good luck.

Dennis D. W7QHO
Glendale, CA



On Nov 1, 2009, at 11:43 AM, Mike & Kathy Ball wrote:

> I just replaced the 'BFO Injector' pot on my SX-16, in hopes of  
> repairing the BFO.  When I turn the BFO switch on and crank up the  
> pot, I do not hear the oscillator, and the pot glows and smokes.  I  
> thought perhaps the pot was bad, so with the help of George Frost  
> (who sent me a replacement), today I installed the replacement.   
> This time, when I carefully turned-on the BFO, and brought up the  
> pot, again-no tone, and in addition, I heard a crackle from the pot  
> at about the 3/4 full position.  I quickly turned the control off,  
> in hopes of not damaging the pot that George sent me.  Would anybody  
> be able to give me a clue where I should look to trace the problem.   
> I did change the BFO tube (6J7), no difference.  Just wondering if  
> anybody else has seen a similar problem and could share the  
> experience with a not-so-experienced SWL'r.
>
> Thank you much, and thank you again George.
> Mike
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