[Hallicrafters] SX-101A Converter Subchassis

[Harry Vaught, KT4AE]

Over the years, sometimes when the 12BY7A oscillator tube in my SX-101A 
was going bad, the receiver would start jumping in frequency.  I also 
had a lot of trouble with it drifting and jumping until I happened to 
install the 12BY7A it had been waiting on.  I've read of others swapping 
the 12BY7A until they get the right one.

I don't recall the mode switch on mine affecting the frequency, but 
wiggling the bandswitch does.  Cleaning helps, but I suspect that 
running the switch back and forth every day would help more. 
Unfortunately, the receiver can go a while without being used.

Harry, KT4AE
Maryville, Tennessee

Mark K3MSB wrote:
>
> 
> The radio decides to change frequency every now and then, and I can
> typically "make it better" by changing the mode switch back and forth
> a few times.
>