[ARC5] OT: Hally Instability

[David Stinson]

Lots of folks are addressing thermal drift, but IMHO
that's not the big issue with Hally instability.
The big issue is mechanical- the "wibble wobbles" 
above 10 or 12 MC when you just tap the table.   
With the last SX-101 I had, a window air conditioner
across the room coming on would FM the 
LO in the receiver.  

Has anyone ever tried to determine the source
of this mechanical instability?  Cheap tuning cap?
LO coils mounted by their wires on the band switch?
Anyone tried to find out?

73 Dave S.