[Elecraft] K1 VFO freq jump, 100 kHz

[Wallace, Andy]

I am trying to repair my dad's recently built K1-2,
which is ser 12xx and has the latest rev. RF board.

It was working okay and then all of a sudden he
was 100 kHz too high -- 7.100 and 14.100 MHz 
for example. 

The VFO output is 100 kHz too low. Instead of
being approximately 3.1 to 3.0 MHz, it is
3.0 to 2.9 MHz!

I rewound the VFO coil, and checked the VFO section of the
schematic. Components were correct  -- up to U7,
the premixer -- but I saw that
two of the polystyrene caps had blobs of solder on them.
I was afraid the solder had shorted out some of the foil and
raised the capacitance, so I replaced them with a couple of
SMT versions I had on hand. 

That didn't help. But at some point, perhaps when I went to
fasten down the VFO coil again, the range was correct!
So it is intermittent. It's not the coil wire itself as
I replaced it. Doubt the core was cracked....

Snapped back to being off freq again...

In looking with a scope, the high side of the VFO coil,
L1, shows the same frequency as displayed on the CAL-OSC
menu setting...100 kHz wrong...

The 6V regulator is dead on.

The VFO pot adjusts from 6V CCW to 0V CW. 

I've tapped components and resoldered connections. I can't seem
to make it jump frequency mechanically. 

Ideas?

-Andy