[R-390] Crystal resurrection

[Roger Ruszkowski]

Mark,

As long as the little variable caps give you two peaks as you dial them around
a full turn or so, they have enough range to properly adjust the circuit.
There is no need to dive into more effort on them.
The peaks may not be the same level do to other distributed capacitance and or
crud in the near field so pick better one of the two if they are not equal.

Roger AI4NI