bpnjensen wrote:

I don't see anything right off hand about a HQ-100X but there was a HQ-120X and that
denoted a crystal filter.

dxAce
Michigan
USA

Thinking back, that calibrator might have been an installation by
another owner. In any case, it worked darn well and helped alot,
especially before full warm-up.

The '100 I had also had an add-on calibrator.

dxAce
Michigan
USA