IF Theory

The question has been put "Do you align the IF chain to the specified 455 KHz frequency or to the crystal resonant frequency, whatever that is?"

It's become obvious that if you want the Sharp Xtal, etc settings to work, the answer is use the crystal frequency.

All this assumes that the crystal resonant frequency is in spec.

The process used here is measure the crystal, adjust the local oscillator accordingly and alighn the IF chain to whatever that produces.
The procedures so far encountered in Hallicrafters documentation and online notes don't take this approach.

The following is from a manual for the National NC-100.

Preliminary Adjustments

From the above explanation, the reader will see that it is absolutely essential that the IF transformers be aligned to the crystal, since the two must work together¹. This alignment may be accomplished in a number of ways...

Footnotes:

1. I tried to use OCR to extract the entire IF text from a NC-100 pdf document but it was so poorly done, it was unreadable. I just used this text. It is the key statement anyway.

Page: /Alignment/IF/Theory/Align_early_if_theory.shtml

Last modified: Tuesday, 14 Jul 2026