[QCWA] Collins 51J-3

[Jeffrey D Angus]

A few years ago, I acquired a Collins 51J-3 receiver.
What a sweet part of electrical and mechanical engineering.

Over this past week, I removed the 60+ year old PTO and
re-calibrated it for the correct amount of tuning range.

1. make special tool for the adjustment slug.
2. trim the series padding inductor
3. adjust for 10 turns = 1.000 MHz +/- < 100 Hz
4. oven bake with the cover off at 230F to turn the desiccant blue again
5. reassemble while hot, per factory procedure.
6. reinstall in 51J-3
7. final test
8. stick calibration label on bottom of PTO.

Yuppers, that was a lot of fun.

Jeff-1.0
wa6fwi