Another RCA CT-100 discovery B8001599

[dtvmcdonald]

I did a full adjustment of my CT-100. This includes what I seem to remember
as being 88 adjustments, including only one tuner position. Yes, I turned
every knob or pot or coil.

The IF alignment was quite straightforward. I didn't at the time have an accurate marker generator so I tried two methods: zero beating with the
second harmonic of my frequency synthesizer, which only goes to 40 MHz,
or simply picking up stray signal on my AirSpy SDR and setting at the
correct place. The final result matched the spec perfectly. I did not use the Fig. 22 (RCA manual) test head (just coax with hard wired parts with short leads) nor
the Fig 23 IF test block, rather just a 100 mHz scope with 1 megohm input connected by clipping a tiny alligator clip at the end of 4 feet of RG58 to an insulated wire (tack soldered on if necessary) at the appropriate point.

For the RF, I set the oscillator with the Airspy and just tweeked the response
per spec. For my Ch. 39 UHF strip I kludged it using the Airspy and
the harmonic of my sweep generator.

Its all just a lot of adjustments. I still don't quite understand Zenith's snarky
remark "50 adjustments and they all make it worse" as a complement (i.e. it was done right!) or simply saying that too many.