It pays to keep detailed notes during a restoration project. It pays dividends to actually review them!
I have been trying to wrap my head around the reason why the Supply Unit would have such a significant voltage drop feeding the Main Set Receiver, assuming that simply because the Supply Unit is the new kid on the block, the problem must reside with it. I decided over the weekend to confirm that theory by pulling the Main Set Receiver from the Carriers No. 4 and firing it up with the ZE-11 Remote Supply Unit.
Surprise! Surprise! Same poor readings with the ZE-11 running the show. So out came the Remote Receiver and I hooked it up to the ZE-11. Perfect Meter Readings on the Remote Receiver and the signals came booming in over my 134-foot dipole. I had both the RF and AF controls at maximum and had to quickly dial the AF back about half way to get a nice listening level. Even the built in Crystal Calibrator signals were easily heard. No signals of any kind to be heard on the Main Set Receiver. Then the cobwebs slowly began to fall away and I remembered my notes.
I started working full time restoring both receivers exactly two years ago today and was working on them regularly up until near the end of July, early August 2019 when word of a possible complete 52-Set surfaced somewhere in Montreal, and the rest was history.
Digging a little more deeply into my notes I remembered I had finally got the Remote Receiver up and running very nicely, and the next step for it was going to be an actual alignment and calibration. The Main Set Receiver, on the other hand, had only reached to point of taking electrons through it completely, but not very well. The biggest issue with it was poor HT and LT voltage readings in it. My plan at that time was to start a detailed trace of the circuits starting at the incoming 8-Pin Connector and tracing what went on, using the Remote Receiver as the ‘Benchmark’.
So the odds are now saying the Supply Unit in the carriers No. 4 is probably in good working order, but needing a good cleaning up. A quick check of the +12 and +150 voltages at the Receiver Connector in back of the Carriers No. 4 next time I pull the Receiver, should confirm that point. My thought is the Main Set Receiver now needs to be brought back to good working order. Once it is able to pull in good clear signals, especially its own Crystal Calibrator, I can eventually use it with confidence when time comes to try tuning the Sender to it.
David
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