Wireless Set No. 52 Canadian - Project

[David Dunlop]

My initial thought with these four Knobs was to pull them off the Main Set Receiver to restore their luminous paint indicator marks, as per what I had done for the five Knobs, Phenolic, Pointer, but then I realized each of these four Knobs are held in place with two grub screws mounted 90 degrees from each other and that was an awful lot of fiddling with Bristo Wrenches.

Closer inspection further convinced me to leave these four Knobs in place when it became clear the marker spots on the front of each knob were actually drilled into the knob, as per the similar indicator marks on the caste zinc Handles No. 72. With the receiver out of the Carriers No. 4 and on its back on the work desk to remove the two KNOBS, Metal No. C1 for restoration, along with the HANDLES, No. 80, these knobs were in the perfect position to be worked on as well.

Only one of the four Knobs still had luminous paint at the bottom of its hole. The other three held basically just dirt. A 1/16-inch drill bit was the perfect size for cleaning up three of the holes. Twirling it back and forth in the holes with ones fingers worked a treat! The fourth and last hole, not so much. That sized bit was ever so slightly too large.

When I go around to putting a mirror behind the last Knob and comparing it to the other three, I finally noticed some casting marks on it, which were different from the marks on the other three knobs. Probably two different makers involved in production. So out came a large darning needle and with a little careful poking, all the dirt was successfully removed from this knob,

The two attached photos show the holes in the face of two of the knobs prior to any work being done. The second photo is the same two knobs after cleaning up the marker holes and adding in a drop of flat white base paint with a toothpick. As the paint dries this afternoon, it draws down into the hole and by later this evening I can follow up with small drops of the neutral luminous green paint to finish these four Knobs.


David

[David Dunlop]

With the Main Set Receiver now on its back on the work desk again, I was able to remove the Handles No. 80, Flick Lever Control, and the two heavy KNOBS, Metal, No. C1 that are used to pull the receiver out of the Carriers No. 4, and stuff it back in.

The upper KNOBS assembly came out nicely along with its star washer and 10-32 Hex Nut. The lower Knob, under the loud speaker took a little more work than it should have done.

Behind the front panel of the receiver, the lower KNOBS, Metal, No. C1 is used as a ground stud for an electrical circuit. It holds one of those teardrop shaped ring terminals on a wire lead. The type of terminal that serves as a lock washer. The 10-32 Hex Nut and the terminal came off the stud on the base of the Knobs assembly OK, but it took some coaxing to get the Knobs itself free from the panel. I have to take a closer look this evening.

The two Knobs and the Handle have now been cleaned and base coat primers applied to them all. With luck, and no snow tomorrow, they should be able to get their topcoat of Gloss Navy Grey.


David

[David Dunlop]

I was able to apply the final Gloss Navy Grey top coat of paint to the Handle and Knobs of the Main Set Receiver this morning.

They should be cured hard over the weekend and the luminous indicator mark can be reapplied to the Handles No. 80 and all three items reinstalled on the receiver.

David

[David Dunlop]

It certainly pays to review ones notes after a portion of a major project has been side tracked for a while.

I willed myself to do that last evening and it paid off!

The first thing I ran across was the need to get the AE Terminal on the front of the Receiver properly aligned so it points directly to the upper right corner of the FREQ. ADJ. Decal to the left of it. There is not much length in the connector between the Receiver and Sender to play with. I now have the trusty toothpick in place and reference point marked on the upper side of the chassis to adjust this Terminal. All three in the Wireless Set will then be correctly aligned.

The second thing I needed to do was buff down some sections of the two chassis bottom rails on the receiver, where rust had reached the point of small, crusty bubbles, and some corresponding rust bubbles on the floor rails of the receiver compartment in the Carriers No. 4. Things need to be as smooth as possible to slide well on that nasty gloss NATO Green paint that got slathered all over the inside of the Carriers.

There was also a small inward bulge in the upper left side of the Carrier left side panel, near the upper bolthole. It made things potentially snug, so a few gentle taps with a 5 lb. mallet dressed that back nicely as well.

So far so good.

David

[David Dunlop]

The bottom chassis rails on the Receiver are now cleaned of all the lumpy rust and should slide quite nicely now in and out of the Carriers No. 4. Fingers crossed anyway…

Also managed to get the Terminals Aerial No. C1 on the front panel correctly oriented.

David

[David Dunlop]

It appears as though the problem I was having getting the lower Knobs, Metal No. C1 off the front panel of the Receiver was a result of it not being reinstalled correctly the last time it was removed.

The upper Knobs assembly was just fine and it is the one on the receiver that mounts directly to the lower front panel plate by means of an external tooth lock washer and 10-32 hex nut.

The location of the lower Knobs assembly places it where the lower front panel mounts directly over the front portion of the lower chassis box assembly. The row of six toggle and rotary switches running along the lower section of the Receiver are all mounted directly to the front of the lower chassis box. Holes are punched in the lower front panel plate to allow this plate to clear the hex nuts holding all these switches in place.

Because the lower chassis box is directly behind the front panel in this area, the designers at CMC threaded the hole in the lower chassis box so the 10-32 stud on the base of the Knobs, Metal No. C1 can thread directly into the chassis box for maximum strength when pushing and pulling the Receiver in and out of the Carriers No. 4. When this particular Knob assembly was last installed, it was not threaded all the way flush to the front panel by hand. There was a small gap left. When the electrical grounding terminal was attached to the stud of the Knobs behind the chassis and that hex nut run home, it ended up pulling the Knobs down flush with the front panel on the outside, but in the process of doing so, the threads in the metal of the lower chassis box plate were pulled inwards, When I now tried to remove the Knobs, the bent threads were binding on the stud of the Knobs assembly. A quick in and out with a 10-32 Tap and the problem was solved.

With the two Knobs now reinstalled and the Handles No. 80 refurbished, the Receiver finally looks like it belongs with the Sender.

I am going to take advantage of the Receiver being out of the Carriers No. 4 for a while and run some tests on it again with the ZE-11 Remote Supply.

David

[David Dunlop]

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