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Old 04-12-21, 18:02
David Dunlop David Dunlop is offline
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Join Date: Feb 2006
Location: Winnipeg, MB
Posts: 3,384
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Thank you for the encouraging words, Harry. They are very much appreciated.

I find I am at a bit of a cross roads with the Project once again, in so far as what direction to take next. I am rapidly running out of things I can do to completion, and I hate partially starting something and then having to set it aside, particularly if it is in a state of disassembly.

When I look at the Main Set Assembly now, I know the Receiver is working, as it should. All of the problems I was aware of in the Sender have been fixed, the Heater circuit functions correctly, the Blower works and all the tuning circuits work, in that the Receiver responds as it should to any tuning adjustments made on the Sender. This latter point also transfers nicely over to the Coils, Aerial Tuning Unit. The Receiver now also responds correctly to any tuning adjustments made to the Coils Assembly.

Further work on the Coils is purely cosmetic now. It needs to be fully disassembled in order to get rid of the nasty NATO paint job it received, unfortunately inside and out, and restore the wood to the original Flat Olive Green Canadian Marconi had applied to all the wooden items they built for the 52-Set. While the guts of the Coils are out of the box, the two decals on the front panel need to be returned to originals. They are currently the late post-war stick on style with white painted printing and a white border around the perimeter. The originals were the same water slide transfer decals the rest of the set had – plain black with green phosphor luminous lettering. The paint on the Coils front panel is not original, but a close match and I would like to keep it. That will depend on how successful I end up being in removing the two current decals. The big catch here is I do not have a new enough computer to be able to create the necessary artwork for the water slide decals I need to make. So finishing the restoration of the Coils can logically be put on hold for the time being. Other than the wrong ‘look’ to it, it is in excellent shape and working exactly as it should.

That brings me to the Main Set Supply Unit. The front panels absolutely need a full restoration as a result of damage, sloppy work and incorrect decals. Once again the same decal issue, so that exterior work has to wait.

On the inside, there is lots to do and some strong logical reasons for getting it all done.

The Receiver Vibrator Supply section is working almost correctly. The mystery here is the disappearance of 2.0 Volts DC from the Low Tension circuits. I have 12.73 Volts arriving into the Supply Unit but only 10.75 shows up on the meter. Correspondingly, I should be getting +150 Volts DC High Tension out of the Vibrator Supply section for the Receiver and I am only getting between +130 and +135 Volts DC. Most, or that entire drop, is likely related to the lower than normal Low Tension feed getting to the Vibrator Supply. My current thought is there are one or more bad soldering joints along the Low Tension path that are pulling the voltage down. So I need to find and fix that problem.

Second problem I am aware of with the Supply Unit also relates to the Receiver Vibrator Supply Section.

When I undo the two Cowl Fasteners and pull the Vibrator Supply out, all that comes out is the chassis. There is a sheet metal case that fits over the entire chassis that is supposed to be removable, but it stays firmly stuck inside the Supply Unit. Not good because it needs to be out of the way to access the mounting hardware for the two Dynamotors. The two Dynamotors are my biggest concern with the entire 52-Set.

I am fortunate the two in this Supply Unit are the upgraded 1945 issue ones that solved the overheating problems of the originals. From the outside they look to be in good shape, but it is the innards that are going to need some TLC before I can even consider firing them back up. The end bearings on both need to be cleaned of 1966 grease and repacked. This is the type of grease that looks like golden honey when you scoop chunks of it out of a can fresh new, so I can only imagine what it has turned into now. Adding to the fun, the original grease is no longer made so I need to find a modern equivalent.

All the brushes on both Dynamotors also need to be carefully removed, inspected and cleaned and put back in exactly the same position as they came out. And while out, the armatures of the dynamotors need to be turned by hand and carefully cleaned. If that work is not exciting enough, I have to be able to do it knowing there are no known replacement parts for any of this stuff, should anything end up needing to be replaced. Hence my reservations at the moment about diving into the guts of the Supply Unit.

Countering all that, the ‘Plus Side’ of getting the internal work on the Supply Unit completed, will allow me to finally test the actual transmitting circuits in the Sender. I can check the individual components for effectiveness until the cows come home, but still at some point have to hit them all with high voltages and see what happens.

I will keep you all posted.


David
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