Wireless Set No. 52 Canadian - Project

[David Dunlop]

Things took an interesting positive turn while working on the Negative Connectors Cable this last week.

I started with the usual cleaning to remove the years of waxy dirt accumulation, which resulted in pretty much the same amount of filth on my cleaning cloth as I obtained when cleaning the Positive Cable earlier. The surprise was in just how good a condition the original black coloured cotton loom was under all the dirt. So nice was it, I decided against applying any of the black shoe cream to it. Just a light rub of the Kiwi Neutral Shoe Polish and I was happy with the result.

Another find, or discovery, with the Negative Cable I had completely missed since obtaining the CONNECTORS, Twin, No. 17, was two little electrical tape patches on it. I have seen so many tape patches on electrical cables over the years, I rarely ever give them a second thought. They are always the same. A circular wrap of any number of layers of tape carefully wound over the damaged cable. These two were brand new to me, however. See the attached pictures.

When I first noticed them, I was looking at the full tape side and what struck me was that a rather wide roll of tape had been used to wrap the cable. Then, when I rolled to cable over to check for any possible loose end to the tape, I discovered these two repairs were not the usual circular warp of tape, but a careful build-up of several layers of rectangular cut patches of electrical tape. This was a first for me seeing this kind of repair. At first I thought the patches had shrunk and split but a careful look at the two opposite edges on both patches showed they were not the same lengths, even down through the layers.

I have no idea when these repairs were done, either in Military Service or in civilian life, but they are unusual enough to me to warrant they be preserved as is on the cable.


David

[David Dunlop]

It was very helpful that I switched over to work on the Negative Connectors Cable while waiting for the first coat of red shoe cream to set up on the positive cable. With the negative cable all cleaned up, I now had a reference point to match to regarding the overall look of both cables. I had not thought of it earlier, but there was a likely chance I could have over restored the look of the positive cable and had to try and redo it.

As it was, with the negative cable looking the way I wanted it, I rubbed back the excess polish on the positive cable and then applied a lighter second coat where needed of the red shoe cream and let it set up before a careful buffing.

Then came an application of the Neutral Boot Polish to cut the potpourri scent and help hold the arrived at red colour I wanted in the cotton loom, Yesterday, when I was giving the positive cable another buffing, it was still shedding far more colour than I liked, or expected. After thinking about it for a bit, I realized that with the wax base of the polishes in the cotton now, the only thing that could bind the colour to the cotton was a lacquer. Anything water based was not going to work at all. As it turned out, I had a can of Rust-oleum Painters Touch Flat Matte Clear Lacquer (#268390) on the shelf, so the positive cable got a light coat of that yesterday afternoon.

Checking the cable with a white cloth this morning showed the colour transfer is all but non-existent now and the outer surface of the cotton loom still looks and feels like cotton.

Next step will be to redo the cotton cording on the battery terminal ends of both cables.


David

[David Dunlop]

Today’s little adventure was to redo the cotton cording on the battery terminal ends of both Connectors Cables. I started with the negative cable as that cording had already started to unravel.

The first step was to determine the original length of the cording. This worked out well as a good shadow line had survived on both copper terminals. The length was found to be one inch. I then marked the start point for the cording on the cotton loom with a wrap of masking tape.

I did not realize the significance of the observation when I redid the negative cable cording, but a noticeable portion of the factory cotton twine appeared stuffed into the gap between the end of the cable covering and the end of the copper terminal fitting. I just assumed that had been a simple place to put the unravelling twine to keep it out of the way.

As I unwound the original twine, I came across a knot and then worked my way back down the loom to the tape. It was interesting to see how the cotton cording twine had cut into the cotton loom on the cable over time, and also how nicely the new cotton twine fit right into those grooves as I redid the cording. I did wonder, however, how I was going to deal with the gap between the covering and the terminal fitting. One often finds a wrap of the old cloth electrical tape covering such gaps but no sign of any at all in this application. So I went with what I had on hand and cut a length of twine, which I wound tightly into the gap to fill it in level as best I could, tied it off and trimmed it. I then proceeded to do the cording. The last time I had done this I was annoyed by the large spool of twine bouncing around the work desk while using it, so this time I rigged a temporary spool holder off to the side, which worked a treat! The final transition from cable to fitting was not as smooth as I had hoped but liveable. The big problem to me was the cotton twine was far too white.

Since the twine was going to get an acrylic top coat when finished, I thought I would use a bit of stale tea and brush it on to the twine to colour it up a bit. Two light coats gave it a nice light beige colour I was happy with and also helped tighten up the twine a bit as it dried. It then got a good top coat of satin Urethane finish to seal it in place.

Things got interesting when I started working on the positive cable. I found the end of the twine tucked under the battery terminal end of the twine, freed it up and started unwinding it. It unwound right passed the gap and continued on towards the marker masking tape I had placed at the starting point for this cording. When I got to the tape, at the last band of twine, it jumped back to the gap again and stopped at a knot. I was able to lift the knot just enough to cut the twine behind it and unravel the section that had been wrapped into the gap. In the second photo you can see the two pieces of original twine. The negative piece is on top and the positive one below it.

So now I realize how they dealt with the cable gap when cording these cables. They started by carefully infilling the gap tightly with twine. When they got to the top, they tied the infill off and then brought the twine down the loom to the required start point for the cording and started the wrapping process back down the cable to the battery fitting. In the process, all the twine leading to the gap, and in the gap, disappears. Armed with that newfound knowledge, I carefully duplicated the process when cording the positive cable and was quite pleased with the transition point and final look. That cording also got the tea stain treatment (coffee would probably work just as well) and the top coast of satin acrylic.

Both cables should be fully cured by tomorrow so I can reassemble the CONNECTORS, Twin, No. 17 and plug the Main 52-Set back in. I have actually missed listening to it over the last week or so.

By the way, in the last photo, no matter how I tried, the camera wanted to make the new cording look ‘camera white’. In real life, it is very much a nice cream colour.


David

[David Dunlop]

One small detail I decided to add to the Connectors Cable Assembly was a replica C-Broad Arrow Stamp to the cording at the battery terminal end of the negative cable. These markings have been on my mind for a number of years as legitimate, historical marking for Canadian Military equipment, but it has only been in the last year, or so, that I have been able to satisfy myself the markings are truly defunct and no longer in use with modern equipment. It also did not hurt to get a positive boost into working with these markings after seeing the great job Jordan Baker did with replicating the canvas cover for his FFW 15-cwt.

I have several other battery cables made by Canadian Marconi Company for use with the 52-Set, these being the short interconnection cables between the sets of two 6-Volt Wireless Batteries. They had the luxury of a rubber stamp for their work, but the ribbed surface of the cording means the stamp only reaches the outer edges of the ribs and the C-Broad Arrow is not as well defined as it would be on a flat surface. The cables I have were marked in blue ink.

Without a stamp, I had to improvise and what I discovered was Carters still makes black carbon paper for old fashioned typing copies and Staples sold packets of 12 sheets for $4.00 Cdn. So I bought a packet. I then photographed a C-Broad Arrow stamp on a piece of equipment and sized it to just over 3/8-inch diameter and printed out a copy. Taping down the negative Connectors Cable to keep it stable, I did a simple rubbing transfer to copy the mark over to the new cording on the battery terminal end of the negative cable and it turned out not too badly. A thin wipe of satin Urethane over top and it was done.

When reassembling the two cables into the Bakelite Connectors assembly it was really nice to see how easily they now slipped into place having been cleaned. The last two pictures show the restored Connectors, Twin, No. 17 reconnected to the Supply Unit and the 12 Volt DC Power Feed System.


David

[David Dunlop]

Sometimes I forget what I started out with.

I dug these two photos up of this Connectors assembly when it first arrived back in May, 2019.


David

[Harry Moon]

While I'm relatively new to radios and related equipment and probably will never make the commitment as you have I do want to pass on how impressed I am every time I check in on this thread. Inspirational.

[David Dunlop]

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