Wireless Set No. 52 Canadian - Project

[Harry Moon]

at some point I do want to get the 19 set up and running, Bruce McMillan moved away from being local to somewhere in Kent England. If anybody knows of a knowledgable person near my home in Burnaby BC that would be great to know. Close to my house is relative, I think we will be able to get out on the highways once they are all rebuilt.

[David Dunlop]

I hope things get back to normal quickly for you, Harry.

Having thought about it for the last day or so, I have decided to tackle the internal issues with the Supply Unit next. I think it makes the most sense to the overall progress of the project. The outside may look scruffy for a bit longer than I would like, but the performance of the set as a whole will take a quantum leap forward.

David

[David Dunlop]

And off we go, into the unknown yet again!

I have now pulled the Supply Unit from the Carriers No. 4 and it is sitting on the bench ready for a close inspection. This Supply Unit is getting interesting already.

Overall, the interior chassis assembly is remarkably pristine. Only the top surface has accumulated any significant dirt and/or surface rust and that should all clean up fairly easily. This condition looked odd, in light of the fact the Serial Number for this Supply Unit is 5792. That is early production. The other interesting bit is the Blower Cover and Receiver Vibrator Supply Cover on the front still clearly show the factory original Gloss Navy Grey paint, The discoloured varnish top coat is only on the main Supply Unit Panel that had new decals applied during the 1966 Workshop overhaul. The only reason I can think of for the replacement of the decals is that somebody assumed they were radioactive paint. That would fit nicely with the fact the Sender panel had two decals added to it stating the paint WAS radioactive. It is not. All the more reason to be happy the decals will eventually be replaced with ones patterned after the originals down the road.


The Modification Card, still in place in its holder, has proved a gold mine of useful information, which may explain a lot of the history of this, 52-Set. Modifications 1, 2 and 4 were all performed on this Supply Unit 12 June 1966, which is consistent with the 1966 Workshop Decals added to the upper left corner of the front panel. Modifications 1 and 4 are the interesting ones.

Modification 1 was for the installation of the Modification Card Holder. This Instruction was first issued 23 May 1947, when these Card Holders were first introduced and to be applied to all active wireless equipment assemblies. That strongly suggests this Supply was sitting in original packaging from whatever build date it had until it arrived at 202 Workshop, possibly as a replacement unit for the one originally in this particular 52-Set. At 202 Workshop it was unpacked for the very first time, the two Dynamotors upgraded to the improved 1945 versions, the ‘bad decals’ replaced on the front panel and the Modification Card Holder added on the top of the chassis.

Modification 2 was a simple addition of electrical tape around the right hand terminal of resister R38A at the back of the supply to prevent possible contact with the Vibrator Supply Case when it was slid into the Supply Unit Chassis.

Modification 4 gets really interesting again. This was an extensive set of modifications required to prepare the Supply Unit for operation in conditions in the high arctic. Mostly upgrades to grease and other lubricants, but a couple of valves were also swapped out for more cold tolerant ones.

So where did this 52-Set originally come from for servicing at 202 Workshop, or, where was it going to go after completion of the overhaul work, which would have been leading towards the winter of 1966-1967?


David

[Bruce MacMillan]

Harry, check out the Burnaby Amateur Radio Club. There are a few members there that also belong to the SPARC radio museum so they speak tube language. They may be able to point you in the right direction. Sadly the three people at SPARC that worked on military sets (me included) have moved away.

[Harry Moon]

Originally Posted by Bruce MacMillan

Harry, check out the Burnaby Amateur Radio Club. There are a few members there that also belong to the SPARC radio museum so they speak tube language. They may be able to point you in the right direction. Sadly the three people at SPARC that worked on military sets (me included) have moved away.

thanks Bruce

[David Dunlop]

First off, I am stunned at how pristine the interior chassis of this Supply Unit is to look at. Photos will eventually follow.

I took some time to explore the disappearing 2.0 Volts DC from the Low Tension side and discovered absolutely nothing is wrong with this part of the Supply. Whatever I feed into it, shows up perfectly on the +12 Volt Receiver Pin on the rear Connector of the Supply. So!

I have a Main Set Receiver that reports spot on accurate voltages on its meter when fed by the Remote Receiver Supply. When in the Carriers No. 4 and fed with the Supply Unit, the 2 Volts disappears. When the Supply Unit is out of the Carriers No. 4 is shows perfect LT operation. In the Carriers No. 4, 2 Volts disappears. That points to a fault, probably a poor solder joint, in the PLUG ASSEMBLIES, Multi running along the back of the Carriers No. 4. Not exactly the nicest part to have to work on, but at least I know the Supply Unit is looking really good in that circuit.

David

[David Dunlop]

In this post, I want to simply highlight the physical damage this Supply Unit has received. None of it looks even remotely Military Service related and I suspect at least three quarters of it all took place at the same time.

The three common bits of damage are in the first three photos.

Photo 1 is a view of the top edge of the front main panel where somebody took a hammer to it, or a piece of round bar. At first glance, it looked like the work of a small diameter grinding tool, but when you look closer, you can see the effects of an impact force coming downwards and towards the front of the panel. The paint has chipped away from the front face and this impact edge is smooth. The inside edge of the panel, on the other hand has mushroomed in towards the chassis frame. Also, the force of the impact on the left most dent caught the eye screw and crimped it enough the aerial connector cable between the Receiver and Sender can no longer fir through it. Easy enough to restore the eye screw and I think it may be possible to run a simple weld bead along the edge of the panel metal at each dent and dress them down to remove any sign of the dents before I get around to refinishing the front panel. It is interesting to note just how clean the Blower Motor assembly and its related capacitor are compared to the one in the Sender last year. Even better, the dirt on this blower wipes away with a finger.

Photo 2 is the Modification Card Holder mounted to the upper chassis support plate. Note the two dents in it roughly at the midline. They look like the ball end of a hammer was active here. This holder can be removed, straightened and cleaned easily enough, and if needs be a quick zinc plating will restore if nicely.

Photo 3 is the ball end of the hammer at work on the right end of the upper rear chassis frame. Not much I can do about this damage. Most if it is right on the angle edge of the frame piece and pretty much impossible to get at. But the dirt should clean up from around it OK.

It is these three bits of damage I suspect all took place around the same time when this Supply Unit had been pulled out of the Carriers No. 4 for some reason.

Photo 4 is the last bit of physical damage that I have found that makes no sense to have happened in Military Service. It looks very much like somebody wanted to have a look inside this 5-Pin Connector. The body of the connector shows signs of being held in either a vise, or vise grips, while another set of pliers went to work attempting to pull the central core out of the connector. Clearly they did not succeed, but the connector is distorted beyond use now. Fortunately I have an NOS spare on hand I can swap out once the front panel comes off for restoration.

There are a few other physical oddities that have shown up, but I am pretty certain they are part of the Military Service History of this Supply Unit and I will cover them later.

David

[David Dunlop]

A bit of an ‘Errands Day’ today, but I have managed to remove the Vibrator Supply from the Supply Unit. A simple enough task as one just removes the two drop leads from the front clips, unlocks the two Cowl Fasteners and pulls on the handle.

In Photo 1, you can see the two side flanges of the inner sheet metal case for the chassis of the Vibrator Supply and at the back bottom, the small square cut-out in the case that allows the three banana plugs to connect with their sockets. These are the +12 Volt and Ground Input Feeds and the +150 Volts and Common Ground outputs.

In Photo 2 you have a side view of the Vibrator Supply Cover stuck in position where it blocks access to the right side upper and lower Rotary Transformer Mounting Hardware quite effectively. Note, however, the delightfully clean look of the chassis. Apart from the heavier staining/dirt at the very front and top surface of the chassis , the rest is just upper surface dust. I am being spoiled!


David

[David Dunlop]

Not actually knowing what the problem was, I probably erred excessively on the side of caution when it came to attempting to remove the Cases, Metal C1 from its tray in the Supply Unit. After carefully looking in all the usual places for signs of rust, varnish, or even soldering/welding, and finding none, I decided the best approach was to use a small block of wood against the central outer edges of the case at the exposed back of it, and start tapping with a rubber mallet.

The fist couple of taps got the Case to back out about an eighth of an inch, which was a very good sign. About 5 minutes of alternated taps from side to side eventually got the Case out until just over an inch was still in the Supply Unit. At that point, a quick, straight out tug, with hands on each side of the Case, brought it out, for what I now realize, was the first time since June 1966.

In the first photo it is now sitting free beside the Supply Unit.

The second photo shows the Case sitting on its right side with the front facing to the right of the image. You can see the slight oxidation along the lower edge of the side where it sat in its tray. Note the interesting patch mark in the upper left rear corner of the side. I did not realize the significance of this right away.

The last photo is the top of the Case, again with the front facing to the right of the image. At the back of the case, about an inch or so in, you can just see traces of a line running perpendicular to the longitudinal axis of the Case. This is a good thing. The long line running the length of the Case, and the other shorter ones, are not.

The Canadian Marconi Part Number stamped onto the top of the Case was also a surprise. This is the first time I have ever seen a CMC Part Number using a ‘Forward Slash’ between the two parts of the number. Every other CMC Part Number I have seen to date has used a ‘Dash’.


David