Wireless Set No. 52 Canadian - Project

[David Dunlop]

I have had a chance to compare this Aerial Base C2 to the diagrams of it in the 52-Set Instruction Manual. It looks like only two pieces are missing: a small wire D-ring at the very bottom of the assembly, used to retain the wing nut, and, the large 9-inch square, 1/4-inch thick, brown, phenolic plate which fits between the two ceramic insulators.

Drawings of the plate with specifications are provided in the Instruction Manual for everything except the central hole in the plate.

In order to provide effective RF Insulation in transmit mode, this central hole at the very least has to be large enough to safely clear the central conducting core of the aerial base. At its largest, it might be sized to allow the large collars of the two ceramic insulators to lock into the plate on either side to hold the aerial base in position.

Is there a surviving phenolic plate assembly out there somebody can reference the central hole size from, for me?

David

[Chris Suslowicz]

Hi David,

Assuming the upper and lower ceramic insulators are 'stepped', then the hole in the mounting plate should match the smaller diameter of the insulator, and there will be a rubber or leather washer under the upper insulator to keep rain out of the vehicle. (There will also be a square gasket that goes under the mounting plate for the same reason - I'm not sure what (if anything) they did to seal the mounting bolt holes, unless the square gasket also did that.)

I've got the British equivalent of the roof insulator, which is a ceramic mushroom of considerable size and weight supporting Aerial Base No.3 to provide flexibility for use on the move. Because Base No.3 was never intended to be fed from underneath (and was probably not up to the task for WS53 or ET4336) it's bypassed electrically by four braid straps and the mushroom does the insulating job. That lot mounts via a Tufnol plate (or to a steel bracket behind the cab on the "wireless light" vehicles) and I suspect the plates and gaskets are similar in external dimensions.

Chris.
(Not going anywhere (except possibly back to bed) at the moment, I have a foul cold.)

[David Dunlop]

Thanks for your feedback, Chris, and for reminding me to get my Flu Shot soon. Hope you are feeling better in time for work next week.

There is, indeed, a noticeable step at the wide ends of the upper and lower porcelain insulators. Both also have what I thought were thin, hard fibre washers around the steps. A closer look after reading your post and I realized they are dried out leather. Several other fittings along the aerial base also have these gaskets and I think if I can track down a bottle of Neatsfoot Oil locally, they should all revive nicely. So I shall size the centre hole on the phenolic plate to fit the insulators.

As for the lower side of the plate, Chris, the edge is lined with a thin gasket that does cover the 8 mounting bolt holes. It looks to be about 1 inch wide and looks like it could either be cork, or a material I cannot think of the name of at the moment. Kind of a synthetic cork, made of little black, grey and brown speckles, all fused together.

David

[David Dunlop]

This arrived at the local Post Office yesterday, from a good friend, and I picked it up on the way home from work today. With its arrival, I now have the complete set of three wooden parts and equipment cases issued with the Wireless Set No. 52 Canadian.

It is in very fine condition, the interior being basically new, finished in flat Olive Green. The exterior was stripped of original paint and a coat of NATO Green applied, late in its Military Career and then a second overcoat of thick tan paint was applied to the front portion of the case and another set of NATO markings applied.

Interestingly, the original wartime Parts List for the case is still glued in place on the inside of the lid and a two page listing of the same parts was also still inside the bottom of the case. This second list references the parts by the newer NATO Parts Numbering System.

The ZE-12 Remote Supply is stored in the central compartment and can actually be operated from inside this case in situations where there is a lack of space available where the 52-Set is operating.

The small right side compartment is lined with Kimpak and is where the spare valves, fuses and light bulbs were stored.

The left side compartment held the cables, horizontal aerial, aerial insulators power cables and headsets for the Remote Receiver.


David

[David Dunlop]

This little (though remarkably heavy) gem arrived in this morning’s Mail, the beginning of the end of a process that started several weeks ago.

The Serial Number is 5792 and the interior chassis area, apart from a little dust, is almost factory new. The front panel, tells a somewhat different story. This set was sitting quietly in a work shop down East for several decades. Said shop appears to have been heated by means of either a wood stove or oil stove, which threw a lot of smoke. The photo of the front panel does not do the amount of crud accumulated on the panel justice at all. The set must also have been stored close to the ground, as humidity has had a chance to oxidize the plating behind the front panel plate. This is particularly noticeable along the bottom inch or so, where the paint has lifted, and also, to a lesser degree, immediately above the Receiver Power Supply assembly on the right side.

The set was rebuilt in 202 Base Workshop, Montreal in 1966, with three Mods being done. I have yet to check my files to determine what those modifications were, so more on that later, as the information unfolds.

Interestingly, both dynamotors were built in 1945, and since the Supply Unit was built in 1944, clearly the dynamotors were replaced at some point while the set was in service.

For the time being, I think I will be limiting myself to a slow, careful cleaning of the front panel of this Supply Unit, so it at least looks like it belongs next to the main set receiver I have been working on. I might even get this cleaning done this weekend. The Sender is currently on its way to me so if I get the Supply Unit cleaned up this weekend, I will still have something to do next weekend.

David

[David Dunlop]

Couldn't wait! I gave the front panel a quick surface cleaning to at least get all the grime off. What is left in terms of discolouration now is mostly yellowing of the varnish top coat. That I can eventually lighten with a form of very fine jeweller's rouge and I will try to match it up with the lower panel on the Receiver until I can get around to a complete refinish of the Supply Unit front panel.

The first photo is of it sitting beside the Receiver. When I cleaned the two rubber cones on the headset leads, I discovered the left one still had a large circular red stamp on it which shows up in the photos in the 52-Set manual. The right hand connector had been exposed to high heat at some time as the cone is drooping in one location. I will likely replace that cord with an NOS one I have tucked away somewhere.

The 2nd photo is of the entire 52-Set Project parts accumulation to date. Feels nice to finally be at the 60% mark for the main set pieces!

David

[David Dunlop]

I thought I might take some time at this point to document the relevant Modification Instructions for the main set Supply Unit. Over the years, I have found many wireless sets with holders for the modification cards mounted to the inner chassis, but the card is no longer contained within. If you want to know what was done to the set in terms of upgrades, this can be frustrating. The only thing you know for certain with an empty card holder is that at least one modification was performed to that particular piece of equipment, the addition of the Modification Card Holder. If no card holder is present (assuming one was not removed), then no modifications were ever done to your equipment.

Modification Instruction No. 1: This simply adds the metal card holder to the large central plate on the top of the Supply Unit Chassis. Nice and simple. See Photo 2 in Post 198 above.

Modification Instruction No. 2: Another simple one. There is a large resister (R38A) at the back of the supply that needs attention. It is located in the lower left corner, viewed from the back of the supply, mounted horizontally, directly above the 3-pin contacts for the Receiver Supply Module. The red lead on the right hand side of the resistor was prone to getting snagged between the supply chassis and the Carrier No. 4, getting the insulation rubbed through and shorting to the chassis. The fix was to take a small piece of electrical tape and secure this lead, either to the adjacent lead, or back on itself to keep it out of harms way. See Photo 3 in Post 198 above.

Modification Instruction No. 4: This is the most complicated of the three modifications that were issued for the 52-Set Supply Unit. It is a two-part modification to prepare the set for operation in Arctic conditions (read ‘Very Cold!’). At this point in time, the first part of the modification would be very hard to verify. It involved removing the grease and oil from the bearings on the two dynamotors and replacing it with lubricants suitable for cold weather operations. The second part of this modification involves the OZ4A valve located in the receiver vibrator supply module. This is a gas filled valve and for the sake of this discussion, its working conditions are very similar to those of a florescent light tube. If it gets too cold, an OZ4A will not fire properly so the receiver supply will shut down. To solve this problem, a large resister was installed in the receiver vibrator supply. It was mounted underneath the receiver supply chassis, one end soldered to the Pin-2 terminal of the OZ4A socket and the other end to a grounding ring lug, mounted underneath one of the mounting screws of an adjacent transformer located on the nearby side of the chassis. See the attached photo. The resistor in question is the large, black one; oriented diagonally, roughly dead centre in the photo. Once this resister was installed, a 6X5GT could be installed to replace the OZ4A in cold conditions and the vibrator supply would be quite happy regardless of how cold it got. I believe an OZ4A could still be used with this modification in place. Just don’t take the 52-Set camping in Alert in January.

So, hopefully, if you own a 52-Set Supply Unit with an empty Modification Card Holder inside it and you can find these changes to your Supply Unit, you now know these mods were done.

David