Wireless Set No. 52 Canadian - Project

[David Dunlop]

Another generalized title to cover off the following three, related components in the Wireless Set No. 52 Receiver.

BODIES, Shields Valve, 1-5/8 inch dia. x 2-7/8 inches long, No. C1 ZA/CAN 4279

This item is made of nickel-plated tin, the upper end of which has been rolled back in on itself forming an inner open ring. Inside this ring, a felt washer has been cemented in place. This washer has a ¼-inch square cross section, a 1-inch ID and a 1-3/4 inch OD. This felt ring rests on the shoulder of the valve and when the Shield Body is fully seated in its BASE, the Valve will be fully seated in its Holder.

As per the example of this Shield Body in the first photo, the nickel plating can often wear off the tin externally. Not sure why, but the insides and the upper and lower ends of the outer surfaces that are covered by the Base and Cover, stay in pretty good shape. I have considered redoing the nickel-plating on these Shield Bodies but that would mean soaking the inner felt washers in a solution loaded with nickel ions that would stay in the felt once dried out and I am not sure that would be a good thing for the proper operation of any valve in the future.

COVERS, Metal, Shields Valve, 1-11/16 inch dia. x 1-3/4 inches long ZA/CAN 4233

These are the commonest Covers found in the 52-Set Receiver, with a single side slot for accommodation of a Grid Cap Clip lead if needed. They are made of a slightly heavier gauge of zinc-plated steel, for some reason. An example is in the second photo.

BODIES, Shields Valve, 1-5/8 inch dia. x 2-5/32-inches long, No. C1 ZA/CAN 4280.

This Shield Body was designed solely for use with the 12Y4G Valve used in the V2B, Noise Limiter in the receiver. This is a horizontally mounted valve found on the lower left corner of the rear chassis panel, directly behind the vertically mounted V1G Valve. Since clearance needed to be provided for the Wireless Operator to reach in and service/replace the V1G Valve, sufficient space was needed behind the V1G Valve to do so. Consequently, the standard Shield Body was shortened in length. This meant there was no easy means for the full shielding assembly of this horizontally positioned valve to be physically locked in place and there was the risk of the Shield Body vibration loose. Consequently, the solution Canadian Marconi came up with was to solder the Shield Body into its Base. In the third photo you can see the red lacquer markings from the factory on this solder work. The V2B Valve is an annoying valve to have to work on in this receiver. Tricky to remove from the shield and even harder to line up blind with the Holder to put it back in place.


David