Wireless Set No. 52 Canadian - Project

[Mike K]

Originally Posted by David Dunlop

A new ‘longshot’ idea is these cylinders are nothing more than a spacer, or guard, to protect the tuning gear drive from getting knocked out of alignment when the coil assembly is removed from its wooden case. I say ‘longshot’ because a 2-inch piece of 3/4-inch wooden dowel would have been a far cheaper and simpler solution for this type of problem.


David

Yes I believe they are just spacers that provide some mechanical stability to the rotary inductor frame and also prevent damage to the inductor unit mount which looks like a phenolic sheet material.

[David Dunlop]

Hello Mike.

The frame work is actually 1/4-inch phenolic plates, assembled at the factory with zinc, or cadmium plated, brass brackets and hardware, another part of the design showing CMCs desire to avoid the presence of ferrous metal in the construction of these Coils, Aerial Tuning No. 2 A, at great length.

They seem to have not wanted any latent magnetism developing within these units at all costs, and I fear I am not yet wise enough to understand why. Insert “Sigh” here.


David

[David Dunlop]

I have pulled this photo up again because it shows really well the four sets of components that are fitted to the wooden case for the coil, once the coil assembly itself has been removed. In order to refinish the wooden case, all four of these sets need to be removed. These components are as follows:

1) Aerial Output Terminal - located on the upper left rear side panel. The tip of the socket assembly for it is just visible in the upper left corner of the photo.

2) Input Terminals - there are two of these fitted with wing nuts located one on each lower rear side panel. The inner brown phenolic mounting strips are clearly visible inside the back of the case.

3) Panel Mounting Brackets - three each across the upper and lower front of the case.

4) Case Mounting Plates - mounted to the bottom of the case, one each side.

It should be noted, that with the exception of the casual mention of the two above terminals in the Operators Manual, none of these IDs are official and none of these parts can be found in either Issue 1 or Issue 2 of the Parts Lists for the 52-Set. Some of the individual parts making up these items are listed, however, but not all. I guess I should also point out here that I recently ran across a few pages from an Issue 3 of the Parts lists, dated 2 January 1953. I have no idea at this point if this was a few random page updates, or another full revision.

I shall cover the removal and descriptions of these four components in the next four posts.



David

[David Dunlop]

The first component I decided to remove from the coil case once the coil assembly had been removed was the Aerial Terminal. Not because it is in the way of anything else to be removed, but for the simple reason it is the most fragile component, which sticks out too much. The two main pieces of it are also in the realm of Unobtanium should they be broken.

This item is not referenced at all in the Parts lists as a complete assembly at all, but three components of it are, as follows:

1) INSULATORS, Ceramic, Bushing, Female ZA/CAN 4596

2) INSULATORS, Ceramic, Bushing, Male ZA/CAN 4661

3) SOCKETS, Antenna, w/sleeve, No. C1 ZA/CAN 4593

The last component is cadmium plated, 1/2-inch brass hex rod, fitted on its outer end with the cadmium plated brass socket with sleeve. The inner facing end is fitted with a 10-32 x 2.75-inch cadmium plated brass rod.

A pair of .020 inch thick brown phenolic gaskets fit between the insulators and the wooden case, one each side. These were custom made for the application. I found both of these gaskets had become glued to the NATO Green paint since 1966 which was a little concerning. I found bt using a 4-inch steel putty knife at very shallow angle, the paint was thick enough I could slowly press into it to get the blade below the gasket and slowly lift it. As the gasket slowly came up, I gradually advanced the blade until the entire gasket popped free. This worked for both the inside and outside gaskets.

These three pieces are clamped to the left side of the wooden coil case with a 1/2-inch OD 10-32 plated brass flat washer, plated brass 10-32 Shakeproof washer (internal tooth lock washer) and a plated brass 10-32 hex nut. When the connection is made to the internal feed from the tuning coil assembly, a 7/16-inch OD 10-32 plated brass flat washer is slide down against the hex nut already in place, the feeder cable fitted and then a second 10-32 Shakeproof washer and hex nut added to secure the connection. I am missing the second Shakeproof washer but have a few extras in my parts supply for when reassembly takes place.


David

[David Dunlop]

This arrived today from Amazon.

When I discovered I was dealing with an aluminum plate for the front panel of the Coil, Aerial Tuning No. 2 A, I realized I had not had any aluminum primer on hand since I worked on my WIRE-5 project back in the 1970's. Back then, the 'Go To' primer for aluminum was the green Zinc Chromate stuff used in the aviation industry and I was able to source cans of it from Perimeter Aviation here in town. I was not at all surprised to discover the price of this stuff has gone through the roof since the 70's.

When checking for alternate products on the web, this product came up and caught my eye because it is a white primer, not the old green I had used years ago. When I was restoring the various cast zinc knobs and handles on the rest of the 52-set a few years ago, I had to find a correct primer for working with zinc or galvanized items and the product I found was also white. So I will be using the same process for the front panel of the tuning coil. A first coat of the white aluminum primer. let is cure and give it a coat of standard grey primer and then the top coat.

Just a can of xylene to track down now and I will be good to go for spray painting down the road.


David

[David Dunlop]

The six Front Panel Mounting Brackets are another undocumented item in the Parts lists for the 52-Set. They are made from 1/8-inch thick by 1/2-inch wide, cadmium plated brass bar stock, cut into 1.5-inch lengths. These are them formed to create a 1-inch long bar with a 1/2-inch tab folded at 90 degrees at one end. Centred along the one inch base are two 11/64-inch holes, themselves centred 7/16-inches apart. The small tab is centre drilled and tapped to accept the cadmium plated RH slotted brass 8-32 x 3/8-inch panel mounting screw.

All six Front Panel Mounting Brackets are identical in their mounting to the wooden coil case with a pair of cadmium plated, 6-32 x 3/4-inch RH slotted brass machine screws, brass Shakeproof washers and brass hex nuts. If your Coil, Aerial Tuning No. 2 A has never been overhauled, or rebuilt, you will find once all the brackets had been installed, the hex nuts were secured with a dab of red lacquer. The one slight exception to the mounting process is found with the bracket in the lower front right corner of the coil case. This bracket has an additional brass fitting attached to it as part of the grounding arrangement for the aluminium plate front panel of the completed tuning coil. This fitting will get some separate coverage later, but since one end of it is also connected to the special front end machine screw for the right side Mounting Plate, these Front Panel Mounting Brackets need to be removed now to gain access to the Mounting Plate hardware later.



David

[Barry Churcher]

David, Xylene is available at Princess Auto for $14.99. I just got some there.
Barry