Wireless Set No. 52 Canadian - Project

[David Dunlop]

The first thing I noticed once I had successfully removed the Cases, Metal C1 from the Supply Unit was a small piece of manila sheet sitting near the back of the tray the Cases rests in, with one side of the manila heavily varnished. The piece of manila is 1-3/4 inch x 2.0 inches. As I was lifting it out of the tray, I spotted a small machine screw sitting in the right, rearmost depression of four stamped into the floor of the tray, in the back half of it. These four depressions form legs, which are spot-welded to the chassis frame of the Supply Unit to secure the tray in place. This screw is a 6-32 x 3/8-inch machine screw. As I was removing it, I spotted straight away that it had come from the right rear end of the tray assembly. The back part of this tray is stamped from a thicker piece of sheet steel and forms the mounting bracket for the brown phenolic plate the holds the three Banana Sockets that accept the corresponding three Banana Plug Power Connectors from the Receiver Vibrator Supply. The sockets are designed as a loose fit on the phenolic board to allow them to easily line up with the plugs when the Vibrator Supply is slid into the Supply Unit and locked in place.

There was no sign of the hex nut or internal tooth lock washer for the loose 6-32 machine screw, and I do not recall ever finding them in the Carriers No. 4. The washer fits under the head of the screw at the front of the tray assembly, but the only way I can see to get the hex nut installed is to slide it in place in a thin was wrench, like those used for working in ignition timing points. Access is completely hidden by the right rear Supply Unit chassis angle. That ought to be fun.

Turned out the manila sheet came from the upper left side corner of the Cases, Metal C1 as seen in the photo I posted previously. It was varnished in place there to prevent any possible shorting contact between the Cases and the Negative Low Tension Brush Holder assembly of High Power Rotary Transformer MG-2A, when the Cases, Metal is in place.

Photo 1 shows the manila sheet and machine screw as found.

Photo 2 is a shot looking directly down the tray assembly from the front of the Supply Unit. It is a pretty good view of the rear phenolic panel holding the three Banana Plug Sockets and you can see the hole on the rear right end where the machine screw fell out. Also, on the tray floor at the very back you can just see the shadow in the dust where the manila sheet was resting, and the four, stamped depressions/feet for the tray can be made out just forward from that shadow.

The final Photo shows the Negative Low Tension Brush Holder of the HP Rotary Transformer, which would be at risk of shorting without the manila sheet on the left side of the Cases, Metal C1. And also in this photo is a good view of the modification to the resister terminal I mentioned earlier, where it had to be wrapped in electrical tape to better insulate it.

David