Wireless Set No. 52 Canadian - Project

[David Dunlop]

The mid-level shelf plays into this saga at this point so I thought I would start there with a photo of the three components mounted to it. While taking this photo, I noticed through the lens, the trace of part numbers along the face of the shelf, directly below the middle and rear components. A check of the photos Jerry Proctor posted of the 52-Set Supply Unit on his website confirmed these numbers should have been there, along with similar numbers stamped onto the side of the front component and the one directly above the middle one. Large black Roman Font with a heavy overcoat of varnish. All these had been very carefully cleaned away. Why, I wonder.

From left to right, these three components on the shelf are:

L28A, the AF Choke (Smoothing Filter) for the MG1A LP Rotary Transformer.

L26A, the RF Choke (Smoothing Filter) for the MG1A LP Rotary Transformer.

S11A, the Dynamotor Input On/Off Switch relay again.

The second photo goes back to the underside and the shelf again and the visible hardware. Note the small BA screw securing the L26A RF Choke above it. This screw, and two others in the entire Supply Unit, are the only ones I can find that still retain their factory original internal toothed Shakeproof washers. Virtually every other Shakeproof washer has been replaced with much larger thickness external toothed washers. I checked both editions of the Parts Listings for the 52-Set and these heavy-duty external toothed washers are not listed at all. They do not show up in any of the other 52-Set components either.

One might think that is no big concern, but take a look at the third photo today. I have slid the Cases, Metal C1 for the Receiver Vibrator Supply back onto its tray in the Supply unit, carefully levelled it and slid it in as far as it can go. It hits the front left hex nut securing the large L28A AF Choke on the shelf above and stops dead! That external toothed lock washer is far too thick. If you look carefully at the hole in the hex nut, you can see the end of the machine screw is set back in the threads of the hex nut. It is not flush with the face of the nut. In fact, the setback is suspiciously similar in depth as the amount of space needed for the Cases to clear the hardware completely. The only way you can get the Cases to go all the way down its tray is to apply a lot of downward force on it to flex the front section of the tray down far enough to get the leading upper edge of the Cases under the hex nut. As soon as you release that downward force, the Cases is stuck and the only way to get it all the way into the Supply Unit is to block the front of it with a piece of wood and pound it home with a mallet. Remember the big long gouge along the top of the Cases in the last photo of Post #765?

I know that the upgrade kits for the two Rotary Transformers in 1945 included new sections of wiring harness. This new harness was all done in solid colour plastic sheathed wire, as opposed to the factory original white cotton and trace style of harness. Most of the Supply Unit would have to have been disassembled to do all that replacement work and from the wiring part, it was done very well. The looms that had to be disassembled were all very neatly relaced when finished. You can see a mix of all original, all new and blended throughout the Supply Unit. What I do not understand is why they replaced all the Shakeproof washers that had a great international reputation for being very reliable electronics hardware, with these big, external toothed washers that did not fit properly, when all the original hardware was right there in front of them in the first place?!? Crazy!

Time for some Egg Nog!


David