Wireless Set No. 52 Canadian - Project

[James D Teel II]

Beautiful work as always.

[David Dunlop]

Thanks, James. I am happy I can still at least muddle along.

Today I got the last two front panel mounting brackets cleaned, zinc plated and reinstalled in the upper corners, so I am now finished with that bit, but still have a little new research to sort out, hopefully in the next week or so.

In the meantime, I plan to work on the two Aerial Input Terminals, located on the lower rear sides of the case. Both seemed OK when I disassembled and removed them last year, but it's time for a closer look.


David

[David Dunlop]

I got the right side Input Aerial Terminal disassembled cleaned and re-plated this afternoon. The main component of this assembly shows up in the Master Parts List as:

STUDS, Brass, Special, ANF 10-32, 1-21/32 inches long, No. C1 ZA/CAN 8048

It is machined from 1/4-inch brass bar stock and once the wing nut is fitted, the end of the threaded shaft is mushroomed slightly to prevent loss of the wing nut. It would have been easier to deal with the shaft being drill through and a small D-Ring fitted, as you have to carefully press this stud assembly out of the brown phenolic resin plate it is fitted to in order to get the entire assembly free from the coil case.

I discovered the rear edge of the resin plate showed signs of the bcd saw blade bucking when the plate was cut, leaving some light tan marks on the edge. A thin coat of clear nail polish reduced the visibility of these marks by about 50 % so I was pleased you can still notice the damage but not so glaringly any more.


David

[David Dunlop]

I was able to reinstall the right side Aerial Input Terminal last evening and once the Stud assembly with its captive wing nut was back in place, made an interesting discovery.

I had assumed the mushroom effect applied to the tip of the shaft the wing nut moves on was simply achieved by a sharp rap with a hammer. However, as you can see in the photo of this assembly back in place, the newly cleaned and re-plated tip of the shaft revealed it had been struck with a small cross punch to achieve the mushroom effect. I was pleased another little detail finally came to light...literally.

Hopefully, I will be able to clean, re-plate and reinstall the Aerial Input Terminal on the left side of the coil case today.


David

[David Dunlop]

A productive afternoon today after all the errands were out of the way.

The left side Aerial Input Terminal assembly was stripped down, cleaned and re-plated. At the start of this I cleaned and checked the end of the stud behind the wing nut, and sure enough, it also revealed the mark from a cross punch used to mushroom the end of the stud.

When this terminal assembly was reinstalled on the left side of the coil case, I realized the only item left to deal with was the large Aerial Output Terminal located on the upper left side rear corner. I pulled it out of storage to see what work was required on it and was pleasantly surprised the metal work on it was nickel plated and in very good condition. A quick disassembly and cleaning and I was able to reinstall it as well. That just leaved three sets of hardware to clean and re-plate for the coil case and those can wait until I deal with the now pending work on the actual front panel of the Coil, Aerial Tuning No. 2 A.

That should be fun.


David

[David Dunlop]

Apart from four different sets of coil case hardware that need to be cleaned and have a new coast of zinc plating reapplied, the next major step in restoring this Coil, Aerial Tuning No. 2 A has to be the removal of the front panel from the coil chassis assembly, so that it can be stripped down of old paint, repainted and new luminous decals applied. This part of the project comes with some trepidation. The attached photos in this post are all of my spare parts coil front panel, which spent enough time in its life in a damp environment that its tuning/tracking assembly seized up completely and broke.

Once this panel is removed from the coil chassis assembly, there are only two parts still attached to it: the Tuning Counter assembly, and just under it, the Screw, Special, Brass post that forms the basis of the locking assembly for the tuning control. There is a large reinforcing plate fitted over the drive shaft of the counter. Two large spot welds secure it to the front panel and two of the three mounting screws that fasten the counter to the back of the front panel pass through the lower portion of the reinforcing plate. The third mounting screw sits just above this plate on the panel. When the tuning knob is in place, the reinforcing plate is largely obscured. The reinforcing plate prevents the front panel from flexing when the coarse tuning lever has been extended from the front of the tuning knob and can act as a lever which might otherwise bend the tuning shaft out of alignment.

When I was restoring the Sender, I had to remove a pair of these Counter assemblies from its front panel and the hardware all came free very easily. I have tried several times to remove these same item from this coil front panel with no success at all. Since those attempts, I have subsequently discovered the coil front panel is aluminum plate, not steel like the Sender front panel. I am now thinking that electrolytic reactions between the aluminum, brass and zinc, in conjunction with the dampness the coil was exposed to, may have fused this hardware solid. In addition, the hardware holding the Screw, Special, Brass in place is alarmingly tiny stuff: 2-56 zinc plated brass hardware I believe.

I am hoping I am correct about this spare parts panel and that the hardware will pop loose OK on the front panel for my working coil assembly, but it is definitely a concerning task ahead.


David

[David Dunlop]

Time to back track a little.

Back on Page 37, in Post #1097, I hd commented on finding numbers stamped onto the two phenolic resin side plates and bottom plate of the coil chassis: four digit numbers in blue ink. This was present on nothing coil chassis I have on hand and the three numbers on each chassis were matched sets. I hd assumed at that time these were possibly production control numbers, but looked rather sophisticated compared to the large hand written similar numbers found on the main component chassis of the 52-Set.

Well, when looking at the rear of the front panel from my parts coil assembly today, I noticed another faint four digit number, hand stamped in blue ink, in the upper right rear corner of the front panel, just beside a small circular Canadian Marconi Company inspection stamp with the number ‘686’ inside the circle. These markings bracket the two mounting holes in the front panel for the Plates, Phenolic, Calibration. When I checked this number ‘8798’ with those found earlier on the three coil chassis plates, they all matched. Interestingly, the assigned Serial Number for this coil assembly on its Data plate happens to be ‘8963’.

The dilemma is that the other coil assembly I have bears the stamped number ‘3978’ and that coil assembly is missing its data plate, and adding more mud to the waters is the fact serial numbering for the 52-Set started at ‘5001’. And the rear side of that coil front panel has been wiped clean at some point, probably during a workshop rebuild.



David