Wireless Set No. 52 Canadian - Project

[David Dunlop]

I had to do some thinking before proceeding with the next step of reinstalling the two PA LOADING Tuning Knob assemblies. These consist or two main assemblies.

The first to go back on to the Sender is the PLATES, Metal, Dial Locking. This is an interesting little design that is nothing more than a tapered piece of sheet metal, split down the centre, with a large hole at the wide end and a split cone fitted to the narrow end. When in place on the front of the Sender, the large hole accepts the central brass core of the KNOBS Assembly used to turn the tuner it is fitted to. The small end of the PLATES, with the split cone, drops over a threaded pin and a burled nut screws down over the pin and split cone. As it does so, the two halves of the cone get pulled closer together. This in turn, steadily reduces the diameter of the large hole surrounding the brass core of the KNOBS until it locks it from any further turning.

The problem with the two PLATES assemblies on my Sender was the hostile environment they had been sitting in had eaten away a good portion of the original factory zinc plating, and the remainder had turned near black. If I went with a full re-plating of the zinc, these assemblies would have looked virtually unused and would not fit in well with the overall plan for the Sender front panel: a set that had been a working set, but well cared for in its service life.

I then remembered the Coil, Aerial Tuning for the 52-Set also uses this PLATES and KNOBS arrangement and had a look at it. It had the exact look I wanted. Lots of zinc plating still on the PLATES but wear patterns evident that created lighter and darker regions on the metal. I decided to try a quick, flash plating of these two parts rather than the usual one or two hour process. I had noticed on the other parts I had plated that after about 15 to 20 minutes, you could really notice the zinc starting to build up on the metal I was working with, while still seeing lighter and darker spots where the rate of plating was different. What I came up with was exactly what I was looking for and a very close match to the PLATES on the COILS, Aerial Tuning panel.

Next will be restoring the two KNOBS for the PA LOADING assemblies.

David

[David Dunlop]

I was able to clean and refurbish the KNOBS, Phenolic, Fluted with Crank for the 7 – 16 MC PA LOADING Dial last evening.

The fold out crank portion is all brass, and I suspect originally was in a black anodized finish. When looking at the central brass spring clip assembly that locks the crank in either its open, or closed, mode, I could see the remains of the black anodized finish on the underside of it. Over years of use and cleaning, this finish wars off and ends up being replaced with several layers of semi gloss, or gloss, black enamel paint, which invariably chips all over the place.

I went with cleaning all the remaining paint off the parts and redoing them in a semi gloss black enamel that blended in quite nicely with the black phenolic knob. I noticed this morning, one small run in the paint on the outer surface of the crank, but I should be able to buff than down in a couple of weeks, after the paint has fully cured.

Now that side is done, I will get going on the right hand assembly for the 1.75 – 8 MC PA LOADING Dial.

David

[David Dunlop]

Here are three photos of what the KNOBS, Phenolic, Fluted looked like prior to cleaning them up.

David

[Bruce Parker (RIP)]

Originally Posted by David Dunlop

Here are three photos of what the KNOBS, Phenolic, Fluted looked like prior to cleaning them up.

David

Dammit man...YOU HAVE TO SHOW THE CLEANED UP ONES!!!!

[David Dunlop]

Your Wish is my Obligation, Bruce.

Here are three photos of the KNOBS cleaned and polished, but with the brass Crank assembly not yet re-paintd.

David

[David Dunlop]

Here is a photo of the Sender with both KNOBS, Phenolic, Fluted assemblies cleaned, re-painted and reinstalled.

Now I have to do some more research into the remaining black phenolic knobs on the Sender. Mainly having to sort out the 'glow in the dark' stuff originally applied at the factory.

David

[David Dunlop]

Something I have been meaning to get down in writing for quite a while now, and while I have been mulling over a closely related painting subject in my head, decided this was as good a time as any to get my thoughts and observations written down and out of the way.

Designing and building anything as complex as a wireless set, at any time, is a major undertaking, compounded even more so during wartime because of the increased likelihood of unavailable, or disrupted parts supply chains. Efficient production, however, remains pretty much at a high importance level.

An assembly line has to be designed with the highest level of efficiency, in order to keep the cost of production as low as possible, thereby optimizing profits, without sacrificing quality of the product being manufactured. That is where the Production Engineering Department of a major company like Canadian Marconi Company, earns its keep. Time, space, human resources and parts cannot be wasted. A line must flow as smoothly and logically as possible. With a minimum number of steps.

One of the things that puzzled me for a while was wartime and later photographs of 52-Sets where various parts on the front panels of the sets appeared colour mismatched to the majority of the set. I was already aware that varnish was used on the front of a wireless set to protect the water transfer decals applied to the front of it, and that most, if not all of these varnishes discoloured over time. Some more rapidly than others. My assumption, therefore, was that from time to time, parts on the front of a set would get damaged, requiring replacement. These brand new parts would be installed and having been wrapped up in a box for a while, would not show as much discoloured varnish patina as the rest of the set, so stood out in photos. But then I started to notice it was always the same large parts that stood out, these being typically the round Covers on the Blower Motors, the Access Door on the Sender and the front plate of the Receiver Vibrator Supply section of the Main Set Supply Unit. That observation made no sense to me at all initially.

Then I noticed something. None of these parts have water transfer decals on them. There was absolutely no need for them to be varnished. That would be a complete waste of time, workstation space, varnish and manpower. The most efficient production of those parts would simply have been to construct them, paint them Gloss Navy Grey and then either have them individually packaged as part of the required Spare Parts quota for the contract, or be bulk packaged for delivery to the assembly line at a specific installation station. Front panels, and any other part with water transfer decals would have been painted Gloss Navy Grey, had decals applied, any finishing work added and then been varnished before either packaging as spares, or headed to assembly.

On taking a closer look at all the 52-Set panels, and 19-Set panels. I have available at this point, I noticed several other smaller parts that match up with this type of assembly line flow.

- HANDLES, No. 72:

The large square handle on the centre dials to move quickly between the two preselected Flick Frequencies. 6 of 7 are original Gloss Navy Grey. One has been varnished.

- HANDLES, No. 80:

The small Flick Levers to the right of each dial. 7 of 10 are original Gloss Navy Grey. Three are varnished.

- KNOBS, Metal 10-32 thd No. C1:

The round push/pull knobs for getting the components in and out of their carriers. 9 out of 11 are original Gloss Navy Grey. Two are varnished.

So based on these considerations, if one had a brand new out of the box 19-Set, or 52-Set, there would be no colour differentiation at all across the front of the set. Over time with no overhauls and gracious aging, patina would develop on all varnished parts, whereas the above noted items would remain factory original Gloss Navy Grey.

Consequently, with the restoration underway with my 52-Set, all decaled parts will be reasonably matched to a slight patina shade of grey and these noted parts would be done Gloss Navy Grey. You can see the start of this plan on the Sender front panel already, where the round COVERS for the Blower and the two KNOBS Metal are Gloss Navy Grey. Once I had used the Access Door to match the panel paint to the patina I was looking for, I had intended to continue polishing the Door back to its original Gloss Navy Grey, but when looking at some of the original photos when it arrived, I noticed one could see the correct grey on the COVERS still showing, but the door matched the rest of the front panel, so I have decided that exception will serve to make the rule and also maintain another small bit of the Sender’s history.

David