Wireless Set No. 52 Canadian - Project

[David Dunlop]

Sometimes the side projects are just as interesting as the main event. A good example of that is the research done to track these items down.

As with all of the parts for the Wireless Set No. 52, the above noted description for these parts is the military one, taken directly from the Illustrated Parts List for the 52-Set. If one searches the web using this description, or even parts thereof, one does not find much. Searching with the name ‘Airloc’ found on the larger Cowl Fastener Studs did turn up some illustrations of the studs and their corresponding receptacles and a general description of how they worked, and not much more.

Several styles of studs were shown and confirmation was given their prime use was in the aviation industry, where the most common studs were either slotted truss head, or slotted countersunk. The wing head styles used in the 52-Set are largely ignored.

When one actually has a complete 52-Set on hand to study and cross reference to the Illustrated Parts List, the light bulb eventually goes on that the Shakeproof Company also made similar, though smaller, wing head cowl stud fasteners, and these were used on the Supply Unit and Sender. An even closer look at the four of these on my set, after they had been cleaned, revealed a third company, Dot Fasteners, was also making these smaller wing head cowl fasteners as one time.

It took some digging, but I now know the fixed receptacles for the larger Airloc stud fasteners can be found on-line at vintage aircraft parts suppliers. The wing head studs of any size or company are still proving elusive. That just left the PINS to deal with.

The PINS are what make these fasteners work. When the stud is inserted into the spring receptacle and given the required one-quarter turn, it is the two ends of the PIN, sticking out either side of the stud that engage the slots in the receptacle and follow them down to the cups where they lock in place. These PINS are one time use only. If the stud needs to be removed for any reason, the PIN is pressed out and removed, and a brand new one put in its place when reassembled. Logic said the PINS had to be available somewhere as the studs in one form or another are still being used today. It was not until another recent search of the web that I spotted a photograph of one of these PINS, with a description of it being a ‘cross pin’ that the mystery was solved. Sticking the name ‘Airloc’ in front of the words ‘cross pin’, on the very first try, took me to a company called AIRCRAFT SPRUCE CANADA located in Brantford, Ontario and their very helpful Sales Rep, Carolyn Harris.

Carolyn pointed me to Stock Number 04-01071 in their inventory, which turned out to be:

AIRLOC Cross Pin, Steel 99785-2

See the attached photo. These are the cross pins needed for the smaller Shakeproof and Dot Cowl Stud Fasteners on the 52-Set Supply Unit and Sender.

Carolyn also took the time to mention that these two different sized Cowl fasteners have an industry standard identification across all manufacturers. It shows up in the last digit of the Airloc Part Number above, ‘-2’.

The larger cowl fasteners, as used on the 52-Set Receiver and Coil, Aerial Tuning are referred to as ‘#5’, or ‘-5’ sized fasteners. The smaller ones like the Shakeproof and Dot are referred to as ‘#2’, or ‘-2’ sized fasteners.

Overall, more needed parts for the project found and an interesting addition to the learning curve.

David

[Jordan Baker]

Great find. Aircraft Spruce Canada has some great items. I’ve always found the. To be very helpful

[David Dunlop]

Hi Jordan. Yes it is nice when you run across companies like that these days.

I was able to get the second fiddly little task out of the way on the Sender this afternoon by carefully drilling out the broken stem from the Sender panel mounting screw located directly above the BAND Switch in the upper right corner of the chassis. Even nicer than getting the stem out, was the fact that when I tested the hole with a spare screw, it went in, and came out, beautifully.

This just leaves one final, but challenging task for the Sender while it is in stripped down mode: figuring out how to reset the COUNTERS, 0/9999 ZA/CAN 4642 for the 7 – 16 MC PA LOADING Control back to read ‘0000’.

At this point, I am pretty certain the COUNTERS assembly will have to be removed to be reset. Then I will have to figure out how to keep it set at all zeros, while maintaining all its correct mechanical orientations to realign with its Tuning Coil connection when reinstalled.

On the bright side, I have a spare COUNTERS assembly from a parted out Coil, Aerial Tuning Unit to sort things out with and with the colder weather here once again, lots of spare indoor time is available.


David

[David Dunlop]

After drilling out the broken panel screw stub from the chassis the other day, I remembered there was a screw completely missing in the lower feft corner and next to it, an incorrect machine screw. I decided to check both those holes as well with proper hardware to ensure there were no surprises later on and both worked perfectly well.

There are a handful of small parts that mount directly to the Sender panel independent of chassis attachment or other parts, so I have decided to replace them now while the panel is easy to work with.

First back on today was the Data Plate. Seemed only proper.

David

[David Dunlop]

I found myself at a bit of a wall this passed weekend with the 52-Set Project. I would very much like to get on with the reassembly of the Sender and was very keen to add more bits back onto the front panel.

One of these was the large, conical, Bakelite SOCKETS, Antenna in the upper right corner. This is the main connection point of the set to the Coils, Aerial Tuning and beyond.

The problem was, I am missing two 6-32 external tooth lock washers from the mounting hardware: the two screws that are the most difficult to access when the set is in its normal upright position. And secondly, when I looked inside the Bakelite cone at the front. The brass sockets assembly way inside is a filthy mess and needs to come out for a full clean up. I eventually pulled myself back from the idea of reinstallation at the moment and will take the time to clean and source the proper missing hardware.

Won that round so far!

David

[David Dunlop]

One of the other parts I wanted to reinstall on the weekend was this one.

I have the original from the Sender and a second one, which is from a spare parts Coil Aerial Tuning Unit. Both of these, however, have had their mounting hardware over tightened when last mounted on their respective parts. The result of this, over time, is the pressure exerted by the hardware slowing pushes the material out from under the screw heads and to the left of the PLATES assembly. This has the effect of lifting the extreme left edge about 1/16-inch off the front panel face.

Both of these PLATES are dimensionally identical, but the similarities end there. The upper one in the photo is from the spare COILS, Aerial Tuning, and is identical to the one on the COILS, Aerial Tuning on my 52-Set (except that one lies perfectly flat). Both of these COILS units were rebuilt at some point post war. The original two luminous decals have been replaced with none luminous ones with white borders. It would not surprise me if these two PLATES were replacements as well. They may be prone to a lot of breakage, as they get older.

The lower PLATES is from the Sender and is very likely an original example of what CMC used on their production line.

All three are a sandwich assembly; a thick inner core with a very think white skin bonded either side. The similarities end there.

The original one is much more translucent than the other two, when they are held up to a light. The printed markings are a definite, dark black. The printing on the other two is a pale mid grey colour. The background of the original was probably a smooth clean white colour that has yellowed over time. The other two have a parchment paper kind of colour to them and although the surface is completely smooth to the touch, it has the look of very fine sandstone to it.

If anyone has a COILS, Aerial Tuning still with its original all black, luminous green decals, I would be curious to see what PLATES, Phenolic, Calibration is fitted to it.

David

[David Dunlop]

It turned out to be such a nice sunny, warm, calm day this afternoon; I could not let it go to waste. I stripped down all the varnished, chipped paint from these two KNOBS for the Sender and primed them out on the driveway.

They should be cured in a couple of days, and it is supposed to still be nice weather then, so they can then get a final coat of Gloss Navy Grey.

These KNOBS must have been refinished during the sets 1966 Workshop Overhaul. No primer was used. The core metal is cast brass with zinc plating. You could actually put pressure on the stem of each item with a thumb and finger and twist the paint off the KNOBS. I could not see any primer of any colour on the inside of the paint chips.

David