Wireless Set No. 52 Canadian - Project

[David Dunlop]

These Clips are found on a number of wartime Headgear. What caught my eye with them on the Type 10 Headgear is just how well thought out the design work was on this equipment.

When these Clips are used on Headgear with the round, chamois Ear Cushions, there is a significant amount of free space between the Ear Cushion and the Clip. As you can see in this photo, with the oval style Ear Cushion, the right angle bend at the top of the Clip just slips nicely over the top rim of the Ear Cushion. That kind of attention to detail always impresses me, even more so when it comes from outside the modern computer world.


David

[David Dunlop]

I am giving some thought to restoring this Connectors assembly next in the 52-Set Project. That is a bit of a concern as this particular part is the lifeline for being able to operate the set and I would hate to unscrew the cover on it and have the innards fall apart on me.

From the outside, there does not seem to be much wrong beyond the usual cleaning.

If you back up to the last photo in Post #705, you will see the hardware set in the upper left corner of the front cover plate has been missing since I acquired the Connectors. Having removed another of the hardware sets, I found it to be a 4-40 x ½-inch RH machine screw with matching flat washer. I still had a few such machine screws available but was out of 4-40 flat washers, so borrowed a reasonable replacement washer to at least finish off this corner until I order in more washers. Fortunately they can still be had for around $5.00 Cdn per 100, which should do me a very long time.

According to the Illustrated Parts List, the raised letter identification caste into the top of the Connectors should be topped with white paint. I can still see traces of it and the lettering is in excellent shape, so that should be relatively easy to bring back to life.

At the lug end, the cotton cording wrapped around the Negative Cable Lug has broken and started to unravel, so will need to be replaced. I think there is a wrap of black, cloth electrical tape just under the cotton, so I may need a new spool to hockey stick tape for the toolbox. I think I am out of that as well.

Where this Connectors assembly gets interesting is in regards to the colours of the two cables. The Parts Manual states a red cable for the Positive line and a black one for the Negative line. The black one is alive and well, but from what I can determine so far, there is no trace of a red colour to the Positive cable at all. The present visible length and the fuzzy bits that provide a glimpse into the interior of the cotton loom all show what is now a dirty tan/white cotton. Adding to the mystery is the presence at the lug end of the Positive line of a red, paper tape wrap, very similar in size to the paper tape Butcher Shops use for wrapping brown paper packages of meat. So if any red colour on the Positive line still exists, it is likely going to be found inside the Bakelite body of the Connectors.

If no red cotton looming shows up inside the Connectors, I wonder if these Connectors were rewired at 202 Workshop as part of a normal 52-Set overhaul and in the 1960’s they were using tan, or white, loomed cable for the Positive lines and marking them with a red tape at the lug end to comply with the descriptions in the manuals?

Maybe two versions of these Connectors now exist: factory originals still in red and black cotton looming and overhauled ones in white and black.


David

[James D Teel II]

I think the latter hypothesis is probably correct. It could also be that at the time of manufacture no red wrapping was available so the positive was just marked at the end. We never know.

[David Dunlop]

Hello and Good Afternoon, Mr. MacMillan! Nice to hear from you again.

The Type 10 Headgear has been an interesting little side project to work on. Back in the 1970’s and 80’s, I never saw too many of them. I knew they were made with aluminum cases for the microphones and the story at the time was they had been made for tank crews because the Bakelite No. 7 style microphones were too easily broken. End of interest/information, but I suspect the breakage issue for the No.7’s was probably quite real. I was quite surprised, when I opened the first one up to discover it was caste aluminum, not the stamped sheet I was expecting. VERY robust indeed compared to the No. 7 Bakelite mics.

I have limited, dateable documentation covering the Type 10 Headgear, but what I have, from newest to oldest is as follows:

15 Feb. 1945: FZ 526 Issue 1 for the 52-Set

01 Oct. 1944: FZ 256/3 Issue 1 for the 19-Set

Oct. 1944: The Philco publication for WS 19 Mk III Cdn Installation Instructions for Truck and Ground Station. This was clearly a rush publication because the headgear illustrations in it all clearly have No. 7 Mics but are identified at Type 10 Headgear.

08 May 1944: The 52-Set Operators Manual, which has an actual photo of the headgear.

The latter document is interesting since it would have been the reworked version of what had originally been intended as the Operators Manual for the Wireless Set No. 9 Mk II that Canadian Marconi was targeting delivery for in late Winter or early Spring 1944, and which got delayed with British approvals and name change. The original manuscripts were probably written, proofed and delivered to the printers in late 1943 to keep things on schedule, so the Type 10 Headgear had to have been available sometime earlier in 1943 for CMC to have taken advantage of it with what became the 52-Set.

Besides the two complete Type 10 Headgear I have for my 52-Set that are marked top to bottom by Philco and RCA (the RCA markings of which match up with the ones on the Supply Unit Drop Cord photos in the 52-Set Manual) I also have another Type 10 with no RCA stamps, or Philco on the receivers for that matter. No. 2 Brown microphone case with just a yellow C-Broad arrow under the D-ring on the back. Two other sets are devoid of any markings at all and the microphone cases have been NATOed.

My thoughts on all this are that RCA was probably the prime, or sole, maker of the Type 10 Headgear and were approached by Canadian Marconi to supply the needed amount for their 52-Set Contract. Since these types of wireless accessories are never serial numbered, maybe as a means of production control, RCA elected to stamp parts with their logo in the production line to help them identify and separate the Headgear that were to be used to fulfill the CMC Contract?

Either that, or the executives on either company knew each other in the business and social circles well enough the RCA Executives decided to do it just to poke the bear?...

So perhaps today, some Type 10 Headgear survive that were originally part of the 52-Set Contract and many more are out there which were incorporated into other wireless equipment from 1943 (?) onwards.


David

[David Dunlop]

Indeed, James. But then what's Life without mystery…

David

[David Dunlop]

I decided to clean up the large Bakelite socket assembly on the Connectors, Twin No. 17 this afternoon. I was thinking this would also give me an opportunity to open the assembly up and see if any red colour remained on the small section of Positive Cable inside the assembly. However, as soon as I had unscrewed the socket assembly from the front of the Supply Unit, I realized that was not going to happen since I could clearly see the cotton windings from the terminal sticking out of the socket assembly about one eighth inch. But I got a break anyway.

As you can see in the photos today, particularly the third one, there is a roughly two-inch section of the Positive Cable that faced towards the Supply Unit that shows the remains of a red colour. Finally! I feel good about that find.

These three photos show the uncleaned socket assembly and the last one I have started cleaning the oxidation off one of the brass sockets that accept the large banana plugs on the front of the Supply Unit.


David

[David Dunlop]

These last three photos today show the Socket Assembly after cleaning and polishing. The dirt is all gone and about 80 % of all the scratches, which is a major improvement. Even the ‘LT’ and the ‘ 12 VOLTS’ caste into the upper and lower parts of the front face are easier to read now.

Once the dirt was cleaned off the white ID Printing, it turned out to be in very good condition and will not require any attention.


David