Wireless Set No. 52 Canadian - Project

[David Dunlop]

Another production detail for the Wireless Set No. 52 appears to have revealed itself this past week.

Back in Post #199, when my Supply Unit for the 52-Set had arrived, I posted a photo of it that showed an odd red circle on the left hand Drop Cord rubber Y-Socket. The circle had a blurry red bar across it. No markings at all survived on the right hand Drop Cord, which was in rough shape. Looking at working photos of the 52-Set since then, both wartime and postwar, I have noticed there is nearly always just one Headgear Assembly Type 10 ever connected to the 52-Set and it is always on the right hand Drop Cord. The left hand Drop Cord only ever seemed to get used to connect a short Jumper Cable to a Wireless Remote Control Unit No. 1 Cdn, typically situated to the left side of the set, somewhere. So, the left hand Drop Cord seems to get very little use over time.

Later in Post #213, I added a photo from the Operator’s Manual showing the factory look of the Supply Unit, in which you can see both Drop Cords have this circular marking, though still not readable.

While trying to keep busy with something related to the 52-Set Project this last week, I decided to take a closer look at my two Head Gear Assemblies Type 10 and related bits I had accumulated. The two assemblies are in good shape, but have the usual NATO Green Goop slathered all over the metal Mic Cases. Then I remembered I had found some NOS No. 2 Brown Mic Cases and cordage and dug them out. Glad I did!

In the attached photo, you can see the backs of both Mic Cases sport a yellow Circle with R.C.A. across the middle of them. The rubber Y-Plug on the cord has a silver circle on it with R.C.A. across it. So it looks like R.C.A. was supplying the Drop Cords and Head Gear Assemblies to Canadian Marconi Company for production of the 52-Set.

Not totally surprising considering the two companies were already partners in the shared ownership of the Radiotron Tube Company, but it is another detail I will have to try and preserve while restoring this set.


David

[David Dunlop]

Back in 2019, while still searching for a 52-Set, I was in touch with Richard Hankins in England regarding his Remote Receiver which up for sale at the time. It was very original with early style decals for the Tuning Dial that had the white centre rectangle with red and blue lettering and a nice No. 2 Brown finish on the case.

We corresponded briefly about it but I passed on purchasing it due to the alarming shipping costs, and then forgot about it.

While cleaning up some files today, I ran across the attached photo of the Remote Receiver Case. Note the hardware. It appears to be a slotted, thin head 1/4-inch hex bolt. I had no idea these were ever made!


David

[Chris Suslowicz]

I think the R107 used bolts like that to fix the set into the case. (Including a very long one that went from front to rear and had a tendency to shear off.)

(I can't get at my R107 to check at the moment, but I'm fairly sure they were thin headed bolts with screwdriver slots - presumably so the operator didn't need a spanner to change the valves, fuses, or vibrator.)

Chris.

[David Dunlop]

Chris.

That is fantastic news on so many levels! At the very least, it reaffirms my reputation as an Eccentric, Detail Mad Goof!

Very early on in this Project, I could not wrap my head around the data related to the hardware Canadian Marconi Company used to mount the 52-Set components into either the Carriers No. 4, or the Remote Receiver Case. All good, available photos from its time in service indicated hex head fasteners were in place. When the actual components started to arrive, sure enough, ¼-inch, 20 hex nuts and bolts were in place in all the expected locations, in different lengths.

The problem was, none of these hard facts lined up with the information in the Operators Manual, or in fact, the Tool Kit issued for the 52-Set. There is no 7/16-inch spanner or wrench provided to deal with hex bolts quickly and easily, and no complaints in this regard ever surfaced from the British during their trials of the set. Odd.

Second, in the Operators Manual, CMC points out in several locations that the set is reliable enough the Operator will never likely ever have to pull individual components for servicing, and all routine maintenance can be performed via the various removable panels and doors. The British Trials confirmed this. Where the Operator might run into conditions requiring removal of more than one component from the Carriers No. 4, CMC does warn the Operator it will be necessary to pull all three components and remove the Connector Assembly across the back of the Carriers to reinstall all components. This is a highly unusual circumstance, and yet, still no warning from CMC about any lack of proper tools for the Operator to do the job. Odd again.

Recently, I discovered that the upper hardware on my Remote Receiver was installed backwards according to a number of photos I had seen. Photos showed bolt heads to the outside, mine were reversed. When I flipped them around, I could not remove the upper receiver panel. The hex nuts and split washers stuck too far out on the inside of the case. One more thing that did not add up.

Now, two years after receiving Richards photo of his original Remote Receiver, I finally see the hardware used was a thin head, slotted hex bolt. That fits perfectly into the puzzle. In the 1930’s and 1940’s the slotted screwdriver was supreme in the average toolbox, spanners and wrenches were typically for working on things more robust than a wireless set.

A similar concept applies to the hardware used in wireless sets. Split washers seem very rare to none existent in British wireless equipment. They nearly always use a much thinner, internal toothed Shakeproof washer to lock things down. They take up less space.

The final interesting thing I have noticed with the larger hex hardware used on wartime wireless equipment is that the hex nuts are a lot thinner than their modern equivalents today.

My thought on all this latter stuff is that post war, spanners, wrenches and drive sets of various sizes became very popular tools everywhere, very rapidly, for two big reasons: speed of use and the massive increase in torque one can apply to the hardware. That probably spelled the end to the wartime, thinner hex nuts and bolts. It would become extremely easy to over torque this older hardware, rounding off the corners on the nuts and bolts and probably even shearing off a lot of bolt heads.

Consequently, here in Canada at least, whenever the 52-Sets went in for servicing, or maintenance of any kind, it probably became standard practise to simply remove and toss the factory original hardware and replace it with the more robust, modern stuff designed for use with modern, high torque tools.

Nice that Richards Remote Receiver survived in England all these years with little change.

Not so nice I now have to find a bolt shop somewhere that still stocks old style, thin head slotted hex bolts and old style thin hex nuts.



David

[Grant Bowker]

Not directly suitable but indicates that at least someone wants slots and hex heads on the same fastener...
https://www.mcmaster.com/screws/hex-...slotted-drive/
Were fasteners on the 52 set like those on the 19, often BA threads?

[David Dunlop]

Hello Grant.

Yes, a quick glance at the Web yesterday suggested there were a number of companies making modern slot head hex bolts. I fear the trick will be finding a company still making the vintage thin head versions.

The hardware mix on the 52-Set is consistent with that found on the 19-Set and very likely all other wireless sets of British origins, used by the Canadian Military. The BA Thread generally tends to be found, however, in just a few particular components. The Pocket Watch Holder mounting hardware is a classic, along with bits of the Tuning/Flick Drive Assemblies.

What I have noticed is the BA Threads are common enough they are listed in the Standard Hardware Lists compiled by the Ordnance Supply System. Interestingly, these slot head hex bolts do not show up on the Standard Hardware List at all for the 52-Set, so they must have been placed elsewhere in the system.

One thing I did find this morning is the ¼-inch ID split lock washers typically found on the ¼-inch mounting hardware today on the 52-Set Components, do not exist on the original Standard Hardware List. The much thinner, Shakeproof, ¼-inch ID internal toothed lock washer is the only one listed. That would be consistent with the idea the original hardware was beefed up with modern replacements post war, for convenience in servicing.


David

[David Dunlop]

It certainly is easy with large projects like this to lose track of what you have actually accomplished. There is a tendency to fixate on the things that still need to be done.

I have decided to step away from the major components for a while, for several reasons, not the least of which is to clear my head a bit and deal with something entirely different. Towards that end, I am going to tackle restoration of one of the Microphone and Receivers Headgear Assemblies, Cdn, Type 10 that I have for the set, One is complete and in very good shape, though yet untested. The second one is all there, also untested, but has issues, so I shall tackle it first.

The Illustrated Parts List for the Wireless Set No. 52 is helpful in that it shows the major pieces for the Canadian Headgear Type 10 and provides good written descriptions of them, but that is as far as it goes.

On the bright side, however, the FZ 256 Illustrated Parts List for the Wireless Set Cdn No. 19 Mk III and Ancillary Equipment, has very detailed exploded view illustrations of all the parts of the Canadian Headgear Type 10 covering virtually all of the little bits and pieces. You can see clearly where everything goes, and even better, all the hardware is shown, with relevant descriptions and part numbers.

The four photos posted today show the complete headgear assembly that requires restoration, and the three reasons why.

The first major problem is that somebody cut the leads off one receiver assembly for some reason. There is no sign the setscrews on the receiver have been touched, which is odd. These receivers were used in a variety of headgear throughout the war. In most instances, the leads would have a small brass ring terminal stapled to the end. The staples cut into the covering and insulation of the lead and connect with the central copper core of the lead. The two small screws on the back of the receiver would be removed and the ring terminals fitted over the screw and everything reattached. With the Type 10 Headgear, the end terminals on the leads are just brass staple sleeves about ¼-inch long. These are then slid into holes in the receiver below the two brass screws. The screws are simply backed off enough to allow the end terminals of the leads to slip all the way into the holes and then the screws tightened down as grub screws.

The second problem is the typical massive coat of NATO Green paint brushed on the microphone and which is badly chipped. That needs to be dealt with somehow.

The last issue I am currently aware of is the state of the heavy-duty oilcloth neckband cover. Years of exposure to Brylcreme and being rubbed between the back of a Wireless Operator’s neck and Battle Blouse have worn the cover down to its cloth core.

So let the games begin.


David