Wireless Set No. 52 Canadian - Project

[David Dunlop]

This amazing piece of equipment arrived safe and sound in this mornings Post, complete with its cotton bag of mounting hardware. Its a heck of a lot larger and heavier than I expected. I have only ever seen photographs of one in various wireless manuals over the years with absolutely no reference of scale to go by.

A number of interesting questions have arisen since its arrival, however.

I know production of this item did not start in Canada until sometime in 1941 and it was probably a direct copy of the British version. I have only ever seen photos of Canadian ones made by RCA Canada Limited and either bearing no date, or any of 1942 to 1944. This one is dated 1944, which ties in nicely with my 52-Set, but it was manufactured by Rogers Majestic Limited, which I believe was based in Montreal. It shows a Product Code of “R M SA 3897” and a Serial Number “C253”. So the first question is whether Rogers Majestic was brought onboard to augment the production of these switchboards, or did they take over completely from RCA Canada to allow them to focus on other wartime production?

Second puzzle is this switchboard is identified as:

SW/BD CHARGING NO5C MK I

I never knew a Mk I ever existed until now and am now wondering what exactly changed in the design to warrant the Mk I status?

The other interesting bits are a 1/4-inch C-Broad Arrow stamp and possible part number stamp for the wooden frame on the lower right mounting post and the larger 3/4-inch C-BroadArrow stamp on the centre bottom of the wooden frame.

There is the remains of a piece of tape that was once over the ID info for the two Charger No. 2 terminals on the lower right and the panel markings areall stencils in either white or yellow paint. The yellow seems to focus on the four main switches, the rest being white.

Lastly, the cotton bag for the mounting hardware was made by The Canadian Bag Company Limited in Montreal.


David

[David Dunlop]

Last evening, I did a quick test on the glue residue left on the lower right side of the front panel and it look like it will remove OK with a little careful work and soaking with a glue solvent I have on hand.

I also started some online research on anything I could find about these switchboards, and in particular anything about the MK I Model. Surprisingly, I got a hit from the MLU Forum regarding the Week 37 Wireless of the Week Series Bruce Parker had put together several years ago. Week 37 covered the Switchboard Charging 5C Canadian and in it was a post from Jordan Baker who had run across a photo of a 5C MK I, Serial Number C183, also a 1944 product of Rogers Majestic. The comments back then suggest this variation was intended for the 19-Set HP and the 52-Set as both were rather power hungry wireless sets, and it was noted a new inboard pair of terminal posts were added on the upper portion of each side. The left set are marked, BATT, NO 1, CHARGE. The pair on the right BATT, NO 2, CHARGE. Upon a closer inspection of my switchboard, I now noticed where these additions were located, but the upper terminal post on each side is missing. Clearly the next step will have to be removing the plywood rear cover to see what has been going on with the wiring. I am hoping the terminals were simply removed, but not the related wiring.

In the meantime, I remember a Forum Member a few years back was parting out a Switchboard Charging 5C. If anyone has one being parted out, please get in touch with me. I suspect even a British one will have identical terminal post assemblies.

Be nice to confirm exactly why these two new sets of terminal posts were added and how they function. I have seen wiring diagrams for the original version of these switchboards, so there must also be ones issued for the 5C MK I.


David

[Chris Suslowicz]

Originally Posted by David Dunlop

Last evening, I did a quick test on the glue residue left on the lower right side of the front panel and it look like it will remove OK with a little careful work and soaking with a glue solvent I have on hand.

I also started some online research on anything I could find about these switchboards, and in particular anything about the MK I Model. Surprisingly, I got a hit from the MLU Forum regarding the Week 37 Wireless of the Week Series Bruce Parker had put together several years ago. Week 37 covered the Switchboard Charging 5C Canadian and in it was a post from Jordan Baker who had run across a photo of a 5C MK I, Serial Number C183, also a 1944 product of Rogers Majestic. The comments back then suggest this variation was intended for the 19-Set HP and the 52-Set as both were rather power hungry wireless sets, and it was noted a new inboard pair of terminal posts were added on the upper portion of each side. The left set are marked, BATT, NO 1, CHARGE. The pair on the right BATT, NO 2, CHARGE. Upon a closer inspection of my switchboard, I now noticed where these additions were located, but the upper terminal post on each side is missing.

I suspect they were never installed. There are differences between your switchboard and the ones I've seen and yours appears to be for field use with two charging sets, rather than permanently installed in a wireless vehicle.

Clearly the next step will have to be removing the plywood rear cover to see what has been going on with the wiring. I am hoping the terminals were simply removed, but not the related wiring.

It looks as though the positive terminals for the charging (independent of the switch settings) were deleted, and the board re-marked for two charging sets rather than a single charging set when static and "Vehicle Dynamo" on the move.

None of the switchboards I have seen have a rear plywood cover - an indication that they were fitted to a vehicle with non-conducting walls perhaps, whereas this one was for use on the ground and stray bits of metal might short it out if it was unprotected?

In the meantime, I remember a Forum Member a few years back was parting out a Switchboard Charging 5C. If anyone has one being parted out, please get in touch with me. I suspect even a British one will have identical terminal post assemblies.

Almost certainly the same.

Be nice to confirm exactly why these two new sets of terminal posts were added and how they function.

My guess is they are simply wired in parallel with the battery terminals, and the positive terminals were removed (For safety?) when the design was adapted for use out of the vehicle.

I have seen wiring diagrams for the original version of these switchboards, so there must also be ones issued for the 5C MK I.

Optimist!

Best regards,
Chris.

p.s. Now I know what those bits of mounting hardware are for (and need to get some) - they probably fitted to the underside of the radio table (or to the vehicle wall) so that the "spare" switchboard could be stored out of the way when not required. (The vehicle one would be permanently wired in.)

[David Dunlop]

And the plating of hardware and reassembly begins.

Just the two easy parts back on so far but already I have discovered the need to carefully ream out excess paint from all the hardware holes before reinstallation of parts, especially the smaller items. This hardware is all brass and the smaller it is, the more likely I will damage the hardware trying to force it though holes clogged with excess paint. Drill bits work very well at this.

Also was able to get a short time exposure shot of the two new decals on the front panel glowing in the dark.


David

[David Dunlop]

I was able to get a few more pieces for the front panel zinc plated today. Hoping to get at least one put back tomorrow.


David

[David Dunlop]

Managed to get the Tuning Counter Assembly reinstalled on the front panel this morning and keep it held at the "0000" mark in the process.

Now the really frustrating part awaits my attention, getting the front panel mounted back on the chassis assembly working with stubby hardware and fingers in VERY tight quarters. I hope I have enough wine to celebrate any successes.



David

[David Dunlop]

This next reassembly step is one I did not fully understand, or appreciate , when I was disassembling this component last winter. It simply involves installing the two small screws in the first photo through their holes in the lower front panel, into the two heavy duty brackets shown in the 2nd photo. When this is done, the front panel is then held securely in place on the Coil Chassis assembly with the main mounting hardware holes (two vertical rows of three sets of hardware) are perfectly lined up Again, see the 2nd photo to see what I am referring to.

The space behind the two end angle brackets into which all this hardware fits, is extremely limited and full of other hardware. You need both hands completely free to work with each hardware set of screw, Shakeproof Washer and hex nut. See the 3rd and 4th photos in this Post. I am impressed the Designers thought of this.

The last photo shows these two screw back in place and I am now psyching myself up for the big challenge ahead of installing these siz sets of hardware.


David

[Chris Suslowicz]

Originally Posted by David Dunlop

A number of interesting questions have arisen since its arrival, however.

I know production of this item did not start in Canada until sometime in 1941 and it was probably a direct copy of the British version. I have only ever seen photos of Canadian ones made by RCA Canada Limited and either bearing no date, or any of 1942 to 1944. This one is dated 1944, which ties in nicely with my 52-Set, but it was manufactured by Rogers Majestic Limited, which I believe was based in Montreal. It shows a Product Code of “R M SA 3897” and a Serial Number “C253”.

Is that SA (Sierra Alfa) or 5A (Five Alfa)?

5A is the Air Ministry stores code for "Electrical, Ground Lighting".

Second puzzle is this switchboard is identified as:

SW/BD CHARGING NO5C MK I

I never knew a Mk I ever existed until now and am now wondering what exactly changed in the design to warrant the Mk I status?
David

"Mk 1" is very rarely seen, because it's the original version of something. Later versions would be identified as Mk.2, Mk.3, etc. and there's the additional "*" marking indicating that an official modification has been applied, (as opposed to major changes or a redesign) e.g. Telephone Sets D Mark V* (or 5*), the * indicating the removal of the headband earpiece (and shorting of the "Phones" terminals) because they had switched to magneto signalling and the operator didn't need to wear a headset to hear the buzzer call.

I wonder if the "Mk 1" is a late-WW2 production of the original design, and that's why it has a plywood back cover and the extra terminals - they used the original drawings and not a later simplified (to ease production and cut costs by removing unnecessary features) version.

If I can fight my way into the shed I'll see what markings are on mine.

(I think that one has been repurposed as a switchboard for a workshop or caravan: all the charging terminals have been disconnected or removed, and the only terminals still connected are "Battery 2" "12V Output" and "Internal Lighting", the last being controlled by the switch at top right. Presumably the battery was removed for charging and there is only one battery?)

Whoops! (From a restoration thread in the HMVF forums...)

ZB/CAN/BR 0183

Sorry to be the bearer of bad news.

Chris.

[David Dunlop]

Not bad news at all, Chris. Surviving documentation on this product is so slim today, every bit of information is useful.

I rechecked the front panel ID on this Switchboard and can confirm the Product Code is Definitely R M Sierra Alpha 3897.

That rear view shot of the wiring will be very helpful. I have a friend in Steinbach taking photos of his as well for me to reference. First glance comparison to the wiring remaining in mine suggests what is still there has been significantly relocated. I will have to test what is still there to see if it makes any sense at all. I see at least one red lead going to a negative terminal so I will need to tread carefully. At this point, I cannot see a drastic rework of the wiring simply to add in two new sets of terminals. What was real may be fully bodged at this point.

My goal, pending discovery of MK I documentation, will be to simply mirror wiring of a basic 5C Switchboard into this one and leave the two sets of additional terminals on the Mk I empty until how they were originally integrated can be confirmed. Need to find two extra terminals for that detail in any event, but it should be doable.


David

[David Dunlop]

It seems that productive work on the 52-Set is going to be hung up for a bit. I have found components on several fronts of the project that require replacement and need to be ordered. However, the ongoing issues with the Canada Post system have effectively shut down that service globally and I already have some items trapped in that system for several weeks.

So, back to basic research.

While working on the Switchboard, Charging No. 5C Mk I, I ended up going to a section of the F 526 Identification List for the 52-Set I had never closely looked at before now. This was the few pages for the Switchboard and I discovered these pages were part of an Issue 3 for the F 526 that was published 02 June 1953. This revealed several interesting facts about Canadian Switchboards, Charging.

First off, I had always seen references to the fact the four switches on the British Switchboards were larger than the ones used in Canadian Production and used pressed steel switch covers, whereas the smaller, Canadian switches used Bakelite covers. Page 151 of Issue 3 of F 526 lists both black phenolic (Bakelite) covers and pressed steel as being available in the Supply System for the Canadian made Switchboards.

The second tidbit of new information was the original manufacturer of both the switch covers, and the complete switches, was identified by the abbreviation “AH&H”, along with their own part numbers for this equipment. It took a little extra digging but “AH&H” turns out to be the Arrow-Hart & Hegeman Electrical Company that was formed in 1927 in Hartford, Connecticut by the merger of Arrow Electric Co. and the Hart & Hegeman Manufacturing Company. At some point AH&H was absorbed by Cooper Industries, who in turn are now part of a global complex called EATON.

So although the Canadian switches are smaller than the British ones, it is quite possible to run across a Canadian made board with either Bakelite, or pressed steel, covers. Either will be correct.


David

[David Dunlop]

I discovered this morning that Lee Valley Tools had opened a shop in Northwest Winnipeg and they happened to carry 10-packs of brass, #6 1-1/4 inch, countersunk, slot head wood screws, so off I went and purchased a pack, all in with taxes for $4.03 Cdn.

That just left blending them in with the factory originals which were black adonized finish. As it turned out, I had a can of satin black rust proof paint on hand and a quick light coat of this dried as an excellent match to the originals.

In the attached photo, the two new screws are located at the top, second from the right and the extreme right at the bottom.



David

[David Dunlop]

I was reviewing my last post this morning and realized I had missed documenting a step in cleaning up the wood parts on the Switchboard.

After letting the initial soak of Lemon Oil soak into the wood and the volatile solvents evaporate away, I gave each part another soak of the oil and a light rubbing with 0000 Grade Steel Wool followed. This is the finest grade of steel wool available and it works a lot better than any sand paper product for smoothing wood finishes. My Dad and Grandfather used it and back in the early 1970's, an elderly Gunsmith, who used to own the Gun Shop in the old Hudson's Bay Company Store in downtown Winnipeg recommended the same product to me for cleaning up the wooden furniture on my collection of Lee Enfields. Works great on CMP Steering Wheels as well, if you are inclined to go that route.

The big player for this product here in Canada is still Bull Dog, who developed it in the 1930's in Thamesville, Ontario.


David

[David Dunlop]

I finished doing all the Resistance Tests for the Supply as whole and the Vibrator Supply, and have also written up specification sheets for all the resistors and capacitors in the unit. And some things do need looking at.

Starting with the Vibrater Supply, there was an interesting surprise when I looked under it shown in the first photo. Notice the long, grey, 10 Ohm resistor near the bottom of the image. This is not a factory original part and does not show up in any way, shape or form in the manuals. I initially thought it was a bog job but as I thought about it and made inquiries, the Modifications List for the 52-Set surfaced in discussions and it turns out this addition was part of Modification No. 4 covering required changes for operation of the 52-Set in the Arctic.

Turns out that in very cold weather, the 0Z4 and 0Z4A valves will just stop working. The fix was to switch to a 6X5GT valve, however, the filament voltage in it is only 6.3 Volts DC. This 10 Ohm, 10-12 Watt Wire Wound resister is connected from Pin 2 of the 0Z4 Octal Socket to ground. Pin 2 it not used for the 0Z4/0Z4A, but is the Heater connection for the 6X5GT. The resistor reduces the voltage from 12 to 6 Volts so the 6X5GT will run quite happily in extreme cold.

This mod was done to my 52-Set 12 June 1966 so it must have been going up north somewhere for a while. At that point in time CFS Alert and CFS Inuvik were the only two permanent arctic posts for the Canadian Military. Alert was RCAF and Inuvik was RCN. However, 1966 was also the start of the Canadian Governments experiment with unification of the three armed forces, so I have no idea what equipment might have been in those two stations at that time and thereafter for a while.

The second photo shows the location of the two resistors I need to get at to test. The lower one with the orange band is reasonable accessible but its twin is hidden under base plate of the large coil roughly centre in the photo. Fun times ahead me thinks.


David