Wireless Set No. 52 Canadian - Project

[Bruce Parker (RIP)]

There must be an easier way. The factory would have been pumping these out by the hundreds and wouldn't have fought as you are fighting. What was their secret? Any chance they were screened on?

Originally Posted by David Dunlop

I have completed a round of stencil tests with the brushes I recently purchased. I did not try the 3/4-inch brush as it was far too large for the size of stencil I am using.

The first attempt was the letter 'N' lower centre in the photo with the 1/2-inch brush. Way too much bleed under the stencil on its own so I stopped with the one letter. the next attempt was the test block to the right side with the 3/8-inch brush and the plain stencil. Cleaner, but still way too much paint bleed under the stencil. Both of these tests were done with multiple thin coats build up with the brush.

The last test was the block to the left. For this, I secured the stencil to the test folder with a coat of Rubber cement, pressed the stencil down with a pencil eraser to ensure the stencil was as flat as possible and I let the rubber cement dry for 20 minutes at room temperature. I then rubbed the excess cement off the top of the stencil with my finger and used a round toothpick to clean up any excess cement inside each stencil segment. Then out came the 3/8-inch stencil brush again and multiple coats were build up until the majority of the folder colour vanished.

A very slight bit of paint wicking took place, but overall, I am very pleased with this result and kit will be the process I use with the tool box stencil.

David

[David Dunlop]

Hello Bruce.

When I was in Junior High School, the Father of one of my friends was an Illustrator who owned a sign shop. He had a lot of silk screen equipment in their basement, and I wish I had paid closer attention to it all at the time.

I do remember the screens were a two part item consisting of the thin fabric screen and a mask bonded to one side somehow. You cut the design through the mask and peeled away the bits you wanted the paint to pass through. The huge advantage of this printing technique is the design and any characters therein can be solid and continuous. By comparison, a stencil requires webs in the characters to hold them together. It would absolutely be possible to cut a silk screen mask that looked exactly like a stencil, but why?

Screening was definitely used with wireless equipment during the war. You can see it on any 19-Set Spare Parts Box, or Spare Valve Box, and if it is minty enough, you can often see the fabric shadow in the white paint under a low angle light.

Looking on the web today, there are a few commercial, line production stencilling machines available, but most seem geared to working with electronic circuit boards and other small, thin items of that nature. It is entirely possible these modern, compact machines evolved from much larger equipment from decades ago. We may never know.

Regarding the various boxes/cases for the 52-Set, I have photos of two different tool boxes with original markings, one in Canada and the other in England. The stencil markings on both are spot on identical in both form and location on the two boxes. I also have on hand, two Spare Parts Boxes and again, the stencil marking shadows are spot on identical in form and location.

In the pre-computer era, Sign Painters and Illustrators, were highly skilled positions and there was probably a lot of cross reference to other closely related skills like screening, stencil making and even engraving…all hand done. These physical skills are largely lost today. The station on the line for stencilling these boxes/cases was probably occupied by a lot more than just one person to keep production numbers up as you have noted. It would not surprise me at all if each work table was set up with jig options to hold the various cases/boxes in a specific spot, and perhaps even some form of mechanical arm which could swing the stencil down to the same spot for each type of case/box being worked on.

The viscosity of the paint is also critical. Too thin and it will wick under the stencils in a heartbeat. Too thick and it becomes hard to apply and you risk it drying out. Just right, and a skilled worker, and away you go!

Sorry for the length of this reply, Bruce. It amazes me what the older generations were able to accomplish with pure mind power and great hand/eye coordination and as much as I would love to know how they accomplished things like applying these markings, an answer may never be found. In the meantime, I shall muddle along and try and honour their collective skills as best I can. That probably means I end up drinking more than any of these workers ever did, but that is not a complaint…

David

[Bob Carriere]

.....works good BUT will leave permanent mark on flat OD paint like truck doors. A stencil cut on 15mil acetate held in place with magnetic strips works well with very thick stencil paint and foam dabber.

Flat OD paint will mark very easily and cannot be repaired short of repainting the whole door skin... trying to re-spray patch always mess things up and stencil paint has to be re sanded to bare primer.

Cheers

[David Dunlop]

Bob raised a couple of interesting points last week regarding the use of stencils and to be on the safe side, I decided to double check both factors before proceeding further with work on the tool box.

The first potential problem was the use of rubber cement on flat paint, or even semi flat paints.

Years ago I restored a pair of M38 CDN’s and painted them both the original semigloss factory green. I was lucky at the time a company called Rondex here in Winnipeg, still had the original paint sample catalogs for Dulux paints and it covered all the Canadian Military Vehicle colours from the factory new M-Series back to 1944-45. When it came time to apply the CFR Numbers I used stencils mounted to the vehicle with rubber cement with no problem at all, but the paint in question was an enamel semi-gloss. Today, the term ‘semi-gloss’ seems to have disappeared from paint terminology, being replaced with names like ‘Eggshell’ or ‘Satin’, and most paints today are latex or other water-based variations.

So my first test last week was to coat a small piece of oil board with rubber cement and stick it to the bottom of the tool box, wait five minutes, peel it off, let the cement dry completely and rub it off to see what happens. As per the first three photos, the solvents for the rubber cement did not alter the finish on the satin latex paint at all. Good to know.

The second point Bob mentioned was the use of those small foam paint brushes to apply the stencil paint. Debbie happened to have quite a selection of these in her crafting supplies so I borrowed one of the small, black rectangular ones with the chisel tip to test it out.

The last photo shows the results of this test in the lower left corner after the stencil had been glued down with rubber cement and the excess cement cleaned off prior to painting. Directly above that test is the sample done with the 3/8-inch stencil brush on the same glued down oil board and off to the right the same brush on an unsecured oil board. After looking at the results for a bit, my quality ranking would be the top left result with the small stencil brush is best, followed pretty closely by the foam brush below it and a distant last place is the unsecured stencil and small brush to the right side.

I think the problem with the foam brush test is more a factor of the small size of the stencil cutouts, rather than the foam brush. With the narrow openings of the characters, too much of the foam is on top of the stencil and the foam has difficulty getting in close to the edges. As a result, the sections of some of the characters have varying widths to them. With the small stencil brush, some of the bristles clearly hit the face of the stencil, but not enough that they still flex and allow the other bristles to reach down inside the cut-outs and fill it more evenly with paint.

I think with larger sized stencils, a foam brush could easily hold its own with a bristle brush for stencil work.

So with that out of the way, and thanks again Bob for raising these points, the next step will be to apply the required stencil to the tool box.


David

[David Dunlop]

I applied the stencil to the tool box this morning and I personally think it is the worst bit of restoration work I have ever done!

The tool box was on its back on a thick towel on the bench and I applied a good amount of rubber cement to the stencil before correctly aligning it down on the front of the box. I then placed a heavy steel plate weight over the top and let it sit for half an hour at room temperature.

After removing the weight and carefully rubbing away all the rubber cement that had to go, to get a clean working surface, I started the slow stencil brushing process with the 3/8-inch stencil brush. I even held down suspected problem areas on a few characters with the head of a 4-inch common nail to be on the safe side and made sure the paint was built up of several thin layers, rather than one or two heavier coats.

After half an hour for the paint on the stencil to dry to the touch I carefully removed the stencil and cleaned it up. An hour pater I carefully rubbed off any dried excess rubber cement. Of 51 characters on the stencil, 20 require touch up work, and of those, six need it badly. I will worry about that next weekend to let the white stencil paint fully cure.

On the bright side, I have an entire winter looming ahead with lots of free indoor time available to tidy this up. I still have a package of large pink rubber pencil erasers left over from restoring the damaged original decals on the 52-Set Sender panel. They should work just as well for this task, along with the same set of ultra fine tip paint brushes.

I also took some time this morning to have a much closer look at the original stencil on my 4-Section Aerial Reel. There is not a trace of a brush mark anywhere on any of the letters, or any form of screening for that matter. What I did see, however, was an ever so slight ‘ghosting’ of paint along the bottom edges of the lower two lines of the stencil.

Bruce raised a good point the other day regarding the Stencil Station on the Production Line. They would be getting a lot of items through that station daily and it would be a bottleneck in no time working stencils by hand with any sized stencil brush, regardless of staff compliment. Canadian Marconi could certainly have used air guns at this station, but that seems like overkill. Air guns in paint work are at their best for large volumes of paint over large areas quickly and pack a fair bit of air pressure behind them. They would be wasting a lot of paint using them for stencils. Stencils are much more detail oriented. I don’t know why it never crossed my mind earlier, but perhaps this station on the line was using Air Brushes. Air brushing was a very common function in the photographic sector prior to the computer age and that spun into all sorts of publication work. Air brushes were also common for a lot of detailing in paint shops in many sectors. The Cabinetry Division at CMC probably had them on hand for fancy detail work and they operate well at pressures far lower than what is needed for a common air gun. With an air brush at a stencil station, an operator could easily master holding the stencil in a jig by hand and work an air brush at the right distance and correct paint load to get little or no under spray behind the stencils, and with that equipment you would have much greater throughput for the line.

Maybe I will dust off my Air Brush and try it out when I get to working on the Spare Parts Boxes and see how it works. Assuming senility does not take hold in the meantime.


David

[Bob Carriere]

Hi David

I would have concerns using any kind of air brush as it might lift the stencil ever so much.....

The stencils I have seen that were used repeatedly were made of cut out brass sheets and very rigid....... and they used a roller ( in Black) and the dabbing brush was a well worn caked short hair thing that had turned into a felt like glob of semi dried paint....... worked well on wooden crates going up North.

Crates had the lettering over painted white and reused.......

This was done in a wharehouse and in some cases the trucks were idling at the dock to be loaded.....

Your tool box is really well done........ not sure they would have been all done so neatly in a shipping department........ reminds me of all the highly visible spot welds done on CMP bodies..... if it was solid it got shipped.

Love to follow all your hard work!!!!

Cheers

[Jordan Baker]

See the following link for a few period photos of how markings could be applied.

http://www.questmasters.us/Restoration_Supplies.html

The 4 sections aerials reel looks to have been sprayed.

There is also what’s called rocker mount stamps. Once the stamp is made, the application goes very fast.

[Alex van de Wetering]

David,

Nicely done and thanks for sharing your experiences here!

I guess if you have trouble with the cardboard lifting from the surface due to the moisture from the paint or air flow from the paint gun...you could try thin plastic sheet or sticker material in stead. I presume the stencil should not have any trouble cutting this.

Originally Posted by Bob Carriere

Hi David
The stencils I have seen that were used repeatedly were made of cut out brass sheets and very rigid.......

I have a set of those....it has individual letters in brass with a small ridge along the edges, that allows you to, sort of, link multiple letters into words. Presemably mine are post-war Dutch or German army.


The website that Jordan posted gives some nice pictures of the different applying methods used in period.....and also shows why lettering on original items is not always properly centred, straight ....and sometimes with paint smudges. Something we try to avoid as restorers!
What I do always find annoying with these stencil suppliers is that they seem to spend no energy at all at getting the font right! This website even shows a comparison of first aid boxes and it clearly shows the text is the same, but the font is wrong.

If you are using pre-made original stencils, or a stencil machine like David is using, you'll find that the width of gaps in the material is usually equal, I mean the font is specifically designed for stencilling, avoiding narrow grooves where paint can't properly run through. Some of these custom stencil suppliers however use computer fonts which are designed for book print or even web-use, designed along different guidelines, for instance to make them easier to read. As most of these suppliers will sell you stencils cut in sticker material, which seems to work very good for applying markings on vehicles by the way......why not use the proper font in stead? The cutting plotter wouldn't mind!

[Bruce MacMillan]

I have a 1/2" set of brass stencils which work well. They don't tear or warp.
They are available in other sizes and I've seen some on the auction place.
I used an airbrush and stencils cleaned up with spirits (using enamel).

[David Dunlop]

After starting at the tool box for a few days, I decided to focus on the half dozen or so really bad characters for some careful touch up work and leave the rest as they ended up.

With that all done, I now feel a lot better about the over all look of this stencil. I think the biggest improvement is in the second line “ZA Number” where all the zeros are finally consistent in appearance. The same for the letters D, W, S and B.

As far as markings on this box go now, the only thing left to sort out is the size of the C-Broad Arrow Stamp on the right side of the lid from a surviving example in a photograph of a 52-Set wooden case and the one on my Aerial Reel, the colour of choice seems to have been black. The reel shows a 1/4-inch stamp but the wooden case could either be 1/4-inch or 1/2-inch. Time will tell I guess.

Thanks for all the posts on wartime military markings. Clearly quite a variety of methods were used. It boggles the mind really!


David

[David Dunlop]

General Motors of Canada was struggling to get the newly developed C15TA Armoured Truck delivered to the Canadian Army about the same time as Canadian Marconi was working on initial deliveries of the Wireless Set No. 52. There was no hope of getting an Installation Kit developed for the 52-Set into the C15TA, which was replacing the White Scout Car FFW, so the Canadian Army developed a set of Field Installation Instructions for fitting pairs of the 52-Set and the 19-Set HP into the C15TA from metal stocks available in workshops overseas. These instructions were developed early on in the 52-Set production run and it was surprising to notice that the Lift the Dot fasteners used across the top of the Curtains, Waterproof on the 52-Set were nickel plated, not Matt Black as I suspected they would be.

The first photo today shows these nickel plated fasteners clearly on the right half of the curtain, the one dead centre below the Coil, Aerial Tuning in particular. Somewhere, I have another photo showing quite a bit of reflection off all five of these fasteners but cannot find it at the moment. The price I pay for having several thousand photos scattered across three computers, two large memory sticks, a digital camera and two camera memory cards. Consolidation is ongoing but nowhere near complete.

In any event, the nickel plated hardware did not make much sense, and I wondered if the name change in production from Curtain, Waterproof to Covers, Waterproof might have been done when CMC realized the mistake in hardware and switched production to Matt black. I got in touch with known 52-Set owners in Canada to see if they had these canvas items and asked for photos of the front markings and hardware to see what might turn up. Only three survivors so far, all the early marked ‘Curtain’ issue. Two down in Southern Ontario both have nickel plated fasteners. What was really interesting, however, was a third original curtain showed up in Alberta with Matt Black fasteners. So it may turn out that if any Covers have survived, they should all be equipped with Matt black fasteners.

I will let you know what turns up.



David

[David Dunlop]

And the Matt black version.

David

[David Dunlop]

It could prove to be an interesting four days coming up.

I was giving the 52-Set a routine workup two nights ago, running the receiver for about 20 minutes with the Sender Heaters active. Then switched on the Netting to run the 300 Volt Dyno for 3 or four minutes. I then switch Netting off and switch the set from Reeceive to Send. This turns the 300 Volt Dyno back on with the 1200 Volt Dyno. I normally let this pairing run a couple of minutes and power fully off. Done this several times a week for nearly three months.

This time...not 5 seconds from switching to Send, I could smell burnt varnish/wax coming from the Sender Blower Door so switched off immediately. So this weekend the Sender comes out of the Carriers No. 4 again for a close inspection.

David

[David Dunlop]

With an even mix of curiosity and trepidation, I decided on a simple test of the 52-Set this evening.

I warmed up the Receiver and Sender Heater circuits for nine minutes, took a deep breath and switched on the Netting circuit for the Sender. This activates only the MG1A (300 Volt Dynamotor).

A constant sniffing of the air at the Sender Blower Door showed no sign of a smoke smell and a nice subtle ozone smell from the Supply Unit Blower was evident. After two minutes running, all was still well.

This at least tells me the problem is somewhere in the 1200 Volt circuits of the Sender.

Every little bit of information helps.

David

[David Dunlop]

I pulled the Sender out of the Carriers No. 4 this afternoon and got it on the bench. 20 minutes later, after a careful visual examination, I could see, or smell, no trace anywhere of recent overheating.

Next step will be removal of all the valves and a complete redo of the three resistance tests for the Sender using the same VTVM I did the original tests with earlier this year. This was something I had planned to do anyway after carefully cycling the 300 and 1200 Volt power feeds from the Supply Unit though the Sender over a period of time.

There were a cluster of unusually high resistance readings in the first tests I am curious to see any possible changes in. Also, I may now find an earlier, normal resistance value that has suddenly gone south, which might point to the potential new problem. It will take a few days to complete, since access to a few of the test points required temporary unfastening and moving of some components.

David

[David Dunlop]

A rather nice parcel arrived in the mail today from Alberta.

This particular Curtain, Waterproof is a replica, made over 20 years ago by an Edmonton tentmaker, copied from a borrowed, surviving original at that time. They could not get a perfect match to the original colour of green canvas from available stocks and the weight is slightly lighter than the original as well. What I liked, however, is they matched to the nickel plated hardware on the original.

I do not know where the original Curtain, Waterproof came from, or ever ended up, but at least we know it was still surviving a while ago.

While installing it to warm up and hang, I discovered the rightmost Lift The Dot post riveted to the top of my Carriers No. 4 has been bend slightly to the right. Surprisingly, the post itself seems to be OK. The bend had taken place in the upper sheet steel of the Carriers No. 4. With a little TLC down the road, I might be able to dolly the sheet metal back level. Added to the ‘To Do’ List in any event.


David

[David Dunlop]

Thought I had better show a photo of the Curtain, Waterproof rolled up in the stored position on top of the Carriers No. 4, while I have the Sender out for testing. Notice how it forms a smooth, cylindrical tube when fastened down.

Anyone with an original Curtain, Waterproof can probably confirm this, but the smooth look of this curtain in the stowed position is very likely due to the fact it is a replica made from a bolt of canvas that has not been treated with the usual paraffin and wax solution to actually waterproof it. You will notice in the first photo of my previous post, when in the deployed position, the weight of the steel bar in the bottom edge also holds the canvas in a smooth tight sheet.

I noticed these effects last evening and checked the waterproof covers on my Mk II 19-Set and Variometer and my Mk III mounted on the Carriers No. 23. All three of these canvas items are very stiff, you can still smell the waterproofing when they get warm and they only ever really 'relax' when they get warm.

I don't think I will ever bother to apply any traditional waterproofing to this replica, but I might give it a spray of silica boot waterproofing, just to validate the name of the curtain, if nothing else.


David

[David Dunlop]

The 3rd set of resistance tests for the Sender were completed yesterday and overall, the results were very consistent with the two sets of tests run last Spring.

Of none electrical note, the rust on my VTVM Testing Procedures is now shedding in huge chunks. Most of the red flag readings I took earlier that were ‘Infinity’ in nature produced excessively high, but real values this time around. This was primarily due to me focusing on taking advantage of the different testing ranges on the meter to see if and where I might actually get a useful reading. It is amazing what one can forget when being an infrequent user of helpful equipment.

The majority of the good readings were either identical to the earlier ones, or +/- very, very close, so that was nice to see as well. The red flags are all clustered in the same circuits as earlier and the other big plus was nothing new showed up that might have been related to the overheating event that happened a few weeks back, so I have inflicted no new damage…so far.

The dark side of all this, however, is my next step in the process. I now have to go back to the Sender Circuit Diagram and methodically trace out each red flag circuit to identify all the related components. There are likely a few resistors that have dropped off in value, but most of the problems are probably going to be with the PIO Capacitors that have transformed themselves into resistors. The problem now though is the 52-Set Circuit Diagram for the Sender is very compact for easy reading/tracing. One sooner or later has to resort to using a magnifying glass, or lamp, which narrows down your field of view, compounding the problem. A whole different experience from working with 19-Set diagrams.

The challenges don’t stop there either. Once I have identified all the components that need further investigation, I have to find them on the chassis and test each. The ones tied to valve socket terminals are the easy ones. It is the remote ones tied to a terminal panel, tucked behind another component, six inches away that create the nightmares.

Good thing it is a long Winter in these parts.


David

[David Dunlop]

As expected, and not withstanding current seasonal activities, the analytical work involved in tracking down problems identified in testing electronics is moving painfully slow for me. The price I pay, I suppose for not doing enough of it over the last few decades. In any event, progress is actually being made.

The initial point of interest was that across all three resistance tests, the problem results were nearly all of excessively high values, and most were directly related to tests in which the Mode of Operation Switch on the Sender was set to the R.T. Mode. A number of these results, of course, showed up with Pin to Ground readings for the 813, which was a little scary initially. Then I finally realized the Speech Circuit would be the common factor across all these problem results.

The Speech Amplifier in the Sender is V1J, an ARP-3 Valve, and in close relation to it is V5D, the Modulator, the position of which is taken up by a 6V6G Valve.

In the tests result, V5D, showed no real problems and it shares some of the circuit components of V1J. V1J, on the other hand showed good results until tests involved it be active in the RT Mode and then results went off the charts. So V1J now has my undivided attention.

The two problem circuits for V1J include 3 capacitors, one of which is electrolytic, and 5 resistors. One of those resistors shows normal values off RT Mode and three of the others are shared when required by V5D, so may be OK. The stage of my work now, is finding where all eight of these components are located on the actual chassis and testing each individually. An interesting challenge in its own right.

In the two photos today, the first shows the V1J socket at the bottom, partially hidden by the T2A transformer (easily removable), with the V5D socket directly above it. I suspect all of the components needing examination will be either tied directly to the pins of these two sockets or hiding somewhere along the board in the second photo which is fastened to the lower rear edge of the Sender chassis with three screws.

Hard to do, I know, but it would have been nice if the capacitors could have been mounted on the boards with the useful specs data showing. I have found more than enough in 19-Sets and other equipment, including this 52-Set, where the only readable information is the capacitor makers name or “MADE IN CANADA” and the side with the critical specs is securely fixed against the circuit board.

The journey continues.


David

[Chris Suslowicz]

Originally Posted by David Dunlop

As expected, and not withstanding current seasonal activities, the analytical work involved in tracking down problems identified in testing electronics is moving painfully slow for me. The price I pay, I suppose for not doing enough of it over the last few decades. In any event, progress is actually being made.

The initial point of interest was that across all three resistance tests, the problem results were nearly all of excessively high values, and most were directly related to tests in which the Mode of Operation Switch on the Sender was set to the R.T. Mode. A number of these results, of course, showed up with Pin to Ground readings for the 813, which was a little scary initially. Then I finally realized the Speech Circuit would be the common factor across all these problem results.

(Snipped a bit.)

The two problem circuits for V1J include 3 capacitors, one of which is electrolytic, and 5 resistors. One of those resistors shows normal values off RT Mode and three of the others are shared when required by V5D, so may be OK. The stage of my work now, is finding where all eight of these components are located on the actual chassis and testing each individually. An interesting challenge in its own right.

High values in the resistance tests will not be caused by faulty capacitors - they should have infinite resistance (waxed paper/paper in oil/ceramic/silver mica types) or a low resistance that increases rapidly as they charge up (electrolytics). Capacitor failures are usually low resistance (electrolytics where the oxide dielectric layer has dissolved), moisture entry (waxed paper), or short circuits (silver mica), or else open circuit failures. High resistances are more likely due to resistor ageing or dirt/corrosion on switch and relay contacts - so it's worth using switch cleaner on those if the results of the testing are "off" in one position.

Capacitors should be checked for low resistances (may need to lift the wire at one end so you're only testing the capacitor and not any associated resistors), and reformed (electrolytic types) or replaced (all types) if leaky.

Hard to do, I know, but it would have been nice if the capacitors could have been mounted on the boards with the useful specs data showing. I have found more than enough in 19-Sets and other equipment, including this 52-Set, where the only readable information is the capacitor makers name or “MADE IN CANADA” and the side with the critical specs is securely fixed against the circuit board.

The "PC" number is visible on a lot of them though, so if you've got the actual parts list that will tell you the value and rating. PC = Procurement Catalog(ue), and it's common to all equipment so you can use the numbers from the WS19 if they're in that manual.

It might be worth making a list of PC numbers and the specification as you work through the restoration - looking up visible numbers is a lot easier than dismantling the set to get at the hidden side (though you may need to do that anyway if it's faulty and has to be replaced).

Best regards,
Chris.

[Mike K]

This guy has many excellent tutorials on repairing old tube equipment

https://www.youtube.com/watch?v=lLQThhf3Brc

[Chris Suslowicz]

Originally Posted by Chris Suslowicz

(Snipped a lot.)

The "PC" number is visible on a lot of them though, so if you've got the actual parts list that will tell you the value and rating. PC = Procurement Catalog(ue), and it's common to all equipment so you can use the numbers from the WS19 if they're in that manual.

It might be worth making a list of PC numbers and the specification as you work through the restoration - looking up visible numbers is a lot easier than dismantling the set to get at the hidden side (though you may need to do that anyway if it's faulty and has to be replaced).

Having looked at the 1945 Identification List (does not contain PC numbers) and the WS52 User Handbook. (Which only contains CMC part numbers!) I don't think my suggestion was very helpful - though the User Handbook does list what the various capacitors relate to, which may be some help.

Chris.

[David Dunlop]

Hi Chris.

Actually, you did jog me in the direction of checking the 19-set documentation for possible cross references, which I had not thought of to this point in time. So Thanks on that!

I then went back into the 52-Set Operators Manual to see how useful the data there might be and discovered of 51 different capacitors in the 52-Set, only 5 were actually identified by PC Number. As you noted, all the others had Canadian Marconi Part Numbers. Be interesting to see if the CMC Numbers were actually stamped onto the caps used in the assembly process. I shall find out shortly I suspect.

On the bright side, however, I did stop this time and read the prefix notes Marconi included at the front of the Parts Index at the back of the Operators Manual and noticed they had included a reference to the fact quite a few of the capacitors used in the 52-Set were also used in the WS No. 9 and WS No. 19 and those parts supplies can be drawn on to effect repairs to the 52-Set, if necessary.

I will keep you posted with what I find hiding on the chassis and this might even allow me to play a bit more with some photo software, of which I have explored very little over the years.

Cheers for now,

David

[David Dunlop]

Good Evening Mike, and thanks for the interesting link.

I actually purchased a new LCR Meter similar to the one shown in that video a few years ago, primarily for the ease of testing capacitors that are still in circuit. The conventional method wherein one needs to disconnect one end of a cap to test it can be a real PITA if the cap is difficult to access to start with and then you find it is working just fine and have to reinstall it. Been there, done that and hate the T-Shirt.

The two pieces of ‘older kit’ he had were interesting for their in situ testing capability of capacitors. Way back in 1946, the Solar Manufacturing Company produced their Model CF Capacitor Exam-eter. Each meter came with its own calibrated manual and a set of test leads, one of which was a matched lead similar in approach to the one in the video somebody had bodged. My leads were missing, but there was enough data in the manual, along with some very astute notes made by the Radio Engineer who originally owned my meter, that I was able to replicate a new pair of leads.

This meter can do a staggering number of tests on capacitors, as well as resistance testing, AC and DC Voltage checks and a few others. I have done some resistance testing with it out of curiosity and it gives results very close to what I get with my vintage RCA and Simpson VTVMs.

I have somewhat limited mains supply at my work bench and two things came to the forefront in purchasing the new LCR Meter. It is battery driven, so no plug in requirements and, it will eventually give me a means of comparison for capacitor test results from the vintage Solar meter.

If there is a dark side to all this, I must remember to always be careful with wayward voltages when using a modern digital test meter on vintage valve driven electronics.


David

[David Dunlop]

Lately, in the time spent stepping away from the resistance analysis of the Sender, in order to clear my head, I have been thinking about the reasoning behind the Canadian Marconi Company changing the name of the piece of canvas they designed to provide some degree of moisture protection to the front of the 52-Set.

When you first look at it, everything makes sense. It rolls up and down in front of the Set, just like a ‘curtain’ in a window. It is waterproof, but absolutely not weatherproof. If the operator was caught outdoors in the rain working a 52-Set, I would not want to be that operator. In the rain, nothing about a 52-Set would be ‘covered’ with this simple piece of canvas.

Why Marconi chose a light olive green canvas for their curtain, may simply have been a factor of product availability at the time they needed to get the curtain into production. Khaki Tan may just not have been available. Nothing about any of this appears to be sloppy work on the part of CMC. They clearly knew it would be unwise to operate a 52-Set exposed in wet weather. If it was not going to be installed in a fixed building, or an enclosed vehicle, CMC went to the trouble of ensuring a Wireless Tent Kit was available to operate the 52-Set. Marconi had covered all the bases.

Photo evidence suggests the first curtains that used nickel plated hardware was a bad idea that Marconi identified and fixed, switching to matt black hardware in production as soon as possible. To date, no 52-Set components have turned up bearing 1945 dated data plates, so if seems logical production of the 52-Set ended a some point late in 1944. This would have included full sets, kits and a appropriate amount of spare parts. However, the February 1945 Master Parts List identifies this canvas item as “COVERS, Waterproof No. C2” but advises items may be found identified as ‘curtains’ and this is to be ignored. Identical information is found in the July 1948 revision of the List. It seems likely, therefore, the identification of ‘COVERS, Waterproof No. C2’ is a pure piece of supply system paperwork, simply for standardization purposes. It is highly likely, items were never manufactured bearing this identification.

I took a look in my 19-Set Parts Lists and found the following five covers:

COVERS, Waterproof No. 1 ZA 2952 for Carriers No. 21
COVERS, Waterproof No. C1 ZA/CAN 1076 in Universal Carrier
COVERS, Waterproof No. 5 ZA 10317 for Carriers No. 23
COVERS, Waterproof No. 16 ZA 10411 for Variometer
COVERS, Waterproof ZA/CAN 1362 for 19-Set Cdn in Carrier Universal


So in spite of the fact the 52-Set ‘CURTAIN, Waterproof’ is indeed a ‘curtain’ and does not cover the set at all, as any of the above noted items would, bureaucrats decided the name must change, not Canadian Marconi.

The three attached photos are of the following COVERS in my collection: No. 1, No. 5 and No. 16.


David

[Chris Suslowicz]

Originally Posted by David Dunlop

I took a look in my 19-Set Parts Lists and found the following five covers:

COVERS, Waterproof No. 1 ZA 2952 for Carriers No. 21
COVERS, Waterproof No. C1 ZA/CAN 1076 in Universal Carrier
COVERS, Waterproof No. 5 ZA 10317 for Carriers No. 23
COVERS, Waterproof No. 16 ZA 10411 for Variometer
COVERS, Waterproof ZA/CAN 1362 for 19-Set Cdn in Carrier Universal

The three attached photos are of the following COVERS in my collection: No. 1, No. 5 and No. 16.

David

I can add Cover, Waterproof, No.7 which is for Carrier No.25 with the top plate fitted (this carries the Variometer, Aerial Base, and Control Unit).

This has two exit holes for an aerial rod (with Grommet No.23 and a blanking grommet so that the aerial base can be in either position), large holes with water protection flaps on both ends and at the rear, to allow for cabling to other control units - they will pass a 12-pt connector, etc. It's a complicated bit of canvas. (The stitching is going on mine, and I need to get it repaired.)

Chris.

[Bruce MacMillan]

Here's some more info the the WS52 from the Canadiana site. Also lots of other wireless stuff.
https://heritage.canadiana.ca/view/o...eel_c5817/1341

[David Dunlop]

Thanks for posting that link, Bruce.

Looks like I will be able to do some more research reading this weekend.


David

[David Dunlop]

Earlier this evening, I finally found the last component I needed to investigate related to the abnormal test results I was getting for the V1J Speech Amp circuits in the Sender.

The component was resistor R49A, related to the V1J Plate Load and I had to remove the T2A Transformer, once again, from the rear skirt of the Sender chassis to reveal its location. I had suspected it was hiding back there at the very start of this quest, and had actually looked with a small, flexible mirror behind T2A, to no avail, so I went on to track down all the ‘easy’ stuff first. More on that later.

In any event, to save anyone else hunting for this resistor down the road, here is a photo of what it looks like and where it hides. It is rated at 100 KOhms, with a +/- 20% tolerance at 1/2-Watt. This one tests out at 126.4 KOhms, so is now on my “To Be Replaced” List.


David

[David Dunlop]

All of the required resistors have now been tested and I have just started looking into the capacitors. To complete that portion, I will need to remove the circuit board mounted on the rear chassis skirt, shown in the second photo in Post #949, and I will have to study that setup a bit first, before removing the three mounting screws holding it in place.

I also discovered that it is possible to carefully spin the cardboard sleeves on those four capacitors around their metal cores, so I was able to wipe all the dust and dirt off them all and expose the sides showing their PC-Numbers and Stats. In addition, as Chris had suggested, I was able to ID two of these capacitors by cross reference to the 19-Set Documentation. So now all four of them are identified

I will sort the resistor results shortly and post them


David