Wireless Set No. 52 Canadian - Project

[David Dunlop]

It is interesting how simple little things can bring a big project to a halt.

The valves from the Sender are all neatly packed away on a corner of my work bench and the Sender sits quietly covered up to one side, while I try and sort out finding replacement Carbon Composite Resistors that I can actually work with in the 52-Set restoration.

The problem is with the modern overall length of new resistors (lead, body, lead). Turns out wartime manufactured resistors of this type had an overall length of about 3.4-Inches. With the two main sizes of Tag Panels used in the 52-Set having tag spacings of 2.25-Inches and 2.50-Inches, this component length was ideal. What I have been finding in the modern market are most overall lengths coming in at 2.38-Inches, so you can quickly see the road block.

On the bright side, some international inquiries have resulted in leads trickling in (yes, there is a pun there) of a few suppliers about with Carbon Composite new made resistors with overall lengths close to 3.0-Inches. I may have to go to higher wattage ratings than the original resistors to get ones that will fit, but that will not affect performance at all. It is just all very time consuming.

And there is yet another wrinkle in the T-shirt. To replace all the resistors currently identified as needing it, two of the Tag Panels must be removed from the sides of the Sender chassis to better expose the tags for working on and these panels hold nearly 10 capacitors that need to be tested. I cannot reach the back terminals on any of them for testing at the moment and I know a few of them will be toast. Adding to the excitement, a few of the capacitors will have to be removed to expose resistors tucked behind them that need replacing. So a whole bunch of adventures are currently hurtling down the side roads towards the main highway and I still have not finished reading the road map!

There is an interesting curious side to all this, however.

Since I had carefully disassembled the spare Receiver I had on hand, I decided to check if any of the resistors I needed to replace in the Sender, might also have been used in the Receiver and test them for possible use. There were a few, but all were installed in locations where, if carefully removed, their leads would have been far too short for reuse in the Sender in any event. But something interesting in the way the Canadian Marconi Company arranged the parts lists in the Working Instructions Manual for the 52-Set unexpectedly popped up when you looked at long lists of the same component.

It is common practice for companies to list specific parts in ascending order of their electronic specifications. For example with resistors start with 1/4-Watt and within that group list from lowest Ohms value to highest. Then go to 1/2-Watt and repeat. And so on. Same process for capacitors. CMC took this organization one step further. They have a column in the parts lists that identifies which component the parts are used in and I discovered when looking at the larger lists of identical parts, CMC always listed the components in the following sequence of first to last:

R: Receiver
CC: Crystal Calibrator
S: Sender
SU: Supply Unit

So if you look at capacitors in the C3- series ( .1 uf, 500 Volts, 20%), there is a lot of them. C3A to C3Z are all found in the Receiver. C3AA to C3AF are found in the Sender and C3AG to C3AK are in the Supply Unit.

At the other end of the spectrum, C32A ( .01uf, 500 Volts, 20%) is in the Sender and C32B in the Supply Unit…end of list for item.

I do not know why CMC adopted this convention in the parts list found in the 52-Set Working Instructions, or even if they did it in other products as well, but at least I now am aware that any future components in the Sender I find with a Circuit Reference Number ending in ‘A’ will definitely not have a spare lurking in the Receiver or Crystal Calibrator.


David

[David Dunlop]

One of the nice things about a project this size is that there is always things you can accomplish when work stalls somewhere else.

That is the current case with the component replacement work I ws doing with the Sender. It is going to take a while to source all the required resistors and capacitors I need to hopefully solve the majority of issues around valves V1J and V5D and all the bits need to be replaced at the same time. So I have returned all the valves to the Sender and the Sender to the Carriers No. 4 until such time as I have all the needed resistors and capacitors on hand.

There is a trick to getting the three main components back into the Carriers No. 4 easily. If you do not keep the chassis you are putting back completely square to all side of the Carriers No. 4 as the sockets on the chassis engage the plugs at the back of the Carriers No. 4, they will bind up and it is a royal pain in the butt to get them apart. The Sender slid in so smoothly this time, I almost thought something had gone horribly wrong.

So the part of the project I moved over to was a little painting detail on the hammer that is part of the tool kit for the Wireless Set No. 52. The original hammer was a ‘BULLDOG’ product, from what I can make out on the decal in the first photo today. A pair of tool companies show up in researching this name, one in England and the other in the United States. A few old photos of corporate logos show up, but none so far of that elongated diamond decal in the illustration. The hammer I found for the tool kit is not made by Bulldog and the handle length is about one inch shorter than the original tool specifications, but on the plus side, the handle is the correct shape, clear varnished hickory and the head is the correct weight and style; the second attached photo. I had no idea there were so many different styles of ballpane hammer heads until this project arrived in my lap.

I may never find a good condition original hammer for this project, so decided to replicate the look of an original with what I have on hand. The most obvious feature is the black end on the handle, but the top end of that feature has a distinctive angle to it. Practice as I could, I was not able to get that good a look with any kind of tape rapped around the handle. You are trying to keep a straight line around an oval cross section that is narrower at the top than the bottom of the angle. After months of ruminating over this, I finally had my ‘Eureka Moment’. If the end of the handle was dipped into paint at the correct angle, to the correct point on the handle, mission accomplished. But how does one keep the handle perfectly steady? A few days of thinking about that …and then I realized, you fix the handle and move the paint can.

I did have a one quart can of gloss black enamel on hand that would work, so that was a start. The next step was to get reference points onto the front and back faces of the handle to pinpoint the two ends of the upper angled paint line. I was able to scale these two measurements off the illustration and proportion them, with some basic High School Math, to the shorter handle I was working with and transferred these two reference points to my handle; the third and fourth pictures.

So far, so good.


David

[David Dunlop]

The next step was sorting out fixing the hammer I had in a stable correct position to work on. My portable bench vise came in handy here. The first step was to fit a small strip of oil board over each jaw of the vise to avoid marking up the head of the hammer. I then fit the hammer into the vise just firmly enough I could still move it back and forth in the jaws. Also checked to ensure the handle was dead vertical to the floor.

I could then set the vise close enough to the edge of the bench the hammer sat freely out of the way. With the help of a spirit level, I was able to adjust the hammer handle until the two reference marks were dead horizontal. Photos 1 and 2 here.

With the paint mixed, off came the lid and a quick check confirmed the level of the paint was low enough that it would not spill out as the hammer handle displaced the paint when immersed in it. Since the paint was a liquid and seeks its own level, I really only needed to reach the top of the reference mark on the back of the handle to get it right, but I had to raise the paint can slowly enough to allow the meniscus to just come up the the required point and then lower the can back down.

There were a couple of points to consider now. Most important was the handle is at an angle now and all the excess paint is actually draining towards the front and bottom corner of the handle. That is OK for a short while as that means the excess paint is draining away evenly from the angled line you have just created, and you want that initially.

I held the paint can under the handle until the steady flow of paint ceased and the subsequent drops became infrequent and made sure a pile of rags was on the floor directly under the handle. At this point, the paint is still going to flow down the handle slowly, but you now want this to flow evenly around the entire handle so the thickness of the final paint layer is even around the entire handle. That means slowly moving the hammer handle back to a vertical position; the 3rd photo. At this point, I used paper towel to draw off excess paint from the very bottom of the handle, several times over the next hour, to reduce a ridge accumulation of paint around the bottom rim of the handle as much as possible.

24 hours later, the paint was dry and I was able to remove the hammer from the vise. I am quite pleased with the result in the last photo. A bit glossier than the varnished areas, but a little careful rubbing down after the paint has hard cured in a couple of weeks, will solve that problem.

If I ever do find an example of the original BULLDOG diamond decal to work with, I am also going to have to add a small black paint and metal stamped ‘R’ to the side of the handle to clearly ID it as a replica.It is what it is, not what somebody might want it to be after I am all dust and ashes.


David

[David Dunlop]

Finally caught up on another little task this morning; getting the stencils back onto the Reels, Cable No. 2 Mk II for the 52-Set.

These reels are identical to the standard, similar reels of this type issued by both the Canadian and British Armies, but like a number of the items Canadian Marconi Company issued with the various 52-Set Kits, they ordered a number of reels directly from a manufacturer, and a CMC Part Number was added into the stencils for these items.

Since the stencils applied to the similar, but more robust reels used with the Aerial 4-Section that came with the 52-Set, were sprayed in a fairly light coat of flat white paint, I decided to go with the same process for this cable reel.

The first step was to trim down the two stencils I had made last year, so they would fit properly on either side of the hub assembly on the free end of the reel, as per the reel used with the horizontal aerial. Once the two stencils were properly trimmed and taped down, I masked off all the exposed areas on the reel with newsprint and applied several light coats of flat white spray paint from a height of about 18 to 20 inches and let the paint more or less float down onto the reel, to minimize any excess spray getting driven under the oil board. It took a few careful passes from several different directions to get a paint density comparable to the original markings on the aerial reel, and 20 minutes later, I was able to remove the stencils and found no trace of overspray anywhere.

Nice to have one more part of the project out of the way.


David

[Chris Suslowicz]

Originally Posted by David Dunlop

Finally caught up on another little task this morning; getting the stencils back onto the Reels, Cable No. 2 Mk II for the 52-Set.

These reels are identical to the standard, similar reels of this type issued by both the Canadian and British Armies, but like a number of the items Canadian Marconi Company issued with the various 52-Set Kits, they ordered a number of reels directly from a manufacturer, and a CMC Part Number was added into the stencils for these items.

Since the stencils applied to the similar, but more robust reels used with the Aerial 4-Section that came with the 52-Set...

Ha. Haha.. Hahahahaha...

I bought some "Reels, Cable, No.2" off eBay, and discovered when they arrived why the MoD had surplussed them.

The idiot manufacturer had mis-read the drawings, and cut the reel cheeks from steel plate of the maximum thickness on the drawing (which I think was supposed to be a pressed-in stiffening rib, though it may have been the soldered-on reinforcement of the reel edging that protected the user from the sharp edge of the tinplate cheek. Either way, each reel weighed several pounds - rather more than the correct design with the full quantity of wire on it.

Thankfully the original waist-mounted cable layer was long obsolete or the unfortunate user would have had difficulty walking in a straight line.

I think I still have one somewhere.

Chris.

[David Dunlop]

Wheels for a railway in your back garden, Chris?


David

[David Dunlop]

I thought a Progress Report on the 52-Set Project would be useful at this point in time. Work is still progressing, but in an ‘educational’ direction for a while.

I have never been one to start something without a plan, as much research ahead of time as possible, and a supply of the necessary parts needed for the work at hand to see it through to completion. It has always seemed more effective to disassemble something once, do whatever is needed to bring it back to good working order and then reassemble it

The work needed on the Sender has gone as far as I can take it at the moment, until I can sort out sourcing all the proper, available components efficiently, to fix what has been found needs attention in one go around. It would drive me nuts if the Sender was sitting in pieces for weeks on end while I bounced from pillar to post getting things done. I know the majority of passive and low voltage circuits in the Sender are in good working order and it is in the HT1 and HT2 circuits where items still need to be addressed.

In order to keep things going with the project at this point, I need to redirect my attention back to the Supply Unit once more. It still has a number of physical issues that need to be fixed/attended to, along with a couple of electrical mysteries related to the Receiver Vibrator Supply section. The Supply Unit, is a very compact design that even the Canadian Marconi Company admitted to in its documentation for the set. Repacking the dynamotor bearings and inspecting the brushes can be done with a minimum of careful disassembly, but is so much easier if they are both free standing on the work bench. To replace the dead Drop Cord, however, the front panel needs to be removed, and to remove the dynamotors, the case surrounding the Receiver Vibrator Supply must be removable from the Supply Unit Chassis, to gain access to the right side mounting bolts of the two dynamotors. That latter issue was what prompted me to focus on the stuck Receiver Vibrator Supply Case last year and get it to work properly. As you may recall, part of that work required removal of the Blower Motor assembly to access all the RVS Case hardware and I took that opportunity to clean and restore the blower components so that all Supply Unit parts that should still be in factory original Gloss Navy Grey, are now in that condition and done.

At this point in time, the only thing stopping work from proceeding on the Supply Unit is the need for correct luminous green decals to put onto the front panel when all other work on the Supply Unit has been completed, prior to final reassembly. As noted upon initial examination of the Supply Unit when it first arrived, the current decals were a 1960’s era remake item using yellow luminous paint, and too small a font. Why the Government at that time went with the most expensive, hard to find colour of luminous paint, instead of the cheaper, more common green, I do not know, but they did. The workmanship of applying the decals was beyond poor and subsequent damage to a number of them means overall, they have to be replaced.

I have now sorted out the steps required to replicate the correct looking decals for the Supply Unit. Making the water transfer decal sheets is now the challenge. Fortunately, the Operators Manual for the 52-Set contains a full front photo of the original decals for both the Supply Unit and the Coil, Aerial Tuning front panel. The challenge is that both are less than one half the required ‘full size’ image needed to work with for replicating, and this is where it gets tricky. Old printed photographs are composed of a mass of small, grey scale dots, which produce the black and white image you see on the paper. If you are not careful when trying to enlarge/blow up these printed photographs, you end up enlarging the dots to the point they become visible and the image breaks down. If you make a digital photograph of the original print image and try enlarging it, you risk the digital image breaking down into its component pixels and once again, the image breaks down.

I am not sure when it came into being, but there is now an area of digital image media known as Vector Graphics. With it, you can convert a digital photograph into a vector graphics format, which completely eliminates any breakdown of the image when it is enlarged. You can take a photograph of a postage stamp and turn it into a 20 x 40 meter wall mural, if you wish.

So last year, when we finally upgraded our 16 year old iMac to a new one, I also bought a vector graphics program and installed it, with this part of the 52-Set Project in mind. It is now time to learn everything I can about vector graphics and working with it. Not sure how long it will take, but I am actually looking forward to learning something new for the project. It will mean, in all likelihood, a reduction in things to post about on this thread for a while. In any event, we shall see what happens.

David