Wireless Set No. 52 Canadian - Project

[David Dunlop]

While picking up a supply of paint strainers last weekend at the local RONA Store, I spotted a couple of paint tins sitting on a lower shelf, so took a closer look at one.

It turned out to be an empty, 1-quart tin, priced at just under $5.00, and it was what I would consider a classic paint tin. No black plastic top and bottom and no interior ‘rubber’ liner on the lid or tin itself; just a coat of varnish. The 1-lb tin of grease that was part of the 52-Set kit popped into my head so I bought one of the tins on spec.

Turns out it is a perfect match for the tin illustrated in the Parts Manual. I had thought the tins might have been painted in the typical horizontal red, white and blue stripes from Imperil Oil with factory markings, but the illustration is clearly a bare metal tin. Probably something that helped keep the costs down for the supply contract during the war. All the identification was probably on the outside of the case of tins and on arrival at whatever Central Supply Depot, the typical small beige paper labels were added to each tin. Not sure who actually applies those labels to military supply packaging.

I will probably end up buying a couple of cartridges of the new replacement grease for the wartime Andoc and transferring it to this tin, when I clean and repack the bearings of the Supply Unit dynamotors.


David

[David Dunlop]

The current owner of this beast was kind enough to lend it to me yesterday so I can cut the six stencils I need so far for the 52-Set Project. Two small bundles of Oil Boards were also made available. The original plan was for me to work at the owner’s location but we realized that would have involved me having to take all the items needing stencils to the machine location to properly space/size/fit each stencil board. It made more sense to get the machine to my place, do the work and return it. That was an interesting exercise.

After a quick basic lesson on how the cutter works, I was able to get the car up to a large overhead door and load the cutter safely into the trunk. It looks innocent enough sitting on my work desk now, but trust me, that 15”W x 21”D x 12”H cast iron mass weighs every ounce of its rated 55 pounds once you have humped it out of the car, 40 feet to the house, down a flight of 11 stairs and across a finished basement to your work shop, without seeing what your feet are doing. The local gym has nothing on that workout!

From what I have read last evening, Diagraph and Marsh are the two sole players in the manual stencil cutting machine business, with Diagraph being the first out of the gate over 100 years ago. There must have been a lot of Patent Licence Dancing going on as both company products are alarmingly similar in looks and operation, and the resulting stencils from both machines would be comfortably interchangeable, assuming both machines were similar vintage. Newer machines from both companies have adopted slightly softer edges to their fonts than were present back in the 1940’s and 1950’s, and the difference is readably noticeable when the two fonts are side by side.

The Oil Board is critical to the long-term good operation of these cutters. There is a central oiling point in the middle of the large Character Wheel. A few drops every couple of years keeps all the mechanical bits in good lube and functioning smoothly and it needs to be cleaned of accumulated dust every couple of months but none of this deals with the cutting die sets. All of these rely solely on the Oil Board to keep their cutting edges lubed and sharp. If one tries cutting standard stationary paper or manila to save money on Oil Board, the cutting dies will plug up with dust, jamb and wear out. The Oil Board is also intended to be an easily cleaned surface once you have finished working with the stencils, so you do not constantly have to recut new stencils.

I will report more as I work through the stencils I need to make this week.



David

[David Dunlop]

I managed to chew my way through a half dozen pieces of oil board while learning how to work with this Diagraph to replicate the existing wartime stencils on all the 52-Set items. Once you have it figured out, the work actually flows quite smoothly. I will assemble and post my working notes shortly, but first wanted to show the results for the three boxes/cases in the 52-Set Kits. I have photographs of two of the boxes/cases to compare to but only a ghost image of the original stencil under newer paint layers on the Case, Operating for the Remote Receiver which did not want to photograph well at all.

There is just enough curl in the oil boards they do not lay completely flat, so I ended up having to hold them up in the air near a white wall to get decent images of them. Hopefully I can get the last three stencils cut this evening.


David

[David Dunlop]

Although these stencil cutting machines are beasts to move, they are surprisingly straight forward to operate. Everything you need is right in front of you, on top of the machine.

When you turn the large Character Wheel, top centre, the red indicator moves to the character you want to select and this places the corresponding character cutting die set at the front of the case, directly below the Operating Lever.

The lower front Table is where you place the sheet of Oil Board. This Table is cast with six stepped ridges, the first at the lowermost edge of the Table and the remaining five continue up the Table under the Cutter Die Set Guard. This arrangement gives you the six rows of text the machine is capable of cutting in a sheet of Oil Board, assuming the piece of Oil Board you are working with is six inches high. You start with the Oil Board at the bottom ridge of the Table, to cut the first, top most, row of the stencil and move up a ridge for each of the remaining five rows.

The lever at the bottom front of the Table raises and lowers the set of rollers that move the Oil Board from right to left across the Table. Lever up, raises the rollers. Lever down, locks the rollers down onto the Oil Board. To the best of my knowledge, there is no ‘Reverse’. The machine will only move the Oil Board from right to left. In addition, the machine will only cut reliably starting at the top row of characters and working down. If you try starting a stencil at a row and then working up, the rollers will eventually arrive on a cut character in the Oil Board, thereby losing contact with the Oil Board and stop moving it.

The ridges on the Table are 0.75 inch high each. This gives a 0.25 inch spacing between each row of characters on the stencil you are cutting and this arrangement is fixed in stone, or in this case cast iron.

You will notice in the attached photograph there are four vertical coloured lines cast into the Table: red, white, red and red. The first three lines are clustered to the left side of the table with a 1.5 inch space between each of them, and the remaining red line is somewhat to the right, three inches away. When you align the left edge of the Oil Board with one of these three lines on the left of the Table at the start of each row of characters you are cutting on the Oil Board, the rows will be left justified, with the first characters of each row directly under each other.

Regardless of the size of the character you are cutting, each character uses a 0.75 inch wide block of space. To get a blank space between words, you only move the Cutting Lever down half way. This covers the easy, single line stencils, or left justified multiline stencils.

Where things get challenging and introduce a dash of basic mathematics to ones though processes, is when you have to deal with multi line centre justified stencils. I was lucky to have photographs, illustrations or actual objects on hand to confirm centre justification existed in the original wartime stencil work on the 52-Set.

I started by printing out each line on a piece of paper, counting the characters in each line (a space is a character) and noting the number at the end of each line. As a simple example, suppose I had a three line stencil and the character count was seven, ten and eight. I would choose the white vertical reference line for the middle, longest row when I got to it.

You will note that the spacing between the set of red, white and red lines to the left of the Table is 1.5 inches. This equals two full character spaces, either side of the white line. If you move the left edge of the Oil board towards the left red line, you are moving the start point of that row of characters to the right on the Oil Board. Conversely, if you move the left edge of the Oil Board towards the right red line, the start of the line of characters moves to the left on the Oil Board.

So the first line of this imaginary stencil is three characters shorter than the middle line (seven versus ten). To centre this first line over the middle line, there must be 1.5 empty spaces either end of this first line. The tricky bit is dealing with the half character at the start of this line. If any character takes up 0.75 inches, then half a character will use up 3/8-inch. So we start the stencil by placing the Oil Board on the lowest ridge of the Table and lining up the left edge of the board 3/8-inch to the left of the white reference line and locking it down. The start point for this line is now one half character to the right. We get the extra full character by only moving the Cutting Lever down half way. You then proceed to cut the seven characters of the first line of the stencil and release the board. Relocate the Oil Board on the next ridge up on the Table and align the left edge with the white reference line and lock it down. Start cutting the 10 characters of this line and release the board. The first line will now be centred over the second line with 1.5 character spaces each end.

Move the Oil Board one more ridge up the Table and align the left edge of it once again to the white reference line. Start this line with a space and then cut the eight characters required and release the board. You should then have a three line, centre justified, stencil.

The manual for the stencil cutter does not go into this sort of detail for some reason, but it is useful to know and worth documenting.

Three more stencils to go. If anything new pops up, I will let you know.



David

[David Dunlop]

This particular stencil is probably the most interesting of the 52-Set stencils I am aware of to date.

As you can see in the photo of the original surviving markings, it is not a true stencil marking, but some form of silk screened product, perfectly centred on the upper left side of the Carriers No. 4. The characters are definitely all 1/2-inch in height, but slightly slimmer, and without the webbing the stencil cutting machine produces. The line lengths are a very close match but the overall height of the three lines on the stencil is 1/4-inch lower than the actual markings on the Carriers No. 4. Also, there is no means of cutting a lower case, underlined ‘o’ on a stencil machine.

When I started this project, I assumed Canadian Marconi Company built everything for the set but actively contracted out for components. I am not sure why I made this assumption considering I knew Northern Electric had built the Supply Units for the earlier No. 9 Sets made by CMC.

I have now learned RCA and Philco were clearly providing major sub assemblies and accessories to CMC for the 52-Set as sub-contractors. The sheet metal work required for the chassis of the Receivers, Supply Units, Senders and Coils Aerial Tuning (and probably the Remote Receiver Case) would certainly be within the capacity of Marconi’s shops to have produced, and with the exception on the Remote Receiver Case currently soaked with NATO Green paint, all the other chassis bear CMC inspection stamps punched into the metal.

The Carriers No. 4 is a somewhat different beast. Although the basic three compartment box is the same gauge metal as the chassis items, the Carriers No. 4 has some very heavy duty steel formed and fitted to it. It would not surprise me at all if the Carriers No. 4 were sub contracted out by Marconi for production and whatever company manufactured them used silk screen style tools for the markings. When I eventually get to the point of restoring the Carriers No. 4, perhaps some stampings will show up on the metal parts somewhere that will shed more light on this bit of 52-Set production.

In the meantime, I now have a stencil I can use for this marking, if all else fails, and enough time to explore silk screening options a little more to see if there is a way to easily replicate this item.


David

[David Dunlop]

This test meter arrived in the mail yesterday afternoon.

In the original Issue 1 of the F524 2nd to 4th Echelon Work Manual for the Wireless Set No. 52, when doing calibration/alignment work on the Sender, one had to construct a Dummy Load from a number of switches, capacitors, resistors and an ammeter to tune against. However, in the 18 January 1961 Revision 2 of F524, this Marconi Instruments Ltd TF957/1 Wattmeter was available to do the work for the Low Power output work on the Sender. It was simply connected between the Aerial and Ground, along with a 120 V, 150 W Light Bulb and away you went with your test work.

At the same time I had discovered this information, this meter popped up for sale on eBay out of Alberta. Quite a surprise when it arrived. I was expecting something in size comparable to a typical RCA, or Simpson, Multimeter of similar vintage, but this 15 lb, 12 inch high by 10 inch wide by 8.5 inch deep beastie showed up instead. Quite a size for a passive piece of test gear.

The meter is a Marconi Instruments Ltd, England product from 1957 and the TF957/1 was the export version of the TF957 for the North American Market. The main differences are the use of BNC terminals for the 1-Watt and 25-Watt test connectors and both circuits being standardized to 52 Ohms. This one was owned by the Canadian Army and probably disposed of shortly after 28 April 1994. That was the meter’s last calibration date with the next one noted as being due 15 July 1995. Missing the extension cable for the probe, one cover latch assembly and the Instruction Manual/ Card, which probably stored inside the cover with the probe and extension cable.

As much as it would have been fun to build the original Dummy Load, this is going to be so much easier.


David

[David Dunlop]

Two sets of Stencil Brushes arrived in today’s mail. They are natural bristle, square cut and small enough to work with the ½-inch stencils I recently cut for the 52-Set Project.

I toyed with the idea of tracking down an original stencil brush, the type with the paint reservoir handle, but they would be much too large for such a small sized stencil and with the oil board being close to 1/32-inch thick, I would likely have issues getting paint easily into the cut-outs without serious risk of too much paint suddenly blobbing under the oil board.

From what I have read on the current crafting media, it is far better to use very little paint and build up the density you need in several layers.

Fortunately, I have enough ‘goofed’ oil board stencils to practice on until I get the process right.


David