Wireless Set No. 52 Canadian - Project

[David Dunlop]

I had to pass on one of these last year, as it simply wasn’t in the budget at the time it showed up for sale, However, a few weeks ago, a gentleman in Kent, England had a post on the internet with a number of NOS ones for sale.

My Daughter and three Granddaughters had given Papa some Mad Money to put towards my WS No. 52 Project for Xmas, so I was quite pleased to be able to order two Holders to replace the ones removed from the Remote Receiver and Main Set Receiver when still in service.

It’s always fun to find old stock with original packaging and these two holders were no exception. Each still has its factory tag attached with a small run of hemp cord. The tags read:

ZA/4250 HOLDERS, Watch, Multi-purpose Part, Qty 6


David

[David Dunlop]

This is undoubtedly going to be a long project and I am carefully avoiding any thought at all about an anticipated completion date for it. The bright side of this, however, is the lack of stress about ‘finishing on time’. It will be done when it’s done.

The other nice thing about this approach is that it allows one to focus on and enjoy the little milestones as one reaches them. They don’t get brushed aside because of looking so far down the road at ‘meeting the deadline’.

I reached one of those little milestones this morning when I was able to reinstall the two Holders, Watch on the fronts of the Receiver and Remote Receiver. These were removed back in the early 1960’s, when the receivers were still in service and the three empty holes at the top of each panel were a constant reminder of the missing parts, and they were the only missing parts on both receivers.

There are still a few rusty/worn hardware items I want to swap out for better condition ones on the main set receiver and a few other physical things to attend to, but it is finally getting close to the same condition physically as the remote Receiver.


David

[Bruce MacMillan]

David, very nice work. I hope that you will have it operational for QSO's on the 75th anniversary of D-day .

Your dedication to restoration is to be commended.

[David Dunlop]

Although this thread is supposed to be a simple documentation of what I am doing with regards to restoring a Wireless Set No. 52, I have come to realize that it is also indirectly documenting things I learn about the 52-Set as I plod along. That is probably a good thing in that there seems to be a lot to discover. Typically details never discussed or illustrated in the manuals pop up and I suspect a lot of other 52-Set owners out there are unaware of them either.

Case in point this week. Reg Hodgson, in Edmonton, has started a restoration/clean up of his 52-Set and sent me the attached two photographs of what he discovered. Reg has had many years of military vehicle restoration work behind him and has developed an eye for detail. He is working on his Carrier No. 4 at the moment. His was a lucky one. No aggressive strip down of the original paint (wrinkle No. 2 Brown in this case), just a simple spray over of NATO Green.

When he removed the Coil, Aerial Tuning No. 2 mounting rails on the right hand side of his Carrier No. 4, he noticed a lettering shadow underneath the NATO Green. A little careful sanding later and the attached stencilled ID turned up sitting on top of the factory original wrinkle No. 2 Brown. This marking would be hard to spot with the Coil rails in place and utterly impossible to see once the Coil box was mounted on the side rails.

I was delighted Reg found this marking as I can now look for it and replicate it if necessary, if and when I find my own Carrier No. 4. It is also now referenced for anyone else in the future.

It was also nice to see this marking, as it is very similar to what I recall seeing once on a 52-Set Remote Receiver Case. The identifiers, of course, would be different for the Remote Receiver Case, but I am pretty sure now that marking was also centred on the side of the case, below the handle.

David

[David Dunlop]

This past weekend, I was able to replace the Handles, No. 72, and its related Screws, Clamping No. C2, on the Tuning Dial of my Main Set Receiver. Their original look can be seen in the left hand photo in Post 149 of this thread.

I had mentioned in an earlier Post that the Handles unit was badly chipped and dented and the Clamping Screws were really showing their age now. So replacing them all with the ones from my spare receiver made a lot of sense. A side project spun off of this related to the Slow Motion Drive Assembly on the Main Set Receiver, but I will deal with that in a separate Post shortly.

Any work on the tuning dials of the 52-Set (or even the 19-Set and any other wartime wireless equipment using this style of tuning dial) can be a very intimidating task. The four Clamping Screws operate the Flick Mechanism that enables the Wireless Operator to preselect two different operating frequencies, that once set, can be dialled in very rapidly. These are the ‘A’ and ‘B’ (Red and Blue) frequencies highlighted on the front panel of the wireless set. Typically, one frequency would be for daytime use and the other for nighttime.

To make all of that work, there are four separate components behind the Handles, the Clamping Screws pass through or screw into. Two of these pieces are Washer, Clamping, Front and a Washer, Clamping Rear. The 19-Set Manual refers to these as ‘Plates’ for some reason. I have added a photo of the Washer, Clamping, Front.

There is a bit of free play as to how these two pieces sit in the tuning assembly. They can move around a little and it only takes a little movement for the holes to shift out of alignment once the Clamping Screws are removed. So you do not want that to happen. You want gravity to work for you, not against you when doing this work and to that end, I would strongly recommend you lay the receiver on it’s back, on a couple of supports to protect the rectangular connector on the back. Once the receiver is lying flat on its back all the fiddly bits will stay put. If you are still nervous about doing this work, another great tip I got from Jacques Fortin, is to get hold of an early version of the Clamping Screws used on the Mark II Wireless Set No. 19: The straight ones with the slot in the end. These were designed and intended to allow the Handles No. 72 to be removed and replaced without losing the hole alignments inside the Flick Mechanism. Simply installing one of these older Clamping Screws and running it home will prevent serious hole misalignment.

To remove the Handles No. 72, first unscrew the grub screw on the lower side of the handle. This will require a small jeweller’s slotted screwdriver, not a Bristo or Allan Key. Then unscrew and remove the large screw in the centre of the Handle No. 72. Then comes the tricky bit.

There is a pair of Springs, Steel, Wire No. 1 (ZA 14271) located in slots on either side of the Handles No. 72. These springs were designed to put tension on the sides of the Clamping Screw shafts to prevent them from accidentally falling out of the Handle if they were completely unscrewed. There is a very small pivot pin located centrally along each Spring. These create the tension against the Clamping Screws when they are installed in the handle. When the tension is gone (the Clamping Screws removed from the system) these small pivot pins are free to fall out of the bottom of the Handles No. 72 when you try lifting it off the tuning dial. To prevent this from happening, grab the ends of one Spring with the index finger and thumb of one hand and do the same with the other hand on the other spring. Then pull the ends of both springs outward slightly from the centre of the Handle, while maintaining enough grip on the handle to lift it clear of its mounting shaft. As it comes clear, keep the tension on the springs and turn the Handle No. 72 on its back before putting it down on your workbench. This will keep the pivot pins safely in their two holes. See the attached photo of the back of the old Handles No. 72 I replaced. The two holes are at the ‘9’ and ‘3’ positions and clearly these pins have been lost more than once over time with my spare receiver. The one at ‘3’ is too long and the end of the pin shaft has been punched to permanently retain it. The pin that came out of the ‘9’ position is not an original pin but a section of screw shaft cut down to fit. Wow! The stories parts can tell sometimes.

For reassembly, make sure the holes for the four Clamping screws all line up. A small knitting needle can be used to tweak any slightly. From it’s upside down position on your workbench, do the same finger trick with the tension on the springs to pick it up and turn it over to drop onto its shaft. Only release the tension when it is down all the way. It is a good idea at this point to replace the four Clamping Screws. There will be a slight bit of resistance when the screws first encounter the spring but they easily push past that point. When you know they are all run home, replace the large central screw. Once the Handle No. 72 is fully seated, retighten the grub screw.

Last photo is the Main Set Receiver with the nicer looking Handles No. 72 and Clamping Screws installed.

And that’s all she wrote this time,

David

[David Dunlop]

In my last post I mentioned some spin off work for the Slow Motion Tuning Drive turned up while I was replacing the Handles No. 72 on my Main Set Receiver.

I had noticed a while ago the Slow Motion Drive seemed a bit stiffer than it should have been to operate and when the Flick Control Lever to the right of the tuning dial was in it’s lower FLICK position, I needed two hands to turn the dial, which by rights should turn very freely with one hand with the control lever turned to that mode. My thought at the time was that since the Slow Motion Drive worked, but was very stiff, the problem was probably with one of the tuning shaft support bearings, fore and aft on the tuning condenser assembly. While working on the Handles No. 72, I decided to take advantage of the strip down and remove the large tuning dial to give it a proper clean. This necessitated removal of the Slow Motion Drive Assembly at the bottom of the dial. This is another of those tasks that can be intimidating because of the Bracket and Spring Assemblies No. C1 (ZA/CAN 0233) the Slow Motion Drive is mounted in and the fact there is a lower arm of the Flick Mechanism connected to the Slow Motion Drive one has to be aware of while removing and installing the drive unit. Again, this is another bit of work that you should let gravity help you with. Place the receiver on its back before you start.

The first two photos are of a standard drive and a Slow Motion Drive assembly. The stud on the lower right hand side of each it what engages into a large, self-locating V-Slot on the end of the lower Flick Lever. When everything is installed, and you turn the Flick Control Lever to the ‘FLICK’ position, the lower Flick Lever (which is spring loaded to keep it under tension, pushed the right hand side of the Drive Assembly away from the rim of the large tuning dial. The allows the operator to grab the Handles No. 72 and turn the dial rapidly to one of the preselected frequencies. When that position on the dial is reached, an Upper Flick Lever, coming from the Flick Control up to the two Indicator Flags Mechanism drops the appropriate Indicator Flag down for either the A or B Frequency being selected.

Because of the orientation of the Lower Flick Lever, and the fact it is under spring tension, if there is no Tuning Drive in place for it to engage, it will automatically swing to the left, across the small rectangular opening in the panel behind the drive assembly, when you remove the drive. Don’t look for it on the right side later. It won’t be there.

Before you start, make sure the Flick Control Lever is in its middle SET position and leave it there. First step it to remove the knobs from the drive. Then remove the long pivot screw at the left side of the Bracket and Spring Assemblies. It is a good idea to keep a thumb on the assemblies, just to the right of the pivot screw as you remove it. To keep everything in place until you are ready. You will notice as the screw comes out of the panel, the Bracket and Spring Assemblies relaxes and a small bend shows up along the lower edge. At this point, slowly lift the Assemblies away from the panel. About 1/8-inch away from the panel you should feel the locking stud, about ½-inch to the right of the pivot pin pop free of the panel. When it does, slowly move the Assemblies up and to the left at a shallow angle. You should notice the Lower Flick Lever following along for a while and then disengaging and swinging off to the left of the rectangular hole.

To replace the complete Drive, Bracket and Spring Assemblies No. C1, start by putting the long pivot pin in place to keep the two parts together. With a small little hook, retrieve the Lower Flick Lever from the left side of the little rectangle. As you move it slowly to the right, you will see the large V-opening appear with a rounded apex to the V. Insert the stud on the lower left end of the tuning drive into the V-opening, left the lever engage it and move the entire assembly into position such that the long pivot screw can be engaged in it’s hole and threaded home. The manuals will tell you to run the pivot screw completely home before the next step, but that just make the next step that much harder for you to complete.

The small locking stud to the right of the pivot screw rests very quickly on the top of the panel face. If you run the pivot screw completely home first, that small stud really digs in and you are making a lot more work for yourself. Don’t worry about getting the rim of the large tuning dial into its slot on the central pin of the drive assembly. If you miss it initially, it should pop into place as you tighten to pivot screw.

The last step the manual will advise you to do is insert a small slotted screw driver under the Bracket and Spring Assemblies, engage the end of the small locking stud and push it up about one half inch until it pops into its locking hole. I find a much better solution is to use a thin steel putty knife as shown in the third photograph. If you have to, remove any switch knobs in the area to make things easier for you. I usually tighten the pivot screw down just far enough I can slide the putty knife blade under it easily. The really nice thing about the putty knife is it has a wide blade and you will not miss finding the small locking stud. That spring on the Bracket and Spring Assemblies No. C1 has a surprising amount of tension in as you move it closer to its panel hole. The bottom edge of the assembly should be perfectly straight when you get to the hole. Once it has dropped in place, remove the putty knife, finish tightening the pivot screw, reinstall the tuning knobs and any others you had to remove and you are good to go.

Sorry for the length of this. Hope it proves helpful.

David

[David Dunlop]

The Crystal Calibrator Panel on my Main Set Receiver was very badly scratched up, including several across some of the lettering, so I decided to replace it with the panel from my spare receiver, which had only a couple of small visible paint chips and a few larger ones around the perimeter that is hidden under the upper receiver front panel. The first three photos show the original panel, the original replacement panel, and the refurbished replacement panel. It turns out that Testors 1139 Semi-Gloss Black Model Paint is a near perfect match to the black paint Canadian Marconi used on the calibrator panel here.

The Crystal Calibrator is a complete, self-contained sub assembly that is mounted to the receiver chassis at some point on the receiver assembly line, by means of four small angle brackets, two either side of the rear chassis plate of the calibrator. See the fourth photo in this post. Swapping out the calibrator panel is, fortunately, a purely mechanical task, that is easy enough to do with a little forethought.

The first step is to lay the receiver on its left side on your bench as this makes access to all the necessary hardware much easier, and if any hardware falls loose, it will not disappear into the bottom of the main chassis. Then remove the calibrator switch knob. You should then notice this switch has a small key tab just to the left of the switch shaft that sits in a small hole in the panel just above the ‘FR’ of “FREQ CHECK”. Then, carefully unscrew the large hex nut securing the switch. It should have a large, external tooth lock washer behind it. Be gentle as this has been tightened against 75 year old paint that might have been bruised and you do not want large chips to pop off if you can avoid it.

The next step is to undo the ground terminal at the lower end of the 5 Watt 8 Ohm Lamp Resistor. Shown in the first two photos of the following post. You can then remove the two slotted, pan head self-tapping screws on the underside of the calibrator panel, shown in the third and fourth pictures of the following post.

Next remove the two screws on the upper front of the calibrator panel, above the Holders, Lamp Assembly. You can now gently pull the panel assembly forwards just enough to access the centre screw terminal on the back of the Holders, Lamp Assembly with a small socket. There is a small trick to this, however. Loosening the hex nut on the centre terminal to remove the connector also loosens the Lamp Socket inside the Holder and it will start to turn with the hex nut you are trying to remove. So before you start trying to undo the hex nut, remove the red lamp cover from the front of the Holders, Lamp and place a fingertip on the bulb inside with enough pressure backwards to hold the bulb and socket still while you undo and remove the hex nut.

To reassemble, do everything in the reverse order.

David