#1081
|
||||||
|
||||||
Quote:
Quote:
There was (briefly) a "Watch W/T Non-Magnetic" which was actually _cheaper_ than the GSTP watches, having a chrome-plated iron case to screen the movement from the magnetic fields of generators and rotary converters in the wireless sets. They were later found to be unnecessary (and also less accurate, being cheap). Quote:
Quote:
Quote:
Quote:
The "Signals Office" used a GSTP watch but didn't adjust the time very often - they kept a record of the "error" relative to the 21:00 time broadcast from HQ and (presumably) adjusted the watch when the difference became too great. (Saves wear and tear on the watch, and they'd just add/subtract corrections in the paperwork, as required.) I have a few "B" watches, some GSTP ones, an Australian W/T watch in a brass case (that some idiot removed all the black paint from and _polished_), and a Watch W/T Non Magnetic (with Roman numerals on the dial). I've also got my father's watch (which I must get restored) that _was_ used with his WS19 (because the issue watch was unreliable), and that was a present from his uncle (who was a Major in the army and ended up in Katyn). There's an overview of military watches here:https://royalsignals.org.uk/photos/watch.htm Best regards, Chris (G8KGS) Junior Password Gnome |
#1082
|
|||
|
|||
Yikes, Chris!
First of all, thanks for taking the time to post all that information. The ‘humble’ GSTP pocket watch is a far more complex topic than I ever imagined. When I was trying to find appropriate watches to mount on my wireless sets a few years ago, I did run across a number of such watches with names on their faces, but confusion set in quickly with many comments being found on this that these were maker names and other comments they were just the names of ‘bespoke’ military tailors where officers would go to get kitted out for custom uniforms. Out of that confusion I assumed makers were unlikely in wartime to advertise themselves, so all those names were more likely just tailors who did not think the officers would be dumb enough to get captured. Beyond that, most of my research information focused on a handful of North American watch makers, as the most likely candidates to have produced the Canadian Army pocket watches. Interestingly, the steel cases came up in the NA readings I found regarding none magnetic watches with comments they were not that good. Three or four very odd alloys were discussed that had been developed in the years prior to WW2 for making the watch main springs and other movement parts that seemed to be quite effective. These alloys had very odd names that made me wonder if they had not been discovered while excavations were underway in the Mile Forts along Hadrians Wall. Sorry to hear about the polished brass watch holder. I have also seen that done to wartime military compasses, sniper scopes and binoculars ‘to restore their true value’. David |
#1083
|
|||
|
|||
I think Waltham and Elgin were the major American suppliers of watches (certainly to the British under Lend -Lease), and they were just their standard watch. My suspicion is that the Canadian WS19 Supply Unit No.2 had the watch holder moved to the front of it (instead of being on the set) was to solve the problem of tall winding stems.
The Australian watch (not a watch holder) should be finished in black "opticians enamel", I think, but mine has been "got at" by the Mad Brass Polisher[TM]. There's worse: I've seen optical instruments polished and CHROME-PLATED at some events! (Theodolites, heliographs, Instruments Flash-Spotting, and so on - they would never have been accepted for service with that finish.) On the subject of Westclox (Western Clock Co.) - they also made daylight signalling lamps as well as morse keys for the WS19. Best regards, Chris. |
#1084
|
|||
|
|||
Supply Unit Update
Another step closer to starting work on the Supply Unit.
These two cartridges of grease were picked up today, destined for the four bearings in the two rotary transformers. This grease follows the lineage of the original wartime grease used up until the 1970’s and discontinued by Imperial Oil shortly afterwards. The original Andoc-C was a Grade 4, high temperature grease for electric motors. Imperial/Mobil no longer makes a Grade 4 grease, but their Polyrex line is still intended for this equipment today. Polyrex EM 103 is a Grade 3 grease but very hard to find in cartridges at a reasonable price. This Polyrex EM is a Grade 2 version rated to be stable up to 499 degrees which should be more than adequate for running the 52-Set on short term transmissions at standard room temperatures for the rest of its life. The tricky bit will be flushing out all the old sodium based original grease from the bearings before repacking them with this newer lithium based product. I do not anticipate using very much of this grease, but the cost of two cartridges locally for pickup was well below the single cartridge price of this stuff I could find anywhere on the web. Leftovers will be transferred to the one pound tin and labeled, as part of the supplies for the 52-set shown in the Parts List. David |
#1085
|
|||
|
|||
WIRE, Electrical, R4, Mk 1 WB 1057
I think I have mentioned it before, this project would have been better started 50 years ago when 52-Set equipment was much more readily found. But then what is a project without challenges.
One of the items issued with the Remote Receiver and stocked in its Operating Case was a 100 foot coil of antenna wire; Wire, Electrical, R4, Mk 1. Next to impossible to find today under that specific identification. A little over a year ago, however, I stopped searching for the official military named product and started searching the internet using the actual description of the cold draw, stranded copper wire, provided in the Master Parts List for the 52-Set. Not only did I discover this product is still alive and well and in production, but 100 foot coils can still be purchased from a number of Amateur Radio suppliers in the United States, or directly from the primary manufacturer, Davis RF, also in the USA. Most pricing falls in the low to mid $20.00 USF range but pay attention to shipping costs. Some will hit four times the value of the goods, or more. I picked up my order in Pembina, North Dakota today and was delighted to find the coil was wound to within one quarter inch in diameter of the size of the coil illustrated in the Master Parts List. The weight of this coil comes in at 1.375 pounds and it was nice to finally have one of the items stored in the left side compartment of the Operating Case, actually in place. David |
#1086
|
|||
|
|||
Quote:
Quote:
The "ready made" aerials seem to have been constructed without much attention to detail: I've got at least one where the first section (of something intended to replace the "set of six" wire aerials) is ten feet too long - making it unusable for the intended role. (One of the other sections is ten feet short, so it's a cutting error during manufacture, but it won't match any settings provided on the standard tuning charts - this may be why it survived WW2.) Best regards, Chris. |
#1087
|
|||
|
|||
Hello Chris.
I checked several references on hand for this particular wire and none provided any notes on the lay of the stranding. Also, as brilliant a job as the wartime illustrators did with the Master Parts List, the thinness of the 14 gauge wire was beyond their ability to detail the look of the windings. Our scanner is currently sulking so I cannot add an image at the moment. The illustration does show, however, that the last foot of wire is wrapped around the coil a couple of times, pulled back up the coil about six inches and wrapped off around the coil once more. This forms a kind of handle the coil could be carried with and the opposite side of the coil fans out slightly, since it is not secured. I suspect that when the coil of wire was packed in the Remote Operating Case, the open end of the coil went in first to keep it all in place, with the 'handle' at the top for easy retrieval when needed. This modern coil I got used electricians tape to secure the coil and I have seen others using plastic twist ties. It would be interesting to compare original British wartime 19-Set Horizontal Aerials to Canadian made ones. The tighter you wrap the stranding, the more copper wire gets consumed, so a finished 100 foot run of stranded wire will hold considerably more wire than that when done. Actually, the central core wire would be the only one to be 100 feet long. the other six wrapped around it would all be longer. If you needed to conserve copper during the war, loosening up the wrap in stranded wire would certainly help. One would have to be careful, however, as if the concentric wrap is loosened up too much, it will degrade quickly into a 'bunched' wrap, which can become a complete rats nest to work with in no time. David |
#1088
|
|||
|
|||
decades ago I worked for a Canadian electronic distributor (Cam Gard Supply based out of Winterpeg) and we sold miles of stranded aerial wire. Looking back through the catalogues I saved the only info was that your choice was 7/22 or 7/24 stranded. The twist didn't seem critical.
|
#1089
|
|||
|
|||
Quote:
If I saved a copy it's on a computer with a dead power supply (that's buried somewhere in the "I may want to resurrect this at some point" pile). Shortly after I jokingly commented that "We ought to take a copy of the old battery specifications to reduce our load on their server" (but thankfully not before I had copied everything we were likely to be interested in) the Defence Standards website first deleted all the obsolete specifications, and later made the site private, requiring authorisation to look at anything. Quote:
Quote:
Best regards, Chris. |
#1090
|
|||
|
|||
COIL, Aerial Tuning No. 2 A ZA/CAN 4725
It has been an interesting year for this project, with just a few select items purchased for it, and a lot of thinking about the next steps. I started the year with two options for goals, one centred on the Supply Unit and the second on the Coil, Aerial Tuning No. 2 A. Both of these require working with solvent based enamel paints which required outdoor spraying in the garage or driveway. Both require application of the new replacement phosphor luminous waterslide decals, but in the final analysis, the Coil won out.
The Supply Unit requires extensive physical repairs and some electronic. The decals to replace number seven in total across the front panel and the big factor is little documentation for the work required to clean and repack the bearings in the two rotary transformers. By comparison, the Coil assembly is in perfect working order, still needs the front panel repainted with the enamel paint, but has only two decals to deal with which makes a better option for getting that work right before tackling the Supply Unit. The wood is also in very good shape. Another important factor is I have just enough Flat Army Olive paint left over from restoring the three Boxes/Cases for the 52-Set that the finished Coil assembly will match the other wooden items perfectly when done. The only real fly in the ointment is that this Coil assembly was painted NATO Gloss Green both inside and out, which means a full strip down of all the metal fittings and a lot of sanding in a confined box. More outdoor work but the sunshine will help. I do have another Coil carcass, with only the exterior painted Gloss NATO Green, but the woodwork is shot with large chunks of wood missing, badly stripped screw holes and major cracks in the panels. Some key electronic pieces are missing or badly damaged inside as well. So the chosen Coil assembly is now on the work bench ready for me to disassemble and log in all the parts so they all go back where they came from when finished. First photo is said item and the others are of the damaged second Coil. David |
#1091
|
|||
|
|||
COIL, Aerial Tuning No. 2 A. ZA/CAN 4725
Stripping down the Coil, Aerial Tuning No. 2 A is a relatively straight forward process. If you just need to remove the complete chassis from the case for an inspection, or a minor cleaning, the four steps to do so are nicely explained on Page 139 of the Working Instructions manual for the 52-Set.
However, if a full tear down, including removal of the front panel from the chassis is needed, you will have to ensure you dial the Coil Tuning Counter back to its ‘0000’ Start Position and make sure it stays that way throughout your work. It is important to keep the coil and its counter in sync with each other, while disconnected from each other. The first step after setting the Counter to ‘0000’ is to remove the 10, 3/4-inch, RH slotted steel wood screws securing the wooden back to the case. My approach has always been to identify everything and put it back where it came from during reassembly. Built into this process is the ability to find damaged items during disassembly and getting them fixed, or replaced, before everything goes back together. During reassembly, I also know the parts should fit just fine because they did when they came apart and I am not about to try and put a stripped item onto a perfectly good item and strip it in the process as well. May seem like an excessive process, but it has worked for me for decades. You can see in the attached photos that the NATO Green has been applied in a very thick coat inside and out on this Coil Assembly. However, the possible bright side is that there are a lot of large chips in the NATO Green paint on the inside of the back cover, so the prep work during the repaint mat not have happened and this paint might come off fairly easily, when I get to that point. With the wooden back out of the way, the next step will be to disconnect the three leads for the Aerial feeds in the bottom rear corners and the upper right rear, shown in the last photo. David Last edited by David Dunlop; 22-09-24 at 20:13. |
#1092
|
|||
|
|||
COIL, Aerial Tuning No. 2 A ZA/CAN 4725
The second step in removing the Coil chassis from its case is to find the three leads, pointed out at the end of the last post. They are all 3/16-inch braided and tinned copper loom with ring terminals on the ends connected to the two wing nut terminals at the bottom, either side of the case, and the Lead In Terminal on the upper left side of the case (when viewed from the front). All of the electrical items on these three fittings are zinc, or cadmium, plated brass. A 3/8-inch spanner is probably the best tool for removing the hex nuts on these three fittings. The access to the Lead In Terminal is quite tight and the refitting of the hardware will be the most challenging with it.
I am not certain what sort of lock washer is supposed to be used on these three terminals. There was none on the Lead In Terminal, probably because of the limited access. The wing nut terminal below the Lead In had an external toothed lock washer that looked a bit too large to do the job. The wing nut terminal across from it had an internal toothed lock washer that seemed quite at home there. And, of course, none of this hardware has survived on my parts Coil assembly. The first two photos show the before and after views of this hardware removal. The last photo today shows the locations on the bottom of the Coil case where the three screws with flat washers are to be found. these come into play with the third step. While we are here, however, take a look at the set of brass gears in the tuning mechanism on the centre left side of these photos. They have accumulated a coating of green copper salts since the sets 1966 overhaul, but the rest of the chassis and interior of the wooden case appears remarkably free of any other oxidation, or damp rot in the wood, and as I noted before, this Coil assembly performs perfectly electronically. David Last edited by David Dunlop; 22-09-24 at 20:15. |
#1093
|
|||
|
|||
COIL, Aerial Tuning No. 2 A. ZA/CAN 4725
Step 3 in the removal of the Coil chassis assembly from its case is to remove from the bottom, the three screws that have washers, pictured at the end of the last post.
It was a little disconcerting to see that whoever last fitted this hardware to the case had run these three screws down so hard, the flat washers had cut into the pine board so hard the outer faces of the washers were actually flush with the surface of the board and the wood was coned inward noticably around each of the three screws. Note the first two photos. the concern here was that the base of the coil assembly these three screws are securing to the bottom of the case, is not metal. Rather, it is a mere 1/4-inch plate of brown phenolic resin. There was a very real possibility the overtightened screws could have torqued the threads they cut in the resin so much that the threads would simply strip out of the holes when these screws were removed. Fortunately, all three screws came out smoothly and there was no sign of resin dust or particles stuck to the screws. These cones in the wood will have to be filled in and levelled, and the flat washers carefully re-flattened when reassembly takes place. The three chassis mounting screws are 3/4-inch, RH, slotted self-tapping machine screws with a 1/8-inch diameter shank and a 20 thread pitch. I have run across 1/4-inch long versions of these screws in wireless equipment over the years which have a small V-shaped notch at the tip. These longer screws do not have that notch for some reason. The threads just run out about 1/16-inch from the tip. The flat washers are 3/8-inch OD with a 1/8-inch diameter centred hole. At this point, the coil chassis assembly is only secured by six screws around the perimeter of the front panel. These six screws thread into six small steel brackets fitted around the inner edge of the case, each bracket held in place by a pair of small machine screws and hex nuts. See the last photo of my Parts Coil to get an idea where the last removal step is headed. David |
#1094
|
|||
|
|||
COIL, Aerial Tuning No. 2 A. ZA/CAN 4725
As noted, with the removal of the required six screws from the front panel of the Coil chassis assembly, it is now ready to be removed from its case. The first photo here shows these six screws removed. These screws are a zinc, or cadmium, plated 8-32 x 3/8-inch RH slotted machine screws.
The designers at Canadian Marconi Company seem to have thought of everything with the 52-Set. The coil chassis is quite heavy and rests on a large plate of 1/4-inch brown phenolic resin. This is an important insulator for the coil assembly and can be damaged, so the designers added a sheet of green felt to the bottom to the Coil Case for the chassis to rest on and this also makes it quite easy to slide the chassis in and out of the case. To extract the chassis from the case, it must be slid forward to release the front panel from its recess. this requires a forward movement of 1/4-inch. The safest place to push the chassis forward is to place a finger on each bottom corner of the phenolic resin chassis plates where the side and bottom plates meet at the rear of the assembly. See the second photograph. Apply equal pressure to both sides and push slowly. Remember that bottom central bracket I pointed out earlier that the front panel is secured to, in Post #1093? The one with the gap cut out in the resin plate around it? The gap behind the bracket and the bottom resin chassis plate happens to be 1/4-inch. When the resin bottom plate hits this bracket, the lower edge of the front panel will have just cleared the lower lip of the wooden case and will drop down just enough to allow the top edge of the front panel to tip away from the upper lip of the case. You can then put your fingers under the lower edge of the front panel and lift it all up enough for the bottom phenolic plate of the coil chassis to pass over the bracket and you can carefully slide the entire chassis assembly out of the case. The third photograph shows the green, felt pad clearly in the now empty case and the last photograph shows the Coil chassis assembly now sitting on its own. Time for a glass of wine. David Last edited by David Dunlop; 23-09-24 at 04:40. |
#1095
|
|||
|
|||
COIL, Aerial Tuning No. 2 A. ZA/CAN 4725
Well the first discovery about this Coil assembly with it finally out on the bench for a closer look, was a very positive one.
What looked like a very odd oxidation on the brass gear set for the coil tuning turned out to be a very nice distribution of a medium weight grease which was in excellent condition. Probably applied back in the 1966 Workshop overhaul for the set. The grease shall stay. It has earned its place. David Last edited by David Dunlop; 24-09-24 at 00:39. |
#1096
|
|||
|
|||
COIL, Aerial Tuning No. 2 A. ZA/CAN 4725
The design of the Coil, Aerial Tuning No. 2 A is slowly revealing itself, in spite of not much being said about it in the documentation for the 52-Set. The only technical references it gets are that it is not to be used at all above 10 Mcs and the Sender is to be connected directly to the aerial in use, and, that it is fully interchangeable with the Coil, Aerial Tuning No. 2, issued with the Wireless Set No. 9 Mk I Cdn.
One thing that has now surprised me, because I have missed it for several years now, is that the front panel for the Coil is cut from 1/8-inch Aluminum plate whereas all the other components in the 52-Set have front panels cut from 1/16-inch sheet steel. I am glad I now found this out as I have no primer for working with aluminum when it comes time to repaint the Coil front panel. That product is now on my ‘To Be Purchased’ list. David |
#1097
|
|||
|
|||
COIL, Aerial Tuning No. 2 A. ZA/CAN 4725
While inspecting the Coil I am using for the 52-Set, I found ‘3978’ stamped in blue ink on the bottom side of the phenolic resin base of the coil chassis itself. I then found the same number stamped on the outer surfaces of the resin left and right side panels. See the first three photos. I am thinking this might be a Production Control Number used by Canadian Marconi Company during the manufacture of these coils, in a similar manner to the hand written four digit numbers found on the inside chassis surfaces of the other set components. The only other stamped marking I have found so far is the part number for the coil itself, CMC 119-521, which was stamped along the left side edge of the coil drum as shown in the last photo.
Now I have to see what I can find on the parts coil assembly. David |
#1098
|
|||
|
|||
COIL, Aerial Tuning No. 2 A ZA/CAN 4725
My parts coil revealed the number ‘8798’ stamped on the same parts as the four digit number that was found on the Coil assembly for the 52-Set, as per the first three photos.
The main difference was the Part Number for the Coil itself was not along the left edge of the drum, but now located on the left side plate of the drum. See last photo. So if these numbers are indeed Production Control Numbers, then this Coil assembly came down the line a lot later than the first one. Is the new location for the coil Part Number as production change for some reason, or just a fluke? David |
#1099
|
|||
|
|||
COIL, Aerial Tuning No. 2 A. ZA/CAN 4725
For such a small, and electronically simple component of the 52-Set, this coil assembly holds an amazing number of mysteries for me and they just keep popping up!
In fairness to the Engineers and Designers at Canadian Marconi Company 80 years ago, a fair bit of these mysteries are probably directly related to my limited practical and theoretical electronic knowledge related to this calibre of wartime wireless equipment. The first, and still current mystery, revolves around the existence of the small cylinders found mounted just below the tuning gear drive assemblies on the right side plate of the coil chassis as per the first photo. They are not physically connected to any circuit in the entire coil case, just the 1/4-inch resin side plate. My first thought was they contained a coil intended to balance out the presence of the large mass of metal present with the tuning gear drive next to it. Last night, however, I discovered these cylinders are not hollow. The ends of the two I have available to study finally revealed they are a tight roll of resin impregnated fabric. It is still possible that a very fine weave of non-ferrous mesh, or foil, is wrapped up within the coils of fabric, and these cylinders are serving some form of electronic purpose. A new ‘longshot’ idea is these cylinders are nothing more than a spacer, or guard, to protect the tuning gear drive from getting knocked out of alignment when the coil assembly is removed from its wooden case. I say ‘longshot’ because a 2-inch piece of 3/4-inch wooden dowel would have been a far cheaper and simpler solution for this type of problem. Adding to this mystery is the complete lack of reference anywhere in the 52-Set documentation to these resin cylinders. David Last edited by David Dunlop; 30-09-24 at 10:15. |
#1100
|
||||
|
||||
Quote:
__________________
1940 cab 11 C8 1940 Morris-Commercial PU 1941 Morris-Commercial CS8 1940 Chev. 15cwt GS Van ( Aust.) 1942-45 Jeep salad Last edited by Mike Kelly; 30-09-24 at 03:19. |
#1101
|
|||
|
|||
Hello Mike.
The frame work is actually 1/4-inch phenolic plates, assembled at the factory with zinc, or cadmium plated, brass brackets and hardware, another part of the design showing CMCs desire to avoid the presence of ferrous metal in the construction of these Coils, Aerial Tuning No. 2 A, at great length. They seem to have not wanted any latent magnetism developing within these units at all costs, and I fear I am not yet wise enough to understand why. Insert “Sigh” here. David |
#1102
|
|||
|
|||
COIL, Aerial Tuning No. 2 A. ZA/CAN 4725
I have pulled this photo up again because it shows really well the four sets of components that are fitted to the wooden case for the coil, once the coil assembly itself has been removed. In order to refinish the wooden case, all four of these sets need to be removed. These components are as follows:
1) Aerial Output Terminal - located on the upper left rear side panel. The tip of the socket assembly for it is just visible in the upper left corner of the photo. 2) Input Terminals - there are two of these fitted with wing nuts located one on each lower rear side panel. The inner brown phenolic mounting strips are clearly visible inside the back of the case. 3) Panel Mounting Brackets - three each across the upper and lower front of the case. 4) Case Mounting Plates - mounted to the bottom of the case, one each side. It should be noted, that with the exception of the casual mention of the two above terminals in the Operators Manual, none of these IDs are official and none of these parts can be found in either Issue 1 or Issue 2 of the Parts Lists for the 52-Set. Some of the individual parts making up these items are listed, however, but not all. I guess I should also point out here that I recently ran across a few pages from an Issue 3 of the Parts lists, dated 2 January 1953. I have no idea at this point if this was a few random page updates, or another full revision. I shall cover the removal and descriptions of these four components in the next four posts. David |
#1103
|
|||
|
|||
COIL, Aerial Tuning No. 2 A. ZA/CAN 4725
The first component I decided to remove from the coil case once the coil assembly had been removed was the Aerial Terminal. Not because it is in the way of anything else to be removed, but for the simple reason it is the most fragile component, which sticks out too much. The two main pieces of it are also in the realm of Unobtanium should they be broken.
This item is not referenced at all in the Parts lists as a complete assembly at all, but three components of it are, as follows: 1) INSULATORS, Ceramic, Bushing, Female ZA/CAN 4596 2) INSULATORS, Ceramic, Bushing, Male ZA/CAN 4661 3) SOCKETS, Antenna, w/sleeve, No. C1 ZA/CAN 4593 The last component is cadmium plated, 1/2-inch brass hex rod, fitted on its outer end with the cadmium plated brass socket with sleeve. The inner facing end is fitted with a 10-32 x 2.75-inch cadmium plated brass rod. A pair of .020 inch thick brown phenolic gaskets fit between the insulators and the wooden case, one each side. These were custom made for the application. I found both of these gaskets had become glued to the NATO Green paint since 1966 which was a little concerning. I found bt using a 4-inch steel putty knife at very shallow angle, the paint was thick enough I could slowly press into it to get the blade below the gasket and slowly lift it. As the gasket slowly came up, I gradually advanced the blade until the entire gasket popped free. This worked for both the inside and outside gaskets. These three pieces are clamped to the left side of the wooden coil case with a 1/2-inch OD 10-32 plated brass flat washer, plated brass 10-32 Shakeproof washer (internal tooth lock washer) and a plated brass 10-32 hex nut. When the connection is made to the internal feed from the tuning coil assembly, a 7/16-inch OD 10-32 plated brass flat washer is slide down against the hex nut already in place, the feeder cable fitted and then a second 10-32 Shakeproof washer and hex nut added to secure the connection. I am missing the second Shakeproof washer but have a few extras in my parts supply for when reassembly takes place. David |
#1104
|
|||
|
|||
This arrived today from Amazon.
When I discovered I was dealing with an aluminum plate for the front panel of the Coil, Aerial Tuning No. 2 A, I realized I had not had any aluminum primer on hand since I worked on my WIRE-5 project back in the 1970's. Back then, the 'Go To' primer for aluminum was the green Zinc Chromate stuff used in the aviation industry and I was able to source cans of it from Perimeter Aviation here in town. I was not at all surprised to discover the price of this stuff has gone through the roof since the 70's. When checking for alternate products on the web, this product came up and caught my eye because it is a white primer, not the old green I had used years ago. When I was restoring the various cast zinc knobs and handles on the rest of the 52-set a few years ago, I had to find a correct primer for working with zinc or galvanized items and the product I found was also white. So I will be using the same process for the front panel of the tuning coil. A first coat of the white aluminum primer. let is cure and give it a coat of standard grey primer and then the top coat. Just a can of xylene to track down now and I will be good to go for spray painting down the road. David |
#1105
|
|||
|
|||
COIL, Aerial Tuning No. 2 A. ZA/CAN 4725
The six Front Panel Mounting Brackets are another undocumented item in the Parts lists for the 52-Set. They are made from 1/8-inch thick by 1/2-inch wide, cadmium plated brass bar stock, cut into 1.5-inch lengths. These are them formed to create a 1-inch long bar with a 1/2-inch tab folded at 90 degrees at one end. Centred along the one inch base are two 11/64-inch holes, themselves centred 7/16-inches apart. The small tab is centre drilled and tapped to accept the cadmium plated RH slotted brass 8-32 x 3/8-inch panel mounting screw.
All six Front Panel Mounting Brackets are identical in their mounting to the wooden coil case with a pair of cadmium plated, 6-32 x 3/4-inch RH slotted brass machine screws, brass Shakeproof washers and brass hex nuts. If your Coil, Aerial Tuning No. 2 A has never been overhauled, or rebuilt, you will find once all the brackets had been installed, the hex nuts were secured with a dab of red lacquer. The one slight exception to the mounting process is found with the bracket in the lower front right corner of the coil case. This bracket has an additional brass fitting attached to it as part of the grounding arrangement for the aluminium plate front panel of the completed tuning coil. This fitting will get some separate coverage later, but since one end of it is also connected to the special front end machine screw for the right side Mounting Plate, these Front Panel Mounting Brackets need to be removed now to gain access to the Mounting Plate hardware later. David |
#1106
|
||||
|
||||
David, Xylene is available at Princess Auto for $14.99. I just got some there.
Barry
__________________
Every twenty minute job is one broken bolt away from a three day ordeal. |
#1107
|
|||
|
|||
COIL, Aerial Tuning No. 2 A. ZA/CAN 4725
At first glance, the two Input Terminals on the Coil, Aerial Tuning No. 2 A appear to be the most basic of parts. Then, when you get your first good closeup look, they suddenly turn into one of the most fascinating assemblies in the entire 52-Set.
These two Input Terminals are located on the lower rear corners of each side of the coil case, directly above the rearmost mounting screws for the two brass Mounting Plates located on the bottom of the coil case. As such, they need to be removed before the two Mounting Plates can come off the case. On the inside of the coil case, you can see the brown phenolic resin plates securing the two Input Terminal assemblies to the sides of the case. These plates are 3/16-inch thick, 1-7/8 inches long and 3/4-inches wide. they are held in place by an upper and lower set of cadmium plated, RH slotted brass 8-32 x 3/4-inch machine screws, brass Shakeproof washers and brass hex nuts. As a first step, DO NOT attempt to undo this hardware and remove the plate assembly. In designing the 52-Set, Canadian Marconi Company was concerned the Operators, under less than ideal conditions, could lose critical hardware, like wing nuts and lock knobs. They used two techniques to avoid such losses. One was to drill the tips of screws, mount the wing nut, or knob, and then fit a wire D-Ring through the hole to secure the hardware from loss. The other technique, as they employed here, was to fit the wing nut and then use a small punch and hammer to mushroom the tip of the screw slightly to prevent the wing nut from coming off. So neither the wing nut, or small mounting panel, will through the hole in the side of the coil case. However, if you first remove the hardware from the central terminal stud on the inside, things will become possible. From the outer end of the stud to the phenolic panel, there should be the folllowing plated brass hardware: 1) 10-32 hex nut 2) Shakeproof washer 3) 10-32 hex nut 4) Shakeproof washer 5) 10-32 flat washer. With all this hardware removed, and with good lighting, you will notice a 1/4-inch ‘square nut’ in the middle of the panel. if you apply pressure with a thumb to the exposed stud in front of this ‘square nut’, while at the same time gently pulling and rocking the terminal on the outside of the case, this stud assembly will pop free of the phenolic panel. You can then undo the hardware securing the panel and remove it from the coil case. Interestingly, this terminal stud is the only part of these Input Terminals toi get mention in the Parts Lists for the 52-Set. They are machined from 1/4-inch square brass bar stock and are identified as: STUDS, Brass, Special, ANF 10-32, 1-21/32 inches long, No. C1. ZA/CAN 8048 The finished item was cadmium, or zinc plated, and there is enough information in the description in the Parts Lists that a decent machine shop should be able to replicate them today. With the two Input Terminals safely removed from the coil case, the only components left to remove are the two Mounting Plates on the bottom of the case. David |
#1108
|
|||
|
|||
Hello Barry.
Thanks so much for the tip. It is the exact same product as I found here at RONA for six dollars more. I shall be launching a Princess expedition shortly, but I must say, I do miss the ones when their yard was full of rows of half tracks, CMP's and WIRE-5 boxes, and mind boggling other bits. David |
#1109
|
|||
|
|||
COIL, Aerial Tuning No. 2 A. ZA/CAN 4725
The last set of components to be removed from the coil case are the two brass Mounting Plates on either side of the case bottom, that support the four Airloc Studs which are used to attach the Coil, Aerial Tuning No. 2 A to either the top, or right side of the Carriers No. 4 for the 52-Set.
Each of these plated brass Mounting Plates are fastened to the coil box by three plated brass 10-32 RH slotted machine screws. On the left hand side, these three screws are all one inch in length, with matching plated brass Shakeproof washers and hex nuts. On the right side Mounting Plate, the same one inch long hardware sets are used for the back and centre positions. In the front position on this side, a plated brass 10-32 x 1-1/4 inch RH, slotted machine screw is used. The extra length is to allow for the fitting of the brass grounding strap connected to the aluminum front panel of the coil assembly. But the hardware for these plates does not end there. Each of the six mounting holes is 3/16-inch diameter and passes through the 3/8-inch pine board bottom of the case, as well as the 1/2-inch square pine strip reinforcement found mounted in the corners of the case. From the inside, a 13/32-inch diameter countersunk hole has been drilled down into each hole 3/16-inch deep. In the bottom of each hole, in both tuning cases I have available, I have found a plated brass 10-32 flat washer with a 3/8-inch OD. These are needed to prevent crushing of the wood when the Mounting Plate hardware is installed. The countersunk holes appear to have been factory painted and I am not sure if these washers were originally fitted with dab of glue, or have simply stuck to the painted surfaces of the holes after 80 years of close contact, but not one of them was willing to fall out on its own. Each had to be carefully popped out with a thin awl. Getting this hardware out to remove the two Mounting Plates is challenging. When the hex nuts were originally fitted, they end up just below the surface of the wood in the countersunk holes, so are inaccessible by means of a spanner or 1/4-drive socket set. This took a bit of thinking on my part to solve. Ideally, to keep the hex nuts from rotating with a potentially sticky screw, the hex nut needs to be held in place directly. I was hoping my various parts bins might have held an old bicycle tyre inner tube from which I could punch out a nickel sized disc of rubber. No such luck. But I did find a scrap piece of canvas from which I cut a one inch square pad. I then wet it just to the point of being slightly damp. With a little experimenting, I found that the 1/4-inch socket in my quarter drive set was the perfect size to fit freely inside the countersunk holes in the wood, while also fitting freely over the tip of the machine screw. By placing the damp bit of canvas over the hardware, I could then fit the quarter drive setup on top so the rim of the socket was resting fully on the face of the hex nut. I did this with the coil case resting on one side at the end on my bench just far enough the Mounting Plate assembly cleared the bench and the side of the coil case was flat on the surface of the bench. In this way, with pressure applied to the faces of the hex nuts, all the three sets of hardware on the left side Mounting Plate, and the back two sets on the right side, all came apart easily. The front screw set on the right side Mounting Plate is the 1-1/4 inch machine screw that has the additional Shakeproof washer and hex nut set holding the brass grounding strap for the front panel in place. With this first hex nut/washer set removed by conventional means, the brass ground strap can be removed to expose the recessed second hex nut and lock washer. The 1/4-inch socket was deep enough that with the canvas snugged down on the part of the hex nut facing into the coil case, this set of hardware also came off easily. The coil case now sits free of all its fittings, except for the green felt pad glued to the bottom. My apologies that this post turned into such a ‘Natter’. David Last edited by David Dunlop; 13-10-24 at 04:22. |
#1110
|
|||
|
|||
Coil, Aerial Tuning No. 2 A Front Panel Grounding Strap
This is another unrecorded 52-Set item in the Parts Lists, so I thought it should be documented here as much as possible, in case somebody ever needs to fabricate a replacement.
It is made from 0.035 inch thick brass sheet and has been plated with zinc, or cadmium, upon completion. The basic form is an L-Shape, punched from the brass sheet. The main body is 3/8-inch wide and 1-9/16 inches long. The foot of the “L” is also 3/8-inch wide and 13/16-inch long. At the inside junction of the “L”, a 1/16-inch wide notch has been punched 3/16-inch into the main body. This has been done to allow the outer 1/2-inch of the foot to be bent upright 90 degrees at a very sharp angle, without tearing or warping the brass sheet. The hole in the base is 3/16-inch in diameter, centred 1/4-inch from the end. The hole in the foot tab is 5/32-inch in diameter, centred 3/16-inch from the end of the tab. The first photo shows this grounding strap sitting as it does when fitted into the coil case. The second photo is the ground strap simply tipped over onto the foot tab. David |
Thread Tools | |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
Canadian staff car wireless: World War 2 Canadian R103 Receiver Demo | Mike Kelly | The Wireless Forum | 5 | 24-07-16 16:20 |
Found: CMP Wireless body project | Jim Burrill | For Sale Or Wanted | 7 | 05-04-15 01:02 |
Canadian dehavilland mosquito restoration project | David Dunlop | WW2 Military History & Equipment | 9 | 10-07-14 01:51 |
Canadian project | David Ellery | The Carrier Forum | 9 | 28-04-07 02:36 |
FOR SALE/TRADE: 1944 CHOREHORSE PROJECT for Signal Corps Wireless Power Unit Project | Alain | For Sale Or Wanted | 1 | 21-02-07 01:11 |