Wireless Set No. 52 Canadian - Project

[Chris Suslowicz]

Originally Posted by David Dunlop

This part of the project is a ‘Planning Ahead’ segment, more than anything.

I will eventually be doing a restoration of the Supply Unit for my 52-Set, which is going to bring the two dynamotors into the picture. The main concerns with them will be the inspection and cleaning of the brushes and armatures, which is a relatively straightforward process. Where it will get interesting, however, is the cleaning and regreasing of the bearings.

This 52-Set was very likely last operated sometime in the 1970’s, and when the dynamotor bearings were last cleaned and lubricated prior to that is anyone’s guess.

Version 2 of the Parts Listings for the 52-Set, issued July 1948, identifies the grease used as GREASE, Lubricating, Andoc and it was available in 1-pound tins.

In 1954, Modification Order No. 4 was issued dealing with changing the original grease to one identified as 3-GP-683a, which was an Arctic tolerant grease, if the 52-Sets were being deployed there.

While checking the web today, it appears Andoc grease was an Exxon Product and version ‘Andoc C’ was discontinued in 2001. I have no idea what the qualities of this particular grease were, to be able to match it to a modern substitute, so I am very much open to suggestions for an appropriate substitute. I would like to track down suitable grease ahead of time, rather than have the project grind to a halt, when it reaches the point of restoring the Supply Unit.

David

Searching for Andoc C Grease in Google, got me a "Table 14a List of Consumable Material" and Item 55 is "Grease, ball and roller bearing" Specification "Commercial, Standard Oil ANDOC C" in 8oz. tubes, FSC 9G9150-261-8311, intended use "Lubricating bearings for high speed and temperature", which sounds about right.

https://www.nationalprecision.com/mi...lubricants.php suggests "Polyrex EM" as a replacement for Andoc C, though it looks like Beacon 325 or Royco 27 might be good substitutes depending on temperature range.

The last two are Lithium grease variants, and with any change of lubricant type it's very important to get rid of any existing grease before re-filling the bearing (to avoid chemical reactions between different grease types that can -under some circumstances- produce a compound of abrasive rather than lubricating properties).

I think these are aerospace/military lubricants and therefore Not Cheap. Any standard grease for small motor bearings should be fine.

(I made the mistake of looking up Royco 27 on Amazon and the first hit was "Royco Mchuzi Mix (Spicy Beef Flavour)" which to my mind has dubious lubricating properties and is unlikely to be suitable for this application.)

Chris.

[David Dunlop]

I have not reported much on this project recently, so thought an explanation would be in order. I have been sidetracked with a related project(s).

I am at a point now where I need to go through both receivers to align and calibrate them. This requires a multimeter and an oscilloscope. I have a good analog and digital pair of meters to do part of the work with, and I had a working OS8-B Oscilloscope until last October, when a pair of electrolytic can capacitors in the power supply died. Exact modern replacements are available but pricy.

In November, a local friend told me of a pile of surplus electronics that had just been dropped off at a local museum and that most of it was not usable for the museum and headed for scrap. He suggested I drop by for a rummage. Ended up coming home with four semi scrapped Tektronix oscilloscopes and a pile of related goodies. The scopes weighed 65 pounds each and it took two car trips to get all the stuff home. All for the price of a large Timmies Coffee.

Out of the four scopes, I now have one restored and finally doing almost all it is supposed to do. Still a bit of fine tuning to sort out, but the end of this project is finally in sight. Then I can get back to the two 52-Set receivers and get them finished.

David

[David Dunlop]

Thanks for the information on the grease, Chris. You are right...best not mix it up with the spices.


David

[David Dunlop]

I had to take a break from oscilloscope work this week as my head was starting to spin, and I think I was also developing a mild case of 52-Set Withdrawal.

I decided to try a little more hand polishing to remove more of the yellowed varnish top coat on the Sender panel. A simple half hour of freehand work without work lights. I tackled the lower right quadrant of the sender fan door assembly, where I had earlier removed a set of red numbers. (See Posts 201 and 228).

The polish cloth was coming away with quite a brown tone to it as I worked, but the colour did lighten up quite a bit and when the time comes to clean the Sender panel, I think I should be able to get a very close match to the upper portion of the Receiver panel.

The other little bit of excitement was the arrival yesterday of a second Cases, Spares Box for the 52-Set.The interior KimPaK lining in this one is as close to mint as one could hope for, compared to my other box. (See last photo Post 168). Restoring/replacing that lining was going to be a major challenge, so I was pleased to cross paths with this one.

This box also underwent a NATO conversion on the outside and I will be surprised if any original stencil markings show up. But I will take a careful look...just in case. The exterior of the box was sanded and NATO Greened, and then a large patch of tan paint was slapped on and NATO stencil ID's added in black. It looked so garish, the previous owner toned it down with a uniform coat of green paint.

David

[David Dunlop]

This assembly is missing from the Slow Motion Drive on my Sender P.A. Drive Dial. I have been able to source an example of the earlier version from a 19-Set Mk II, which I can install to get the dial controls operational, but I would eventually like to find the correct later version of this assembly.

The early (Mk II 19-Set) version is a single leaf spring item. With hard use, these were found to weaken over time so on the 19-Set Mk III Canadian, and the 52-Set, a reinforced version of the assembly was introduced. It can be recognized by the addition of a second half leaf piece of spring steel riveted at the base end pivot point.

If anyone happens to have a junker Mk III Canadian 19-Set with one of these reinforced assemblies available, please let me know.

David

[David Dunlop]

The oscilloscope sub-project is now officially on the back burner. I have been able to bring it back from a disassembled hulk to a working scope, even if, at the moment ‘working’ is not yet exactly as per design.

Having been away from the 52-Set Project for almost two months is enough time away. I pulled out the 2nd to 4th Echelon Repair Manual and started rereading it today. With a little luck, I should be able to align and calibrate both receivers, without having to sort anything serious out with a scope.

I do like the approach of the individuals who wrote the repair manual. They start you off nice an simple. Step 1 is to zero the indicator needle on the meter and calibrate the meter. So off we go! I will continue to post as things unfold.

David

[David Dunlop]

Well I am finally catching up a bit on this project, but not without a fair amount of multi-tasking. Something I have never been very good at for long, without getting a major headache in the process and a large empty space in the wine cellar (for which I deny any correlation whatsoever).

The first thing I realized was the documentation of work in the 2nd to 4th Echelon Work Manual is comprehensive, but not organized in the best manner for actually recording test data results. Five tables of specifications relate directly to the 52-Set Receiver as follows:

Table 7 - Receiver Voltage Check
Table 8 - Receiver Resistance Chart A
Table 9 – Receiver Resistance Chart B
Table 10 – Crystal Calibrator Resistance Chart A
Table 11 – Crystal Calibrator Resistance Chart B

I have now transcribed the first three tables to Excel Spreadsheet format, adding in spaces for recording actual test results next to each specification. This makes saving the data for later analysis so much more efficient. I hope to have the two calibrator tables finished by next weekend.

In addition, this morning I was able to complete working through the data collection from my Remote Receiver for Table 7. This data is collected with all valves and lamps in their sockets and the chassis powered up. It took longer than I thought, for a couple of reasons.

First issue to arise, was realizing I had been away from working on my 52-Set just long enough to not remember the pin layouts of all the valve sockets, when viewed from the top, or bottom, of the sockets, and once I had sorted Pin 1 locations out, whether the pin count proceeded from that point in a clockwise or counter clockwise fashion. It took about four sockets before it all started to come back to me.

Since all valves are in place and the power is on, the only place to access the socket pins is from below the chassis. That seemed pretty good initially, as all valves except V1G and V1H can be accessed at the back of the chassis. The remaining two can be reached simply by tipping the chassis to either side to expose the bottom chassis assembly. But there is always and exception, isn’t there…and in this case it was two!

V1A and V1B sit quietly in the upper right rear corner of the chassis, directly behind the large Bakelite 8-pin Connector Socket. There is no way around it. The three small screws holding the connector backing plate to the upper right rear corner of the chassis have to be carefully removed and the Connector Socket assembly guided gently away to expose the two valve sockets beneath it.

That’s when the second issue surfaced. Once I was satisfied the Connector Socket assembly was safely out of the way of the two valve sockets and no exposed contacts on the assembly were touching anything they should not be, I turned the Remote Supply Unit back on. No Pilot Lamp and no Low Tension showing on the meter. My first thought was I had broken one of the wires on the Connector Socket, so carefully checked them all. They were fine. Then I remembered, the ground for the socket is through its backing plate being mounted to the receiver chassis. A quick addition of a jumper cable between the chassis and the backing plate and on came the Pilot Lamp and 12 volts showed on the meter. Data collection from the Remote Receiver for Table 7 has now been completed.

David