Wireless Set No. 52 Canadian - Project

[David Dunlop]

This last set is of my WS No. 19 Mk III Cdn, all built in 1944, the same year as the Marconi 52-Set equipment. The Transceiver is RCA, the PSU is Northern Electric, the Crystal Calibrator is Marconi and the Pocket Watch is unmarked.

David

[David Dunlop]

A little bit more cleaning up work done on the Main Set Receiver this last week as I removed all valves with their related shields and caps and gave everything a good cleaning to get all surface dirt and oils off of them. Three or four valves showed a slight bit of looseness between the glass envelope and the base plug assembly, but nothing alarming. To be expected with 75 year old putty I suppose.

Prior to cleaning the valves, I had warmed the receiver up and used the Meter to test the valves it was intended to and found no response for V1B and V1F. After cleaning and reassembly, I rechecked the two valves on the Meter. The first couple of times on each valve, nothing. On the third time moving the selector switch to each questionable valve, the Meter Indicator twitched. Fiddling the switch a bit resulted in excellent readings for both valves. Turns out the problem was oxidation buildup on the switch contacts and not the valves. I have a can of contact cleaner kicking about somewhere, but have had it in the shop for quite a few years now. Might be best to purchase a new can and toss the old one when I find it. But in the meantime, another little problem solved.

The Handles No. 72 and Screws, Clamping No. C2 on the Frequency Dial of the Main Set Receiver are very badly chipped and oxidized. On my backup receiver, these items are mint, so I have decided the next project will be to swap them out. This means digging out my overhaul manual for the WS No. 19 and refreshing my memory on the correct procedure as it has been a while since I last did that work and it involves a number of fiddly bits and correct sequences as I recall. Interestingly, the Drives, Capacitor, No. C1 used on the 52-Set is identical to the one used on the 19-Set, but the 52-Set Parts List notes that the Drives manufactured for the 52-Set were built to higher tolerances than those for the 19-Set.

David

[David Dunlop]

I had a set of these that came with some 19-Set bits years ago. The Mic was finished in wrinkle No. 2 Brown. Recently I came across another headgear assembly, along with a couple of other items, for sale. This set apparently had a Mic that was finished in wrinkle Olive Green, and I thought that would make an interesting pairing for the 52-Set Project.

The three items arrived in the Mail yesterday and what had looked like the correct green in the photos, turned out to be another NATO Green repaint. On the bright side, however, lots of chips in the paint reveal that the original colour was also wrinkle No. 2 Brown, so it all works out.

David

[David Dunlop]

Two of these items were issued with the Remote Receiver Kit and were stored in the wooden Remote receiver Operating Case.

I had one Receivers, Headgear still in a parts bin, which I think had been left over from a number of Wireless Remote Control Sets I had accumulated years ago.

A few weeks back I came across another one of these headgear, still in it's original factory box. I am not certain, but think that when the 52-Sets were originally issued, all of the kit stored in the various cases would have been in original packaging and the Wireless Operators would have unpacked what was needed and the rest would have stayed unopened until needed. So I think this item will work well, whenever I find the wooden case for the Remote Receiver. One headset will be ready for action and the other still in the box.

David

[David Dunlop]

The last items that arrived this week were a pair of these replacement receivers, also in their original packaging.

A pair of these were issued as spares in the 52-Set Spare Parts and Valves Box and they would have served as replacements for either of the two headgear items issued with the 52-Set.

Interestingly, both this package and the earlier noted Receivers, Headgear, MC Cdn Mk 1, in its original packaging, were held at one time (May 58 actually) in 25 Central Ordnance Depot, Montreal, Quebec. I would love to have had a tour of THAT facility in the late 1950's!

David

[David Dunlop]

I am pleased with the results of the British Valve Adapter project I have been working on recently. I am 100% certain the adapter itself will work as intended. Before putting it to the task of checking the valves in my 52-Set receivers, however, I realized that after many years of very casual use, it would be prudent to calibrate my Precision 612 Tube Tester to ensure it is in good working order. This is actually a fairly straight forward task, there being only one tube in the tester circuit (a 5Y3GT), one capacitor and about 10 easily accessible resisters to be checked.

‘Pop the tube out. Give it a quick test, and pop it back in or replace it.’ My Brain said, far too eagerly. It took a while for the concept of owning only one tube tester to take hold. So until I can team up with a mate with a tester on hand, I have headed back to the 52-Set work on my bench.

The slow strip down of the backup receiver is continuing as per the first photo. The tuning knob bits are all together waiting to be used to upgrade the Main Set Receiver.

I had commented a while back the tuning on the Main Set Receiver was alarmingly stiff. I suspect the shaft supports, front and/or rear, of the tuning condenser shaft itself are at fault. I am hoping the issue is with the front end as it is quite easy to access. The other two photos here show the tuning shaft exiting the rear of the Flick Assembly behind the front panel of the receiver and heading into the coil spring like flexible coupling. The last photo shows the tuning condenser shaft exiting the flexible coupling and disappearing into the front shaft support of the Tuning Condenser Assembly.

David

[David Dunlop]

With the successful completion of my British Valve Adapter Project, I have now switched my attention back to working on the 52-Set Receivers.

I have managed t do a little more strip down of the backup receiver, freeing up the knobs, handles and a number of brackets. I am making a concerted effort to properly tag each of the parts with their ID’s and ZA/CAN Numbers and bag them for storage for future use. Something I have not been prone to do in the past.

As you can see, the poor old girl is looking a lot more forlorn now than she did a few months ago.

One thing I thought would be worth mentioning here, as a perfect example of it can be seen to the left of the Power Indicator Lamp, where one of the round chassis handles was located. A large section of the panel paint has fallen away in pieces. It is not always possible to prevent this from happening with 75 year old paint, but some care can go a long way to help minimize this potential problem.

During the original assembly process, fittings and hardware were being installed on new paint, which, depending on delivery timings, could be anywhere from a few hours to a few days old. In many cases not fully cured and hardened. Consequently, it is not unusual for the added fittings and hardware to bond to the new paint after they are mounted and the hardware run home and the paint continues its curing process. 75 years later, and you need to remove said piece, there is a good chance the piece you are removing will stick to the panel paint and pull a piece off when removed.

The other problem is the likelihood of oxidation developing on the surface of the metal, underneath the paint, over time. Even though the oxidation layer may be very thin, it has no strength, that means the bond between the metal panel and the finish paint coat has been compromised, even though the paint may look minty new.

When removing hardware or parts from a painted panel, it is a good idea never to turn the fitting, or hardware on the panel face. Use a screwdriver , or socket to hold the part stationary and undo/unscrew the hardware on the backside of the panel. This will help minimize the risk of scales of paint coming off the panel.


David