Wireless Set No. 52 Canadian - Project

[David Dunlop]

Lately, in the time spent stepping away from the resistance analysis of the Sender, in order to clear my head, I have been thinking about the reasoning behind the Canadian Marconi Company changing the name of the piece of canvas they designed to provide some degree of moisture protection to the front of the 52-Set.

When you first look at it, everything makes sense. It rolls up and down in front of the Set, just like a ‘curtain’ in a window. It is waterproof, but absolutely not weatherproof. If the operator was caught outdoors in the rain working a 52-Set, I would not want to be that operator. In the rain, nothing about a 52-Set would be ‘covered’ with this simple piece of canvas.

Why Marconi chose a light olive green canvas for their curtain, may simply have been a factor of product availability at the time they needed to get the curtain into production. Khaki Tan may just not have been available. Nothing about any of this appears to be sloppy work on the part of CMC. They clearly knew it would be unwise to operate a 52-Set exposed in wet weather. If it was not going to be installed in a fixed building, or an enclosed vehicle, CMC went to the trouble of ensuring a Wireless Tent Kit was available to operate the 52-Set. Marconi had covered all the bases.

Photo evidence suggests the first curtains that used nickel plated hardware was a bad idea that Marconi identified and fixed, switching to matt black hardware in production as soon as possible. To date, no 52-Set components have turned up bearing 1945 dated data plates, so if seems logical production of the 52-Set ended a some point late in 1944. This would have included full sets, kits and a appropriate amount of spare parts. However, the February 1945 Master Parts List identifies this canvas item as “COVERS, Waterproof No. C2” but advises items may be found identified as ‘curtains’ and this is to be ignored. Identical information is found in the July 1948 revision of the List. It seems likely, therefore, the identification of ‘COVERS, Waterproof No. C2’ is a pure piece of supply system paperwork, simply for standardization purposes. It is highly likely, items were never manufactured bearing this identification.

I took a look in my 19-Set Parts Lists and found the following five covers:

COVERS, Waterproof No. 1 ZA 2952 for Carriers No. 21
COVERS, Waterproof No. C1 ZA/CAN 1076 in Universal Carrier
COVERS, Waterproof No. 5 ZA 10317 for Carriers No. 23
COVERS, Waterproof No. 16 ZA 10411 for Variometer
COVERS, Waterproof ZA/CAN 1362 for 19-Set Cdn in Carrier Universal


So in spite of the fact the 52-Set ‘CURTAIN, Waterproof’ is indeed a ‘curtain’ and does not cover the set at all, as any of the above noted items would, bureaucrats decided the name must change, not Canadian Marconi.

The three attached photos are of the following COVERS in my collection: No. 1, No. 5 and No. 16.


David

[Chris Suslowicz]

Originally Posted by David Dunlop

I took a look in my 19-Set Parts Lists and found the following five covers:

COVERS, Waterproof No. 1 ZA 2952 for Carriers No. 21
COVERS, Waterproof No. C1 ZA/CAN 1076 in Universal Carrier
COVERS, Waterproof No. 5 ZA 10317 for Carriers No. 23
COVERS, Waterproof No. 16 ZA 10411 for Variometer
COVERS, Waterproof ZA/CAN 1362 for 19-Set Cdn in Carrier Universal

The three attached photos are of the following COVERS in my collection: No. 1, No. 5 and No. 16.

David

I can add Cover, Waterproof, No.7 which is for Carrier No.25 with the top plate fitted (this carries the Variometer, Aerial Base, and Control Unit).

This has two exit holes for an aerial rod (with Grommet No.23 and a blanking grommet so that the aerial base can be in either position), large holes with water protection flaps on both ends and at the rear, to allow for cabling to other control units - they will pass a 12-pt connector, etc. It's a complicated bit of canvas. (The stitching is going on mine, and I need to get it repaired.)

Chris.

[Bruce MacMillan]

Here's some more info the the WS52 from the Canadiana site. Also lots of other wireless stuff.
https://heritage.canadiana.ca/view/o...eel_c5817/1341

[David Dunlop]

Thanks for posting that link, Bruce.

Looks like I will be able to do some more research reading this weekend.


David

[David Dunlop]

Earlier this evening, I finally found the last component I needed to investigate related to the abnormal test results I was getting for the V1J Speech Amp circuits in the Sender.

The component was resistor R49A, related to the V1J Plate Load and I had to remove the T2A Transformer, once again, from the rear skirt of the Sender chassis to reveal its location. I had suspected it was hiding back there at the very start of this quest, and had actually looked with a small, flexible mirror behind T2A, to no avail, so I went on to track down all the ‘easy’ stuff first. More on that later.

In any event, to save anyone else hunting for this resistor down the road, here is a photo of what it looks like and where it hides. It is rated at 100 KOhms, with a +/- 20% tolerance at 1/2-Watt. This one tests out at 126.4 KOhms, so is now on my “To Be Replaced” List.


David

[David Dunlop]

All of the required resistors have now been tested and I have just started looking into the capacitors. To complete that portion, I will need to remove the circuit board mounted on the rear chassis skirt, shown in the second photo in Post #949, and I will have to study that setup a bit first, before removing the three mounting screws holding it in place.

I also discovered that it is possible to carefully spin the cardboard sleeves on those four capacitors around their metal cores, so I was able to wipe all the dust and dirt off them all and expose the sides showing their PC-Numbers and Stats. In addition, as Chris had suggested, I was able to ID two of these capacitors by cross reference to the 19-Set Documentation. So now all four of them are identified

I will sort the resistor results shortly and post them


David

[David Dunlop]

Here are the 10 Resistors in the V1J and V5D Circuits I have been looking into. The data is in order of Circuit Reference, Rating, Tolerance, Circuit and Test Result.

R12A, 250-1/2, 20, T2A Primary Feedback Voltage Div, Tested 8 Ohms *
R16A, 400-1, 20, V5D Cathode Bias, Tested 560 Ohms *
R27D, 5,000-1/4, 20, V1J Cathode Bias, Tested 5,480 Ohms *
R31D, 10,000-1/4, 20, T3A Tertiary Feedback Voltage Div, Tested 8 Ohms *
R37A, 10,000-20, 20, V5A Screen Voltage Dropping, Tested 10,000 Ohms
R41B, 20,000-1/2, 20, V1J Plate Decoupling, Tested 23,070 Ohms *
R46A, 40,000-1, 15, V5D Screen Voltage Dropping, Tested 40,000 Ohms
R49A, 100,000-1/2, 20, V1J Plate Load, Tested 126,400 Ohms *
R56E, 500,000-1/4, 15, V1J Screen Decoupling, Tested 590,000 Ohms *
R61A, 1 Meg-1/4, 20, V5D Grid Leak, Tested 1.178 Meg Ohms *


* To be sourced for replacement.

And the Saga continues.


David