Wireless Set No. 52 Canadian - Project

[David Dunlop]

This package arrived in the afternoon Post today.

I decided to go with the Hayes Paper product after some lengthy web reading as this company was consistently in the top section of all reviews, their own website has a very good section on how to best use this product, including the pros and cons of various sealers and relaxing agents used to get q good fit of the decal over raised surface details.

Eventually, I am going to have to completely refinish the front panel of the main set Supply Unit, which will include a full new set of decals. Now when the time comes, I can roll right into it without worrying about being able to source the necessary bits and pieces.

David

[David Dunlop]

This morning I was able to remove all the loose switches from the front of the chassis. I did not want them continuing to swing and bang about while maneuvering the chassis around trying to work on the removal of other bits.

I can see already I will be needing more desoldering wick real soon.

Once the removed parts are cleaned and checked, I bag them with an ID Sticky Note and if the part is compatible with any Canadian 19-Set Mk III parts, I make note of that as well. It slows things down a bit but at least in the future, I will know exactly what I am looking at during a parts search.

I will start on one of the Tag Panels at the back of the chassis next.

David

[David Dunlop]

I was in the mood, and had the time, to remove one of the Tag Boards from the rear of the parts receiver chassis this morning. If any of you are familiar with Allan Isaac’s restoration work in England on the 52-Set receiver, this is referred to as the ‘ER Tag Board, and was located in the empty section of chassis in the lower right section of this photograph, below the V2B socket, where the two small mounting posts are now visible. If you refer back to Photo 1 in Post #580, you can see this board as originally mounted on the chassis of a receiver.

The work went rather well with just a pair of needle nose pliers and the soldering iron to remove the relevant leads.

A screwdriver was then needed to remove one grounding strap and the two mounting screws for the board.

David

[David Dunlop]

After a careful search of the Master Parts List for the 52-Set, this turns out to be the official part name for the Tag Board ER in my previous post.

The two attached photos show this Panels, Phenolic now free of the receiver chassis. The three pieces of masking tape on the rear of the panel are simply an orientation reference for the panel should I not see it again for several months, and to hold the mounting hardware in place.

For some reason, when I first turned the panel over, I was surprised to see the wire lead in place across the top of the panel. Then it slowly sank in that all such panels in the 52-Set would have been stand alone, sub-assemblies during the manufacturing process. Components would have been fitted to the various panels as appropriate and then these completed panels would have arrived at various stations on the assembly line to be wired and mounted onto the appropriate chassis assemblies.

If you look closely at the rear view photo, you can see where the two capacitors were mounted to the panel at the second pair of tags from the left and the last pair at the right end. The capacitor leads were fed down through the tag panel holes, and then wrapped back up around the edge of the panel and back around the upper ‘T’ terminal of the tag. An interesting approach, as this would have physically held the capacitor firmly in place and allowed the station operator a free hand in soldering the capacitor in place.

The other interesting thing I noticed is the offset mounting holes. This allows the panel to be mounted on the chassis, one way only, further reducing the risk of errors on the assembly line.

On the front side of the panel, where the unoccupied tags are seen, you can see a black, circular C.M.C. Inspection Stamp, and below it a small blob of blue paint. I have seen this blue paint blob referred to in other CMC documentation as proof that a particular component works to required specifications, so I am guessing the black inspection stamp simply confirms the panel was properly assembled.

While I think of it, does anyone know if there is a standard, or accepted way of numbering the tags on one of these panels? They all seem to be referenced by the number of terminal tags present and these are always in even numbers. The even numbers makes sense, but where and how does the numbering typically run?


David

[Mike K]

They are unusually small resistors for use in a valve set.

[David Dunlop]

Good Evening, Mike.

Don’t let the 52-Set Receiver fool you. It, along with its related Crystal Calibrator and the two Vibrator Supplies used to power it (the ZE-11/12 Remote and the Vibrator Section of the Main Supply Unit) are definitely the low voltage demand parts of the 52-Set. Those little ¼-watt resisters work very well there.

There are a total of 130 resisters used throughout the 52-Set. Of those, 66 are ¼-watt rated, and of them, 49 show up in the receiver circuits. The rest are in the Sender.

Next step up is the ½-watt rated resisters, and at that point a dramatic shift is already taking place. There are 31 ½-watt rated resisters in the entire 52-Set. At this point though, only 8 are in the receiver circuits and the other 23 are in the Sender.

The balance of the resisters fall between 1 and 50 watts rating and with a handful of exceptions all are found in the Sender and its related twin dynamotor supply. With those components you are in the realm of 1,000 to 10,000 volts to control.

Best regards,

David

[David Dunlop]

This important little relay was missed in both wartime editions of the Master parts List for the Wireless Set No. 52, but was finally picked up in the postwar 1948 edition.

It shares the rectangular mounting plate for the Connectors, 7-Pin PL1A on the upper left rear corner of the receiver chassis. It is mounted on the inside face of the plate in question.

The importance of this relay is that it disconnects the receiver from the aerial circuits whenever the set goes into either Send or Break-In Mode to protect the receiver. It's circuit reference number is 'S5A'.

I am not certain who the manufacturer was, as the first word of the name is a little hard to read, but their part number shows up quite nicely, below the name.

David