Wireless Set No. 52 Canadian - Project

[David Dunlop]

This particular Tag Panel has been the most challenging to remove so far. It is mounted to the right side of the top rear section of the receiver chassis, on two small metal posts, riveted in place. The two left end capacitors on this Tag Panel are just visible in the upper left corner of the 4th photograph in Post #579.

This Tag Panel is an excellent example of the type of pre-wiring that went into these sub-components, prior to their installation on the receiver chassis on the main production line at Canadian Marconi.

You will notice on the backside of this Tag Panel, several interconnecting leads have been soldered into place, in addition to the mounting of the five capacitors and four resisters.

The brown, phenolic bar, riveted in place at either end on the rear of the Tag Panel, allows the panel to stand away from the receiver chassis plate enough to prevent the interconnecting leads and tag assemblies from making any contact at all with the metal chassis.

Probably not the most entertaining of things to read about regarding the 52-Set, but with the surviving supply of original documentation on the 52-Set what it is, I feel the more information that can be made available, for anyone else, the better, and sooner or later, it is bound to tie in with some other information somewhere else.

David

[Mike K]

Is that two layered insulation on the wires ? On a couple of the wires, I think I can can see a black covering, then a cotton layer over that black stuff. On other wires it is a plain PVC ? Quite a mix of insulation .

[David Dunlop]

Afternoon, Mike.

From the ends, up close, it is just a form of 1940’s ‘plastic’ sleeve. The jumpers are solid tinned copper leads and I think these black sleeves were just an added insurance against the leads shorting against the chassis behind the panel, as a possible result of any misadventure the receiver might be involved in.

They are slightly loose on the leads but for the most part do not move easily due to these leads having been drawn in rather close to the back of the panel when soldered in place.

So basically just the solid lead and the sleeve, Mike.

Best regards,

David

[Chris Suslowicz]

The trade name was "Systoflex" and was a varnished woven cotton tube. I think yellow was the most common, but other colours were produced.

There was also varnished cambric tape, "Empire Tape" and Empire Cloth used in cable insulation and transformer/coil manufacture.

Chris. (Yes, I'm a mine of useless information.)

[David Dunlop]

This Tag Panel is located in the upper left back corner of the receiver chassis. A full on view of it is available once again in Post #579, Photo 4. This photo also shows how the Tag Panel I removed yesterday (the two capacitors of which are just visible at the left of this photo) blocks access to this PANELS, Phenolic, 30-Tag. This Tag Panel was likely installed prior to the other one from yesterday being mounted.

Three mounting posts are used to fasten this Tag Panel in place. The holes are asymmetrical which means the panel can only be mounted in one position; the correct one. This Tag Panel holds five capacitors and eight resisters, along with six jumper wires. Interestingly, the jumpers on this PANELS are rather eclectic. Two have yellow sleeves, two black and two are standard traced leads.

In working with these PANELS, Phenolic, Tag lately, I have begun to make sense of the assembly process. Resistors were mounted first. Then the oil and paper capacitors were installed, often with the preinstalled resisters trapped between pairs of capacitors. Next, other capacitors followed by the jumper leads and lastly any single leads that would be soldered to other components on the chassis at a later point in assembly. These single leads are the ones I have left in place on the Tag Panels, unsoldering them at the other components, where they are usually more accessible.

I suspect that once these Tag Panels were installed, the connections to the major laced harness assemblies would be completed. These harnesses could either be pre-existing in the chassis at the time the Tag Panels were installed, or installed themselves at a later point.


David

[David Dunlop]

Hi Chris.

Good timing. The yellow version has now made itself evident.

Thanks for the explanation.

David

[Chris Suslowicz]

Originally Posted by David Dunlop

Afternoon, Mike.

From the ends, up close, it is just a form of 1940’s ‘plastic’ sleeve. The jumpers are solid tinned copper leads and I think these black sleeves were just an added insurance against the leads shorting against the chassis behind the panel, as a possible result of any misadventure the receiver might be involved in.

They are slightly loose on the leads but for the most part do not move easily due to these leads having been drawn in rather close to the back of the panel when soldered in place.

So basically just the solid lead and the sleeve, Mike.

Best regards,

David

It's also a lot more efficient for the assembly line workers: no tedious stripping of insulation (with the risk of nicking the conductor and creating a weak spot). Just a spool of tinned copper wire, a pair of sidecutters, and a tray of pre-cut sleeving (or a reel and pair of scissors, but pre-cut is faster).

Feed the wire through the first tag, slip the sleeving on, feed the end through the second tag, wind the end round the second tag, (snip end if necessary), pull wire taut and wind around first tag, then cut it and move on to the next pair of tags, Soldering would be the last step, possibly by a different operator.

Because it's all rigidly fixed (and I'm sure we've all cursed the construction method employed when trying to remove components fitted like this), it can be inspected before soldering and any mis-wiring rectified, then tested after soldering.

Wiring looms would be built on a board with nails/pegs or clips to hold the end of each lead, marked for wiring colour, and laced on the board ready for installation.

(I don't know if you've ever considered the WS19 control boxes, but they must have been built in the open, probably in a jig to hold the switches and connectors in the correct position, before being folded into the right shape and fitted to the outer shell of the box.)

Best regards,
Chris.

[David Dunlop]

This Tag Panel is located on the inner, right rear side of the receiver chassis, directly below the 8-Pin PL1A Connector and can be seen in the first photo of Post #579. It holds four identical capacitors and four different resisters. It also has four jumper connections on the back of it and one ground lead, along with being fitted with four leads during its assembly.

The two mounting screws for this Tag Panel are symmetrically located on the panel, but the end with the Ground Lead fitted identifies the top end of the panel for installation.

David

[David Dunlop]

This interesting little component also came off the chassis today.

The total length of the plated copper tube is 5-1/2 inches. Its mounting cleat is soldered in place and is fastened directly to the chassis, holding the smaller Tag Panel covered earlier, in the process - the 5-Tag in Post #608.

1-1/2 inches of the #20 tinned, solid, copper wire extends from each end of the tube. It is suspended in the centre of the tube at each end by means of a small, white, ceramic ‘Fish Bead’, with a small ball of solder on the wire at each end to lock everything in place. The curved end at the top connects to Pin 4 of the Mixer Valve V1C and is covered by another blue sleeve of the type described by Chris.

The lead at the bottom end is also covered by a blue sleeve and connects to a STRIPS, Tag, 1-Way ZA/CAN 4664, the other end of which connects with L16A, the 1st IF Transformer.

What intrigues me about this item is how they managed to keep the bare wire from making contact with the sides of the tube, through the curved section.

David

[David Dunlop]

This is the second from last Tag Panel needing to be removed from the parts receiver chassis and I was able to extract it a couple of days ago. It is also the second of two such 30-Tag Panels used in the receiver. This one is located on the inside face of the lower left side of the chassis. It holds six capacitors, seven resisters, four jumper leads and a ground strap. And as per the earlier PANELS, Phenolic, 30-Tag, it is secured by three asymmetrical mounting screws. .

David