Wireless Set No. 52 Canadian - Project

[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

[David Dunlop]

Back in Post #615, Chris had explained how wiring looms were typically assembled prior to installation in a chassis. With all but one Tag Panel now gone from the parts receiver chassis, the wiring has really been opened up to view.

What I noticed straight away was that two very large sections of loom pass directly under the remaining Tag Panel, so it was clear those looms had to be in place before this Tag Panel was installed. I then started paying a lot more attention to where these two sections of loom went and discovered three more Tag Panels that had these looms running past them in such a way the looms had to pre-exist the panels in the chassis.

The other thing I suspect with regard to the visible looms is that it was not one huge loom to start with, but rather a group of somewhat smaller looms installed in the chassis and where necessary, following their installation, sections of parts of these looms would have been laced together as well, to keep things neat and tidy. This additional lacing may also have gathered in some of the individual leads running between components, where necessary.

Still a bit of a mystery is when the various switches would have been connected up. What complicates that step is both the complexity of some of the switch connections, as well as the very limited space surrounding some switches once installed on the chassis.

In the two photos, the first is the bottom of the chassis with the remaining Tag Panel. Note the large sections of loom passing under the panel from left to right. the second photo is the back of the chassis where the two sections of loom can be seen coming up from the left. Branches of both of these looms headed under additional Tag Panels top and bottom (right and left sides) .


David

[David Dunlop]

This is the largest Tag Panel used in the Wireless Set No. 52 and if located roughly centred on the bottom of the receiver chassis.

As I had noted earlier, a fairly hefty wiring loom passes underneath this Tag Panel in two locations and this shows up well in the first photo attached which shows this location in the receiver chassis once the Tag Panel is removed, along with a few other components, to be covered shortly.

As would be expected with the size of this PANELS, it holds five capacitors, 13 resisters and four jumper cables, along with one Ground Strap. It is mounted to the usual small riveted posts by means of three equally spaced slotted, round head machine screws with external toothed lock washers.


David

[David Dunlop]

As well as its more formal name, this component is also known as the Audio Output Transformer, with a Circuit Reference Number “T1A”.

It is mounted to the side of the chassis, in the lower, front right corner (upper left section of the 1st Photo in Post #620), held in place by four slotted, countersunk machine screws, with external tooth lock washers and hex nuts.

Interestingly, the two rear sets of hardware had thick, spacer/washers between the transformer case and the lock washers. They were serving no useful purpose there, but were the same thickness as the chassis metal. The transformer sat firm and flush to the front chassis, but perhaps at one point in early production, where was not enough clearance for the transformer to fit flush, so spacers were used to give it clearance on the chassis. The spacing issue was resolved but the spacers were never dropped from the production process.

The stamped part number on the transformer case faces out, to the right side of the chassis when installed, with Terminals 3. 4 and 5 on the transformer panel facing the front of the chassis. The transformer appears to be of Canadian Marconi design and manufacture, based on the Part Number Stamp on the side of the case.

The side of the transformer case facing to the rear of the receiver chassis has a pink stamp on it stating, “O.K. TO FILL”.

On the top terminal board of the transformer, the CMC Part Number is repeated, directly above the one stamped on the side of the case. Roughly dead centre is stamped the Circuit Reference Number “T1A’. Stamped in the large space above ‘Terminal 1’ is another large, pink square stamp stating, “TESTED O.K.”, with a round, black CMC Inspection Stamp over top of it.

David

[David Dunlop]

In terms of the 52-Set receiver circuits, this component is the R.F. GAIN CONTROL, Circuit Reference ‘R33A’.

The original manufacturer was C. G. Meredith & Co. Ltd. but I have yet to find anything about them on the web. Probably a long gone company by now.

David

[David Dunlop]

These small CLIPS are one of the simplest designed parts of the receiver so far, but potentially one of the more interesting to sort out when it comes to the assembly work process.

They are used with the eight ARP-3 Valves in the receiver, the V1-Series of valves. All of these grid cap leads are single lead items feeding directly to a contact point on a socket, coil base or Tag Panel.

These two CLIP Leads came from the V1G and V1H ARP-3’s (the only two vertical ones in the receiver) mounted on the lower front left chassis floor, and went straight to a Tag Panel. They feed through a 0.199-inch diameter hole in the chassis floor that is lined with a metal eyelet, to prevent cutting of the lead insulation. As you can see, these holes are located just to the left of the rear socket rivets. A third, similar CLIP lead is located on the upper left back chassis panel next to the socket for the V1F ARP-3.

With each of these three CLIP assemblies, the clip has been soldered to one end of the led, a small yellow sleeve slid up over the soldered end of the clip and the sleeve carefully tied in place with one round of cotton cord. The end of the sleeve over the soldered connection was then lacquered. The sleeves are there to protect the lead insulation from chafing against the slots cut into the valve shield caps through which these CLIP leads pass.

It would make sense, with limited space to work in the chassis itself, that these CLIPS leads were preassembled and delivered to a station on the line for addition to the chassis at an appropriate time.

Similar CLIPS are used for ARP-3’s V1A, B and C across the upper front right rear of the chassis. These three are the shortest Clip leads in the receiver and they were added to the circuits as complete assemblies because the upper shield plate protecting the RF Coil Assemblies has three oversized holes in it to allow the Clips to easily pass through the plate when it is screwed in place, or removed. These three Clip leads, however, have black sleeves fitted to them. Reason unknown at this point in time.

The last two CLIPS are used with ARP-3’s V1D and E and these two leads feed out from inside the respective Coil Shields directly below each valve. The holes these two leads pass through are also 0.199-inch diameter, lined with metal eyelets.

It will be a little while yet before I am ready to remove these coils and shields to be able to have a look inside at the assembly work.

David