Wireless Set No. 52 Canadian - Project

[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

[David Dunlop]

I have no idea what the correct nomenclature ID is for these parts, but they are the terminal tag strips from inside the 8-pin connector assemblies used to connect the three main set components to one another in the Carriers No. 4.

These parts, along with the rectangular blade contacts from the plug assemblies are not listed in the Master Parts List. The complete, various 8-pin plug and socket assemblies are covered, as are the leaf type socket connectors. Perhaps these terminal tag strips and the blade connectors were considered robust enough to never need replacing. By comparison, you can see a lot of stretched and broken leaf connectors from having had screwdrivers jammed into them in an attempt to turn their retaining screws, which is a totally incorrect way of trying to work on these connectors.

The parts must show up in another manual reference somewhere.

David

[David Dunlop]

As per the attached illustration from the 52-Set Master Parts List, the Crystal Calibrator in the receiver is serviced as a complete unit. In reality, it is made up of three sub-components, from back to front: the calibrator chassis, the extension assembly that gets the calibrator panel far enough forward to line up with the upper front panel of the receiver, and the calibrator panel assembly itself that includes the switch and indicator lamp.

When installed in its location in the upper left corner of the rear chassis wall of the receiver, there is only a ¾-inch clearance between the side of the calibrator assembly and the left side wall of the receiver chassis and the front of this receiver side wall bends inward ¾-inch to support the upper front panel of the receiver when it is in place. Two slotted round head screws and external lock washer sets secure either end of the calibrator to the rear chassis wall of the receiver.

I suspect that the assembly line station where the crystal calibrator was installed into the receiver chassis was equipped with an overhead, flex cable driver rig similar to a dental drill. It probably had an angle head with interchangeable bits and would have worked easily to mount the calibrator quickly. Once mounted, three leads on the right side of the calibrator chassis would have been soldered in place: HT, 12 Volt and OUTPUT, and the e installation would be done.

However, to remove the crystal calibrator from the receiver, one first has to remove a pair of slotted, round head screws and external lock washers on the bottom side of the union between the calibrator chassis and the extension assembly, and a pair of slotted, pan head screws only at the top union. The loose section of the calibrator can then be swung to the right side enough to get a ¼-drive socket and extension in place with a slotted driver head to undo the four screws mounting the calibrator chassis to the receiver.

Best to unsolder the three leads to the calibrator first, however,

The innards of this calibrator are quite similar to the one designed for the Wire Set No. 19.


David

[David Dunlop]

When my first 52-Set Receiver arrived and I had a look at the inside of it, I had noticed a four digit number scratched into the metal on the left side chassis wall about midway up the back end of it. In addition, the same number appeared in large black grease pencil, or paint. My initial thought was it might have been the serial number of the receiver added to the chassis during production, but the number did not match the data plate. Same thing was noticed when the other two receivers eventually arrived. So I filed the information away and forgot about it essentially.

When I removed the Crystal Calibrator from my Parts Receiver the other day, I was quite surprised to find another four digit number written in grease pencil, or black paint, on the inside chassis wall of it as well. As per the attached photos, this calibrator number is ‘6641’. The number inside the Parts Receiver is ‘6215’. Not identical, but interestingly close.

I am thinking now, that these numbers are perhaps Production/Assembly Control Numbers used on the various lines for data gathering and quality control. If these numbers were logged in and out at each work station on the line, at the end of each shift, it would be easy to determine the number of assemblies processed each day, for example. Or if defects showed up, it would be relatively easy to isolate the range of assembles that would need to be inspected and/or corrected.

I will have to check for these numbers in the Sender and Supply Unit and Remote Supply as well now.

David

[Chris Suslowicz]

Originally Posted by David Dunlop

I have no idea what the correct nomenclature ID is for these parts, but they are the terminal tag strips from inside the 8-pin connector assemblies used to connect the three main set components to one another in the Carriers No. 4.

These parts, along with the rectangular blade contacts from the plug assemblies are not listed in the Master Parts List. The complete, various 8-pin plug and socket assemblies are covered, as are the leaf type socket connectors. Perhaps these terminal tag strips and the blade connectors were considered robust enough to never need replacing. By comparison, you can see a lot of stretched and broken leaf connectors from having had screwdrivers jammed into them in an attempt to turn their retaining screws, which is a totally incorrect way of trying to work on these connectors.

The parts must show up in another manual reference somewhere.

David

Probably not: they're a Canadian Marconi item and probably only available as a complete unit, configured to the actual application. (Especially given the difficulty of changing an individual contact without wrecking the spring.)



Chris.

[David Dunlop]

Hi Chris.

I had forgotten about the ‘in house’ factor of these connectors at Canadian Marconi. They were also using them with some wartime navy wireless equipment and the WS No. 9 Mk I Cdn.

I am going to have to make an effort to get a copy of the Master Parts List for the Wireless No. 9 Mk I Cdn to better understand how much of the bits from it carried over into the 52-Set.

David

[David Dunlop]

This smaller Tag Panel supports a pair of capacitors and a single resister and can be seen in the photograph in Post #598, in the upper left quadrant, its mounting bracket secured under the small cleat retaining the tubular, plated copper lead shield.

Other than a pair of single capacitors held in place by cleats in a couple of places on the chassis, this Tag Panel is probably the easiest to remove so far.


David

[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