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

[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

[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

[David Dunlop]

The location of this part can be seen in the first photos of Posts #619 and #620, directly below the T1A Transformer.

The Circuit Reference for this resister is ‘R14A’ and it is the Meter Adjustment used for calibrating the Meter. It is reached by means of the long slotted screwdriver in the Tool Kit from directly above, between the Flick Drive Assembly and the Tuning Condenser. The adjusting slot is visible immediately to the left of the Flexible Tuning Drive Coupling, when you look straight down in that location.

It appears to be another ‘in house’ CMC product, with its CMC Part Number stamped into the rear cover of the resistor case, ‘115-294’.


David

[David Dunlop]

This JACKS assembly is oriented vertically in the lower right front corner of the receiver, with Circuit References J2A and J2B.

I have left the SWITCHES, Toggle, DPDT No. C3 (ZA/CAN 4669), circuit reference S4A, still attached for future reference.

The first photo shows the two components more or less oriented as they are on the chassis. Approximately three inches of the lower chassis plate are bent down to form the lowermost front wall of the receiver chassis. The Switches along this three-inch strip all mount directly to the chassis and the lower front receiver panel has large enough cutouts to drop down over the mounted stitches.

The JACKS, Telephone, on the other hand gets installed along with the switches, but is not mounted until the lower receiver panel is in place. External tooth lock washers sit between the front face of the JACKS assembly and the back of the lower receiver chassis plate.

The second photo shows the side of the JACKS that faces to the interior of the chassis: towards its SWITCHES S4A located immediately to the left of the JACKS. The body of the JACKS is cast Bakelite and two slots on the inner face hold the two spring metal contact strips that secure the Phone Plugs when inserted into the JACKS. The retaining hardware for these two springs also serves as the mounting points of the electrical leads to the JACKS.

The last photo shows the side of the JACKS facing to the outside right of the chassis where the mounting hardware for the two contact strips is secured with an internal tooth lock washer and a pair of hex nuts each fitting.



David

[David Dunlop]

This is the last of this type of switch used in the 52-Set Receiver. This is the TONE FILTER Switch, located on the lower left front of the receiver, between the Mode of Operation Switch and the Meter Switch. Its circuit reference is S4C.



David

[David Dunlop]

The full Nomenclature for this component is, SWITCHES, Rotary Disc, SP, 12-Position, 2-Bank, No. C1, and its circuit reference is S3A. It is more commonly known as the ‘Meter Switch’.


David

[David Dunlop]

The full name for this switch is, SWITCHES, Rotary Disc, 2-Pole, 4-Position, 3-Bank, No. C1 ZA/CAN 4207 and its circuit reference in the 52-Set receiver is S2A. It is the ‘Mode of Operation’ Switch located in the extreme lower left front of the receiver.

This switch sits very low in the chassis, which in the case of this receiver was its undoing. Somebody put the receiver down on a workbench, or other surface, at one point without checking to be sure the surface was clear. The result, if you look closely, is that the middle switch contact wafer was shattered.

These switches are designed to be repairable and a large surviving chunk of the 2nd to 4th Echelon Maintenance Manual is devoted in detail on how to do just that. However, one needs spare wafers in order to affect those repairs and the work required is substantial. Hence, this receiver became my parts receiver.


David

[David Dunlop]

I covered off the improvements to these DRIVES that CMC made when I was restoring the Sender last year. You can definitely feel the difference in weight between these assemblies and the ones in the Wireless Set No. 19 once they are free from the chassis. Better quality parts, higher machining standards and more reinforcement would have gone a long way in reducing the physical wear which resulted in sloppy tuning stability.

And it makes sense when you think about it. The intent of these DRIVES was to allow the Operator to pre-set two different communication frequencies – typically a day and a night frequency, so these drives had the potential of being swung back and forth, stop to stop, at least twice a day. No wonder one of the frequent complaints CMC got from Operators was the loss of ability for the Drives to reliably move to frequency repeatedly, over time.

The frame of these Drives is slightly thicker than on the 19-Set Drives and you can clearly see the solid, bronze alloy triangular blocks CMC used to stiffen the top outer mounting corners. On the 19-Set Drives, these corners were simply created by bending the frame sheet metal over in these areas.


David

[David Dunlop]

This Couplings connects the shaft at the back of the DRIVES assembly to the shaft at the front of the Tuning Capacitor, directly behind the Drives in the chassis.

At first glance, it looks very much like a simple coil spring assembly, but in fact; it is a thin sheet steel bellows construction. Note there is no ‘coil’ present, just a parallel set of ‘rings’.

A collar is fitted at each end and each collar has three 8-32 Grub Screws set 90 degrees apart to secure the Couplings to both shafts it connects. These bellows remind me of the much larger ones found in fancy aneroid clock work barometers from days gone by, only they were typically fashioned of copper or brass, back when scientific instruments were works of art.

Interestingly, when I removed this coupling, I marked the two shafts to see where the Coupling actually was mounted. I am glad I did. Nearly 5/8-inch of shaft was under the Coupling at the DRIVES end but with less than 3/16-inch under the Tuning Capacitor shaft end, the grub screws were barely hanging on. Something to be wary of if I am ever servicing one of these parts again, down the road.


David