Wireless Set No. 52 Canadian - Project

[David Dunlop]

A rather eclectic weekend of 52-Set work has just passed.

First and foremost, with the help of a lot of colourful muttering to myself, I was able to tune all the Trimmer Capacitors in the IF Coil and RF Coil Assemblies of the Remote Receiver. It helped a little bit, but not enough to get rid of the chopped Zero Beat Tuning phenomenon. I am going to have to bite the bullet and retune all the related coils. That will be a real challenge as two of them carry a HUGE amount of electrical potential and a proper insulated adjustment screwdriver is essential for that work. So I will have to schedule humping the Remote Receiver to my friend’s place down the road to finalize the adjustments this receiver needs.

With that out of the way, I decided to revisit the Sender to see why the aerial feed between it and the Receiver lacked continuity, so out that brute came from the Carriers No. 4 for a closer look.

A close inspection of the suspect Relay Switch proved it was in perfect working order and so was the Band Switch. That brought me back to the Aerial Output Socket on the Sender. I discovered two things there. First, the screw holding the Plug on the end of the Aerial Feed Cable was loose. Turned out an internal toothed lock washer was missing and the Plug was loose enough on the terminal fitting of the cable to produce intermittent isolation. Second, the Plug itself was a very loose fit in the Aerial Socket. Every other similar socket on hand produced a very snug fit for the Plug. By gently sliding a small slotted screwdriver between the four Socket Tabs and the Sockets large Bakelite housing, I was able to close up the gap for a much better Plug fit.

When getting ready to put the Sender back into the Carriers No. 4, I found the lower Shakeproof Cowl Pin on the Blower Door would not unlock. I have found it very helpful to have this door open when reinstalling the Sender in the Carriers No. 4. It provides easy access to the Sender chassis to nudge the Sender fully home. The two Knobs on the lower part of the Sender do not provide enough leverage to move the mass of the Sender in its upper portion where the two 8-Pin Connector Plugs need to link up. A careful look behind the Sender Panel revealed the Locking Pin in the Shaft of the Lower Shakeproof Fastener was falling out. I then remembered it was a much looser fit when installing it than the upper one. I was able to get it out and replace it, but this time let a little clear nail polish wick into the pin hole to hold it in place. Those two Shakeproof Cowl Fasteners on the Sender Blower Door still are a mystery. The upper one I have is shorter than the lower one and does not engage the Receptacle on the Sender Chassis at all. The lower one works just fine. Two more exist on the Receiver Section of the Supply Unit. The Parts List gives three Shakeproof Cowl Fasteners in use on the 52-Set but no reference at all to which ones go where. I am going to have to resort to a survey of all owners of surviving 52-Sets to determine what they have in their sets and see if some consistency turns up for working fasteners in both locations.

Once the Sender was back in the Carriers No. 4, I reconnected everything and fired it up once more. Happy Dance! I had full continuity from the Receiver all the way through to the dipole aerial outside. Even nicer to hear for the first time, were the changes in audio output in the Receiver when the Sender Band Switch was changed to and from the same Band at the Receiver was set to, and the three Tank Coils used in the Sender to tune it and the Receiver to the aerial in use, were finally working. Now I just have to get the Coils, Aerial Tuning No. 2A linked into the system.


David

[David Dunlop]

Several years back I had purchased a preassembled 12-foot Aerial Connector Cable Assembly for use with an FRG-7 I owned at the time. It was a run of RG-58A/U Coax with a UHF Plug at each end. The first time I tried it; the Central Conductor of one Plug jammed in its Socket and tore out of the Plug Assembly. A close inspection showed the Plugs used were cheap; using folded central pins, rather than rolled ones. The folding was off, creating one large sized face that stuck. Set the cable aside and forgot about it.

This morning I dug it out of a bin and decided to lop off the duff end and convert the cable to a small ring terminal at that end to allow for the future fitting of a turned brass PLUGS, Aerial. The type that sits at 90 degrees to its cable and has a cheese head BA screw holding it in place. I could then use this coax cable to connect either of my two 19-Sets, or my 52-Set to my external dipole aerial.

I got the job done this afternoon, and decided to see how the Main Set Receiver reacted to officially being connected to the dipole through all its proper fittings. I use ‘proper fittings’ carefully because at the moment, the Connector between the Sender Output Socket to the Coils, Aerial Tuning No. 2A, is about 4 times longer than it should be and that might be putting a bias into the works for a while.

It was so much fun listening to the WWV Time Signal at 5.0 MC slowly improves as the Sender and Coil Tuning came into play. I cannot help but wonder when the last time was, here in Winnipeg, when the Receiver of a complete 52-Set operated this way.

The three photos are of the cable I reworked for the task, the 52-Set up and running with all bits finally interacting and the output feed to the dipole on the wall, with the running CPP-2 Power Supply doing its thing on the lower shelf. If you look carefully in the last photo, you can see the output leads from the CPP-2 connected to the DC Voltage Distribution System I built for the Wireless Bench. On the back wall, just above the bench and between the two 19-Sets, you can also see the Battery Cable for the 52-Set connected to one of the 3 Distribution Boxes in the system.

A big thanks to Bruce Parker at this point once again for sending me the spare Coils, Aerial Tuning No. 2A he had on hand when I started this crazy project. Between it and what I had on hand, I now have a complete and functioning Coils and was even able to send a couple of spare bits to a fellow 52-Set Restorer in Northern Ireland to help with his work.


David

[David Dunlop]

This Project is at a very interesting point right now in that the pieces I have been working on for the last three years are finally interacting with each other to some degree. Kind of like when pieces of a vehicle start coming back together in a meaningful way. The timing for this is very good since I have to step away from the Receivers and Sender for a couple of weeks and I can take the time to review the work done to date to identify details I have missed, or not fully recognized the importance of, in my restoration work to date. For example, the noisy tuning coils in the Sender. I have now discovered these since the Receiver can once more interact with it as it as it was intended.

In addition to the three Aerial Loading Coils located in the Sender, there is also the much larger Coil, Aerial Tuning No, 2A that sits on top of the Carriers No. 4. The latter item is noisy throughout its tuning range, which is not the least bit surprising, since I have done no internal cleaning of that assembly at all so far, It will eventually be carefully disassembled, however, in order to restore the paintwork inside and outside of the wooden case, to return it to original Marconi Semi Flat Olive Green. At that time the Coil Assembly and its related WHEELS, “V” Contacts, will be fully cleaned.

As for the coils in the Sender, I did clean all of them of the sooty residue covering them, but did not pay as much attention as I should have to their related WHEELS, “V” Contacts. The result is intermittent scratchy spots on them as they tune throughout their ranges. The same effect as you hear on an old radio or television volume control that needs cleaning. What I think I will do in the interim is set the two sets of coils back to their start points of ‘0000’ on their Counters and then run them both full range, recording the Counter Values at every noisy section. Then, once I can get back to working on the Sender again, I will be able to find each spot on the coils that needs attention, as well as giving the WHEELS “V” a good cleaning.

The other thing I will be focusing on for a while will be a careful study of the actual Operating Procedures for the 52-Set. I need to be far more comfortable with the process than I currently am, and that only comes with reading, learning and practise. The Working Instructions Manual has good information for this but it does tend to be spread out through the manual a bit, which makes the flow of the information a bit choppy. On the bright side however, I discovered that some time ago, I had obtained a copy of the TELECOMMUNICATIONS FZ 523 1st Echelon Work for the Wireless Set No. 52 Canadian. Issue 1 dated February 1945.

This is an excellent training source, covering all the operating steps in a very nicely arranged sequence. It also has a wealth of useful Operators Reference material, troubleshooting information and Maintenance Data. One thing I did notice is you have to pay attention to what piece of the 52-Set they are discussing when it comes to working with the Meter, which is mounted in the Receiver, but services the Sender as well.

On the Receiver, the switch for the Meter is called the ‘METER SW.’, but on the Sender the switch is identified as ‘METER SWITCH’. In order to activate the METER SWITCH on the Sender, the METER SW on the Receiver has to be turned to ‘SENDER’.

See what I mean?


David

[David Dunlop]

Two weeks past cataract surgery on my right eye and so far so good. One good eye and one blurry eye definitely wreaks havoc on one’s ability to perform detail work, however. Even trying to read up on operating procedures has its challenges. Sigh! Two more weeks and the other eye should be done, so fingers crossed.

In the meantime, while looking for things I can actually accomplish, I stumbled across my old A and B Lists of things to find for the 52-Set Project. A surprisingly large number of things could be crossed off both lists now, which was encouraging.

Close to the top of the list overall now is the CURTAINS, Waterproof to install across the top front of the Carriers No.4. Be interesting to learn how these were originally packed from the factory; tagged and packed in sets in boxes, or individually rolled and wrapped in brown paper? Could have gone either way I suppose. Also be interesting to learn who made them.

David

[Chris Suslowicz]

Originally Posted by David Dunlop

Two weeks past cataract surgery on my right eye and so far so good. One good eye and one blurry eye definitely wreaks havoc on one’s ability to perform detail work, however. Even trying to read up on operating procedures has its challenges. Sigh! Two more weeks and the other eye should be done, so fingers crossed.
David

For reading (assuming the un-blurred eye is the fixed one and you chose "distance vision") I'd suggest a pair of cheap reading glasses and tape over the lens for the blurry eye. (If the eyes are too far apart in terms of focus distance you won't be able to correct with a lens and get stereoscopic vision because of the difference in perceived image size - which is why they do both eyes.)

Best regards,
Chris. (Who has been "fixed focus" for a number of years now.)

[David Dunlop]

I was just going through some old notes on this part and rediscovered an oddity.

Every so often, one sees one of these HOLDERS with a thin disc of grey felt, or perhaps cork, placed at the back of it, over the three mounting screws.

Were these thin pads an actual production/supply item, or were these just ‘local level fabrications’, to reduce rattle of the pocket watch in the HOLDERS?

David

[Bruce Parker (RIP)]

Originally Posted by David Dunlop

I was just going through some old notes on this part and rediscovered an oddity.

Every so often, one sees one of these HOLDERS with a thin disc of grey felt, or perhaps cork, placed at the back of it, over the three mounting screws.

Were these thin pads an actual production/supply item, or were these just ‘local level fabrications’, to reduce rattle of the pocket watch in the HOLDERS?

David

I think there had to be a felt or cork backing. Otherwise the watch flops about in the case no doubt straining and ultimately chipping the socket at the top. My question is whether the watch was removed to wind it...which would be a very often occurrence. If so the fragile threads on the case would no doubt cause trouble very quickly (and it's not an easy item to remove and replace). On the other hand it is very difficult to pull up the knob and wind the watch while in its case. The 52 set probably would not be that bad but the watch and winder (not to mention the case itself) is not very accessible on Mk.II 19 sets.

[Bruce MacMillan]

Originally Posted by David Dunlop

I was just going through some old notes on this part and rediscovered an oddity.

Were these thin pads an actual production/supply item, or were these just ‘local level fabrications’, to reduce rattle of the pocket watch in the HOLDERS?

David

My 2P worth thinks it was local. I had bought an unopened box of 6 watch holders and upon opening there were just the holders, no extra bits. I've found no documentation on field changes with the holders or stores numbers for the backing. Looking at the many photos on google where the holder is visible none have padding. I think the solution (has been verified) was to remove the offending watch and store safely in a padded pocket.