Wireless Set No. 52 Canadian - Project

[David Dunlop]

Not much work done on the project this past week beyond restocking soldering supplies and getting familiar with the new soldering station.

However, the attached item arrived in the Mail on Wednesday, compliments of Bruce Parker. It has tidied up quite well and the few missing bits should be easy enough to track down. It is now penciled into the project right after I finish getting the two receivers up and running.

The real gem about this Coil, Aerial Tuning unit is that inside, it is still the original, pristine factory No. 2 Brown paint. Not faded at all from exposure to light of any kind for 74 years. It will definitely be the item scanned in for matching when the time comes for painting.

I thought I would now also post another photo of the project overall to date. Had to transfer in another section of wireless bench from the workshop to accommodate everything, but I had planned for that some years back when designing the Wireless Table setup. Top shelf holds the Main Set Receiver and Coil, Aerial Tuning. The lower shelf the Remote Receiver and Case, Remote Supply Unit, Accessories and spare parts receiver. The starting point Aerial Bag and F-Rods is still on the wall. The tea towel on the Main Set Receiver is not original to the 52-Set. It's 'Cat Proofing', held down by a 2-inch binder full of 52-Set literature/reference manuals.

So, some progress is being made after all.

David

[David Dunlop]

Finally finished with the reconnection of the AC Line Cord to the chassis of the ZE-11 Remote Supply. In the attached photo you can see one lead just left of centre, curving past a hex nut and up to a terminal on a toggle switch, and just left of that, the second longer lead arcing up towards the camera and then on down to a terminal on the AC Selector Socket.

Having done that, I plugged in the supply and turned the electrons free. Low tension came in on target at +12V AC, but the high tension output was only +15V DC instead of the anticipated +150V DC. The input voltages to the OZ4 checked out at +201 V AC, so the transformer is OK, Downstream of the OZ4 checked out with the correct amount of resistance, so back to retest the OZ4. Bummer! It came in at barely 8% effective. Can’t really complain. It is probably the original 1943 Marconi OZ4.

Now to track down a good OZ4 and try again.


David

[David Dunlop]

Well, a minty new OZ4 has now been installed in the supply, and even a diode based replacement constructed...just in case. Both work beautifully in another piece of equipment. Not so much in this supply. Sigh.

I should qualify that. They are working just fine but something downstream in the circuit has now reared its head to say hello with a grin! The current suspect is the C25A/B capacitor can that covers both sides of the filter choke. Seems more disassembly and testing is ahead.

This is almost as exciting as taking a CMP apart with a 1/4-inch socket set!

David

[Chris Suslowicz]

You'll almost certainly find that C25 is no longer a capacitor and needs re-forming or replacing. Old electrolytic caps lose the insulating layer on the plates/foil over time if not used, and act as resistors instead. If power is applied they can explode due to a build up of pressure caused by electrolysis.

There are ways round this, using a variable voltage supply to bring it back to life slowly, or a "proper" re-forming unit that applies pulsed DC in an attempt to re-form the aluminium oxide insulating layer.

Chris.

[David Dunlop]

With the assistance of Jacques Fortin, I was able to find an original replacement C25A/B capacitor for the Remote Supply. It should arrive next week and it will be great to get that portion of the project back on track.

In the meantime, I have been reading through the 2” binder of 52-Set manuals I have accumulated, and realizing I should have purchased a 3” binder, as more documentation keeps popping up.

In the process, a mystery has surfaced in the Master Parts Identification List for the 52-Set, that I want to put out to everyone for review. I will preface that comment by stating whoever did the proofreading for this document back in 1944-1945 did a great job. Quite a few corrections are noted in the descriptions. As an example, the canvas cover that rolls down over the front of the Carrier Assembly should be correctly identified on the front of it as a ‘COVER’, but some early production of the item marked it as a ‘CURTAIN’ and that term is to be disregarded.

Now to the mystery. My understanding of the 52-Set production run from CMC, is that the early sets were finished in the same wrinkle olive green as the preceding Wireless Set No. 9 Mk I Cdn. This was then switched to No. 2 Brown wrinkle finish, which covered the bulk of the production run. Finally, there is the possibility that the colour switched back to wrinkle olive green close to the end of the production run.

Where it gets interesting in the Illustrated Parts List is that the colour ‘Khaki’ is mentioned for the finish on the three spare parts and tool boxes and once for the case used on the Remote Receiver. In another location the Remote Receiver Case is referenced as being ‘Brown’ . The Main Set Carrier is always referenced as ‘Brown’.
The canvas carrier cover previously mentioned is always referred to as ‘Brown’.

The Serial Numbers of the parts I have found run from the high 7,000 range to the high 8,000 range. The interior of the ATU I received from Bruce Parker is finished in No. 2 Brown, and it has the SN 8963, so I am confident that if all relevant parts are eventually finished in wrinkle, or flat, No. 2 Brown, I will be OK. And a brown canvas for the cover should be easy enough to track down. But the reference to ‘Khaki’ puzzles me. I do not recall ever seeing it as a reference colour before on anything vehicle or signals equipment related, other than canvas goods. No. 2 Brown is so distinctly brown it seems hard to think it would be called anything else, so I am thinking ‘Khaki’ must be an error.


David

[Bruce Parker (RIP)]

I'm not sure khaki is inconsistent. Radio colours matched truck colours to a degree, the big differences being that early radio equipment had a dark green that wasn't matched on vehicles, and I'm pretty certain no radio gear was ever painted 'light stone' from the factory. A good deal of mid war radio ancillary parts (spares and parts boxes, splitters, signal lamp battery boxes come to mind) were khaki, as were trucks prior to 1943.

Originally Posted by David Dunlop

With the assistance of Jacques Fortin, I was able to find an original replacement C25A/B capacitor for the Remote Supply. It should arrive next week and it will be great to get that portion of the project back on track.

In the meantime, I have been reading through the 2” binder of 52-Set manuals I have accumulated, and realizing I should have purchased a 3” binder, as more documentation keeps popping up.

In the process, a mystery has surfaced in the Master Parts Identification List for the 52-Set, that I want to put out to everyone for review. I will preface that comment by stating whoever did the proofreading for this document back in 1944-1945 did a great job. Quite a few corrections are noted in the descriptions. As an example, the canvas cover that rolls down over the front of the Carrier Assembly should be correctly identified on the front of it as a ‘COVER’, but some early production of the item marked it as a ‘CURTAIN’ and that term is to be disregarded.

Now to the mystery. My understanding of the 52-Set production run from CMC, is that the early sets were finished in the same wrinkle olive green as the preceding Wireless Set No. 9 Mk I Cdn. This was then switched to No. 2 Brown wrinkle finish, which covered the bulk of the production run. Finally, there is the possibility that the colour switched back to wrinkle olive green close to the end of the production run.

Where it gets interesting in the Illustrated Parts List is that the colour ‘Khaki’ is mentioned for the finish on the three spare parts and tool boxes and once for the case used on the Remote Receiver. In another location the Remote Receiver Case is referenced as being ‘Brown’ . The Main Set Carrier is always referenced as ‘Brown’.
The canvas carrier cover previously mentioned is always referred to as ‘Brown’.

The Serial Numbers of the parts I have found run from the high 7,000 range to the high 8,000 range. The interior of the ATU I received from Bruce Parker is finished in No. 2 Brown, and it has the SN 8963, so I am confident that if all relevant parts are eventually finished in wrinkle, or flat, No. 2 Brown, I will be OK. And a brown canvas for the cover should be easy enough to track down. But the reference to ‘Khaki’ puzzles me. I do not recall ever seeing it as a reference colour before on anything vehicle or signals equipment related, other than canvas goods. No. 2 Brown is so distinctly brown it seems hard to think it would be called anything else, so I am thinking ‘Khaki’ must be an error.


David

[David Dunlop]

This little gem arrived earlier in the week from Jacques Fortin and I would like to thank him on two counts. First, for the presence of mind a number of years ago to carefully disassemble a surplus remote supply unit and save the parts, rather than simply tossing the entire item. And secondly, for taking the time to search his parts to locate it and make it available to me.

Factory rated for 20uF on both sides when new, it currently checks out at 21uF and 27uF. I can now desolder the suspect capacitor in my ZE-11 Remote Supply and test it against this one to see which one is healthier. I was reluctant to pull the existing cap until I knew I had a suitable replacement, so that all potential work could be done in one sitting. A necessary consideration when dealing with an electronics work bench that is not cat proof.

David