[David Dunlop]

A little diversion.

A couple of these Supply Units have recently shown up on the UK eBay site. They do, from time to time, but these two were useful as they had a lot of photos to examine and they were still in worn, but original factory paint and markings. A rare thing on this side of the Atlantic.

What struck me on both was that directly above their data plates, which are centred on the back of the chassis plate, was a stamped, four digit number which had been carefully varnished over to protect it. Finding one such arrangement would have been nicely odd, but two of them strongly suggests these numbers were important. My thinking went straight to them being yet another version of a Production Control Number for these supplys used until the final data plates were attached to the units.

Unlike the other components of the 52-Set where these 4-digit numbering system show up, neither of these were close to the final assigned serial numbers on their data plates, but both were very close to being 4,800 numbers lower. That is getting remarkably close to the possible total production run of 52-Sets, of around 5,000.

Close to 90% of the design of the ZE-11 Supply used with the Wireless Set No. 9 Mk I Cdn was carried over into the ZE-12 Supply that formed part of the 52-Set. Over the years of this project, I have heard a few independent stories that CMC encountered some production delays in getting the ZE-12 built. I am sure whatever those delays were, they could not have shut things down for the bulk of the 52-Set production run.

Some of these stories further related that Canadian Marconi Company was able to maintain full production flow by simply producing an extended run of ZE-11 Supply Units short term, to fill the gap. Chatting with Jacques Fortin about this earlier today, he confirmed that when he bought three surplussed fully equipped Cases, Operating Remote for the 52-Set back in the 1970’s, two came equipped with ZE-12 Supply Units but the third one contained a ZE-11. So perhaps, any Production Control Number system that was up and running for the ZE-11 Supply Unit was simply continued while ZE-11’s were built for the 52-Set and nobody bothered resetting it once the ZE-12 came on line.

Be nice to find more of these paired up numbers to see what they have to say. I also now have to take another closer look at my own ZE-11 Supply Unit. It came with my Remote Receiver for the 52-Set and these receivers used the same connector cable in both the 52-Set Remote and No. 9 Mk I Remote configurations.


David