Wireless Set No. 52 Canadian - Project

[David Dunlop]

My apologies for this recent diversion from the 52-Set I have been working on, but as I got further down the rabbit hole looking into the Switchboard, Charging No. 5C Mk I Canadian, I realized there were some interesting connections between the 52-Set, this particular Switchboard, Charging and the 19-Set HP that were worth noting. We still do not know the full story of any of this equipment, and perhaps never will, so every little bit of information helps when it can be found.

If we look at 1943, Canadian Marconi Company was working on the No. 9 Mk II/52-Set and they were also involved with the early developmental work on the 19-Set HP. When all of this actually overlapped is still something of a grey area but we do know they were under increasing pressure from approval delays for the 52-Set which eventually turned really bad when a complete rewrite of documentation landed in their laps. Add into that mix the issues they ran across with the early 19-Set HP Amplifier/Supply setup they had to try and solve and something had to give. In 1944 we know CMC was working flat out on production and deliveries of the 52-Set and suddenly Rogers Majestic are in full production of a much improved 19-Set HP, and, as it turns out, a new Switchboard, Charging No. 5C Mk I.

The No. 5C Mk I Cdn Switchboard, as Chris S noted, does have an odd name since no No. 5C exists to have modified into a Mk I version. If we factor in a very likely period of delays and limits to production capability for all manufacturers at the 1943/1944 period of time, I would not at all be surprised that what we see in the name of this new switchboard is nothing more than a typographical error that got missed before the new switchboard went into production. It was very likely intended to be a “Switchboard, Charging No. C5 Mk I Canadian” and its reason for production probably came about during the developmental work Canadian Marconi had been doing on the 19-Set HP. To date, it has never been mentioned in any of the known 52-Set documentation, but now know it was part of the HP Kit for the 19-Set. It provided advantages in the field over its predecessor No. C5 but was fully compatible with any other 19=Set Ground Station setup.

We have few 19-Set HP kits still around from Rogers Majestic and only three know No. 5C Mk I switchboards, but all bear serial numbers below the 300 mark which suggests that both items were in production at RM very close to the same time.
One interesting find in the documentation was a surviving information block for one of the drawings showing it to have been drawn very close to the end of January 1944. See the attached photo. Chances are, all of the drawing were done in this same general time frame, but it is also noteworthy that unlike any of the drawings done for the 19-Set or even the 52-Set, none of the drawings in the 19-Set HP kit in Chris B’s collection were ever converted to print format. I suspect doing so would have added too much time to the overall production process and RM was not in a position to have that happen. It is a shorter process to take finished drawings directly to a shop specializing in Blueprint and Whiteprint production to get the documentation prepped for inclusion in the kits coming down your assembly line, and what was packed with the 19-Set HP Kit in Chris B’s possession are clearly Whiteprints.

So if the drawing work for the 19-Set HP was still underway in late January/early February 1944, actual production movement on the assembly line for the RM version of the 19-Set HP might have started by the end of the 1st Quarter of 1944. It would be interesting to see if any Regimental records provide arrival dates in the field for the 19-Set HP.

Now, hopefully, I will get back to my 52-Set Project.


David