Hello and Good Afternoon, Mr. MacMillan! Nice to hear from you again.
The Type 10 Headgear has been an interesting little side project to work on. Back in the 1970’s and 80’s, I never saw too many of them. I knew they were made with aluminum cases for the microphones and the story at the time was they had been made for tank crews because the Bakelite No. 7 style microphones were too easily broken. End of interest/information, but I suspect the breakage issue for the No.7’s was probably quite real. I was quite surprised, when I opened the first one up to discover it was caste aluminum, not the stamped sheet I was expecting. VERY robust indeed compared to the No. 7 Bakelite mics.
I have limited, dateable documentation covering the Type 10 Headgear, but what I have, from newest to oldest is as follows:
15 Feb. 1945: FZ 526 Issue 1 for the 52-Set
01 Oct. 1944: FZ 256/3 Issue 1 for the 19-Set
Oct. 1944: The Philco publication for WS 19 Mk III Cdn Installation Instructions for Truck and Ground Station. This was clearly a rush publication because the headgear illustrations in it all clearly have No. 7 Mics but are identified at Type 10 Headgear.
08 May 1944: The 52-Set Operators Manual, which has an actual photo of the headgear.
The latter document is interesting since it would have been the reworked version of what had originally been intended as the Operators Manual for the Wireless Set No. 9 Mk II that Canadian Marconi was targeting delivery for in late Winter or early Spring 1944, and which got delayed with British approvals and name change. The original manuscripts were probably written, proofed and delivered to the printers in late 1943 to keep things on schedule, so the Type 10 Headgear had to have been available sometime earlier in 1943 for CMC to have taken advantage of it with what became the 52-Set.
Besides the two complete Type 10 Headgear I have for my 52-Set that are marked top to bottom by Philco and RCA (the RCA markings of which match up with the ones on the Supply Unit Drop Cord photos in the 52-Set Manual) I also have another Type 10 with no RCA stamps, or Philco on the receivers for that matter. No. 2 Brown microphone case with just a yellow C-Broad arrow under the D-ring on the back. Two other sets are devoid of any markings at all and the microphone cases have been NATOed.
My thoughts on all this are that RCA was probably the prime, or sole, maker of the Type 10 Headgear and were approached by Canadian Marconi to supply the needed amount for their 52-Set Contract. Since these types of wireless accessories are never serial numbered, maybe as a means of production control, RCA elected to stamp parts with their logo in the production line to help them identify and separate the Headgear that were to be used to fulfill the CMC Contract?
Either that, or the executives on either company knew each other in the business and social circles well enough the RCA Executives decided to do it just to poke the bear?...
So perhaps today, some Type 10 Headgear survive that were originally part of the 52-Set Contract and many more are out there which were incorporated into other wireless equipment from 1943 (?) onwards.
David
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