Capacitor CMC 111-225
Firstly today, thank you Bruce for the information on the Hunt Capacitor (Canada) Company, and the acquisition of them by Canadian Marconi Company. Both items are new to me.
I have now found a pair of Canadian Marconi Company capacitors still in place in the Sender, photo attached. I have not yet exactly identified which circuit component each of these capacitors are, but the only available options are, C19C and C19D. C19C will be the V1J Grid A.F. Bypass capacitor and C19D will be the Keying Spark Suppression capacitor. And both have now been added to my list of capacitors to test. Sigh.
The first thing that jumps out at you with these capacitors is the printing. Unlike the Sprague and Aerovox capacitors of similar design, these CMC items are printed around the circumference of the cardboard sleeve, not parallel to the long axis. When you look this capacitor up in the Illustrated Parts List for the 52-Set, the specs are:
CAPACITORS, Electrolytic, 100-uF, 15-V, -10% + 75% with metal cleat 1/4-inch wide, extending 23/32-inch, has a mtg hole 3/16-inch from end. ZA/CAN 4450, CMC 111-225
* The manual indicates ‘No Substitution’ for this capacitor.
The way the printing is arranged, there is a gap in the middle of the capacitor where the cleat sits. Below it I can see ‘MADE IN CANADA’ and possible two other lines. The last appears to say ‘NEGATIVE’.
A quick look around the rest of the Sender shows no other surviving Canadian Marconi capacitors. The next time I am poking about the two receivers I will take a look in them to see it any turn up there.
David
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