[David Dunlop]

For such a small, and electronically simple component of the 52-Set, this coil assembly holds an amazing number of mysteries for me and they just keep popping up!

In fairness to the Engineers and Designers at Canadian Marconi Company 80 years ago, a fair bit of these mysteries are probably directly related to my limited practical and theoretical electronic knowledge related to this calibre of wartime wireless equipment.

The first, and still current mystery, revolves around the existence of the small cylinders found mounted just below the tuning gear drive assemblies on the right side plate of the coil chassis as per the first photo. They are not physically connected to any circuit in the entire coil case, just the 1/4-inch resin side plate. My first thought was they contained a coil intended to balance out the presence of the large mass of metal present with the tuning gear drive next to it.

Last night, however, I discovered these cylinders are not hollow. The ends of the two I have available to study finally revealed they are a tight roll of resin impregnated fabric. It is still possible that a very fine weave of non-ferrous mesh, or foil, is wrapped up within the coils of fabric, and these cylinders are serving some form of electronic purpose.

A new ‘longshot’ idea is these cylinders are nothing more than a spacer, or guard, to protect the tuning gear drive from getting knocked out of alignment when the coil assembly is removed from its wooden case. I say ‘longshot’ because a 2-inch piece of 3/4-inch wooden dowel would have been a far cheaper and simpler solution for this type of problem.

Adding to this mystery is the complete lack of reference anywhere in the 52-Set documentation to these resin cylinders.



David