[David Dunlop]

Although the Blower Motor assemblies for the Sender and Supply Units of the Wireless Set No. 52 are fundamentally identical, they cannot be directly swapped from one component to the other because their respective tag panels fitted to the backs of the motor housing are different.

The blower assembly in the Sender is centred much lower down on the front panel than the blower assembly in the Supply Unit. As a result, there is less clearance above the blower assembly in the Supply Unit to mount any other components.

Each Blower Motor Assembly comes fitted with its own Hash Suppression components for when the fan is operating. These consist of a small RF Choke Coil and a Capacitor. In the Sender configuration, PANELS, Phenolic, 3-Tag, 2-3/8” x 2-1/4” x 1/16” (ZA/CAN 4591) is employed. It is tall enough the large capacitor can be mounted across the front of the Panels above the Blower Motor housing and the smaller RF Choke Coil directly behind it.

With less space in the Sender to work with, Canadian Marconi placed both hash suppression components across the back of the Panels; the capacitor directly above the coil. The circuit references in the Supply Unit for these two parts are C3AJ and L30A and the Panels, Phenolic, 3-Tag, 2-3/8” x 1-3/4” x 1/16” is ZA/CAN 4521.

When I was studying the Blower Motor assembly in the Supply Unit prior to removing it, I had noticed the upper right corner of its Panels, Phenolic, 3-Tag was sitting quite a bit higher than on the left. When I was cleaning the dirt off the blower motor yesterday, I found a large black dash on the top of the mounting strap and this ‘dash’ was located to the right of the large central wiring grommet in the top of the blower motor housing (See photo in Post #805). Looking at this more closely, it appeared that if I loosened the mounting strap enough to turn the dash to centre by the grommet, that might just level out the top edge of the Panels, Phenolic, 3-Tag. I tried it and it worked. So the Blower Motor assembly is now ready to temporarily be reinstalled in the Supply Unit.


David