[David Dunlop]

It’s time to revisit these Counters for a few posts. They are an interesting item in their own right and three of them are used in the design of the Wireless Set No. 52 Kit. Two are used on the Sender and one on the Coil, Aerial Tuning No. 2A. The general purpose of all three is identical: to provide a reliable, repeatable, physical reference for tuning either the two PA TUNE Dials on the Sender, or the Coil Aerial Tuning for optimum signal performance. Where it gets interesting, however, is the fact two entirely different coupling drives were developed: one for the two PA TUNE Coils in the Sender and a second one for the Coil, Aerial Tuning. I am not sure why the two versions exist at this point, but they do.

These first four photos focus on the COUNTERS and related Coupling Drive in the Coil, Aerial Tuning No. 2A.

The first photo illustrates the Drive Assembly on the COUNTERS Side of the Coil, Aerial Tuning setup. Note the flat plate with the two studs in it. The second photo shows the corresponding Drive Assembly on the Coil side of this setup. Note the matching plate and pins as per the 1st photo. What ties these two drives together is shown in the 3rd photo, the DISCS, Phenolic, Coupling No. C1 ZA/CAN 4632. In the last photo, you can see how the DISCS sits on one Drive assembly. With the COUNTERS set to “0000”, and the Contact Wheel on the tuning coil wound all the way back to its start point at the left side of the coil, the pins of both Drive Assemblies will be 90 degrees apart and both sides will lock into the DISCS. This design is very responsive. There is no slop in the Tuning Dial and the COUNTERS start responding the instant the Tuning Knob is turned.

Next we will look at what goes on in the Sender with these COUNTERS.


David