Wireless Set No. 52 Canadian - Project

[David Dunlop]

As I noted back in Post #859, it took a little while to ‘connect the dots’ between the strange set of nine numbered symbols I had first noticed on the Sender Circuit Diagram on Page 203 of the 52-Set Operators Manual, and the actual hardware mounted in the Sender chassis. It was this particular panel, hiding in plain sight, that I finally saw for the first time and allowed me to understand the symbols. The attached photo clearly shows how obvious this panel actually is, if ones eyes are truly open.

I still do not know why these four terminals had to be numbered in reverse order, but they were. This photo also shows the stamped numbers in the phenolic panel very well (common to all three such panels) as well as how the ring terminals and sleeves are set up on the wires connected to the terminals. This feature is also common to all three panels.

Terminal 6 is set up between S13A and C8D, the Grid Coupling Capacitor for V7A (813), L34B, the V7A Grid RF Choke, C26G, the V7A Grid RF Bypass Capacitor and S16A, the Mode of Operation Switch. Also tied into it is R8A, the Parasitic Suppressor feeding to Pin 4 (Grid No. 1) on V7A. This all caught my attention since the Pin 4 circuits are giving me the bulk of the bad readings for V7A at the moment.

Terminal 7 is between S13A and C27F on Pin 3 of V5C, the Plate Coupling Capacitor, L43A, the V5C Grid 7 – 16 MC Tank Coil, and C17A, the variable V5C Plate Tuning Capacitor.

Terminal 8 is between S13A and L34C, the V5C Grid RF Choke, C27F on Pin 3 of V5C, the Plate Coupling Capacitor, and R39C, the V5C Screen Voltage Dropping Resister, and R7E, the V5C Screen Parasitic Suppressor on Pin 4 of V5C.

Terminal 9 is the last of this series of screw terminals. It is situated between S13A and R57A and R57B, a series set of 600,000 Ohm HT Metering Resisters, and C26H, the V7A Screen RF Bypass Capacitor connected to Pin 3 (Grid No. 2) on V7A. This circuit is now also of interest since the meter reading for the Sender HT Circuit was only giving me 110 Volts DC (+/-) when the Supply Unit was running, and the actual readings should be either 300, or 600 Volts DC, dependant on whether one, or both of the Supply Unit Dynamotors are running.
So it looks like the time it took to trace out what these nine terminals are doing in the Sender was a worthwhile effort as it gave me a better focus on where two of the major problems with the Sender circuits might be located.

David