Wireless Set No. 52 Canadian - Project

[David Dunlop]

Viewed from the front of the receiver, this is the left hand vertical pair of IF Coils, under Valve V1E, the 2nd IF Amplifier. The upper coil, L19A deals with the input to the 2nd IF Amplifier Valve V1E, and is supported by a pair of Variable Capacitors, C7G and C7H, acting as Trimmers. The Grid Cap Clip lead for V1E feeds out of the shield for L19A.

The lower coil, L18A, deals with the output from the 1st IF Amplifier Valve, V1D and is supported by a pair of Variable Capacitors, C7E and C7F, acting as Trimmers.

In the early production receivers, these trimmer capacitors were quickly identified as prone to failure in humid conditions and were replaced with much better ones and instructions were issued to upgrade the earlier capacitors when found in a set.

For the Grid Cap Clip lead in this Coil Assemblies, a lead wire would have to have been fitted, of sufficient length to exceed what was needed. The lead would have been fed through the shield and soldered in place, once the coil assembly was mounted in the receiver chassis, and a sleeve fitted over the soldered terminal. With the shield then mounted over the coil, the lead could then be trimmed to the required length, a black sleeve slipped over it and the Grid Cap Clip soldered in place. The sleeve was then tied in place. The sleeve on this Clip was a black woven one.

On the back of the chassis wall, six sets of slotted, round head SEMS screws and external toothed lock washers mount the entire coil assembly to the chassis. When the screws are removed, and the two shields up front, the entire assembly can be carefully pulled out of the back of the chassis. Use caution, however, as the black sleeves on the lower soldered terminals of the assembly make the fit quite snug. It does not hurt to compress these two sleeves inward slightly with one hand while extracting the assembly with the other hand, until the sleeves are clear of the rear receiver chassis wall.


David