Seeking Valves

[Yorkie]

A few points that might help:

Firstly, you'd be much better off using the 8-page GEC data sheet, which is far more descriptive than the sparse two-page Trader Sheet #977.

For example,  the GEC data  has diagrams of all of the valves bases (whichever valves are used in the line-up), and tells you which tag on the valve-holder does what. (Heaters, Anode, Screen Grid, Control Grid etc). It also gives you a table of voltages and current values in a working set, and a chart which gives the colour codes of the eight colours used for the wiring. Obviously that's a great help in identifying which wire is which on the valve bases. There is also a clear diagram of the wave-change switch/coils.

As far as I can tell from the maker's sheet, whatever mix of valves are used, the only valve which has a B7G valveholder is V1 - all of the other valveholders are International Octal (not Mazda Octal).

Personally, before I switched the set on - whether or not through a lamp limiter - the very least that I'd do is to replace the AF coupling capacitor or you risk damaging the output valve and output transformer.  This roles of this capacitor is to pass the AC signal from the IF stage while blocking and DC. However, this capacitor is a known problem whatever the make or model of valve radio, which has earned it the reputation 'that' capacitor. Over time, it becomes leaky in the electrical sense, and can pass DC to the grid of the output valve causing it to draw excessive current, overdriving the valve and stressing the output transformer. On the two-page Trader Sheet that cap is 'C19' and on the 8-page GEC data sheet, it's denoted as C12.  (.02 uF originally, for which a modern polypropylene or whatever cap will be .022 F).

How far you go beyond that point depends on whether you just want to get the set working, 'do it up a bit' or to 'restore it', bearing in mind that it's 65 years old and several components and maybe some of the wiring will be well past their 'best before' date.

I don't know what test gear you have, but presumably a multi-meter for checking voltage, resistance and current. When checking voltages I always clip the negative test lead to the chassis, then you only have to poke around with one test prod - not two. A lot of tests can be done with the set switched off and not connected to the mains - switch continuity, coil and transformer continuity and resistances, valve and dial bulb  filaments, resistor values to see if they're within say 20% of the original values or have gone too high in resistance, and so forth.

Hope that's helpful.

Good luck with the set.