Alistair ThomsonThanks Gerry. I’ll open it up and see what I need to do. There is always a way to make it work, and still look OK! Pliable glue would seem to be the best approach with this holder.
I was intent on emptying the cardboard tube containing the four electrolytics – all of which are cacked out – and stuffing them with modern components, but the brown glop filling the tube is rock hard. I chipped a little bit off and applied a heat gun to it, and it melted, but I’m not sure if the heat might also destroy the cardboard case. Any advice?
This is a Marconi 207, and there are two resistors dropping the 390V from the PSU to the screens of the first two stages. The schematic I have comes with a components list, which shows the values of these resistors at 2K6, 2W each. One is burned out and open-circuit, and the other reads 40K, so they have to go. Looking at the current/voltage requirements of the two valves, the 1K3 equivalent of the parallel pair doesn’t make any sense, and the one readable resistor shows a value of 26K, which gives a better V/I environment for these screens. So the correct value is 26K each. Mistakes do get made!
So that’s a warning to not always believe what the manufacturer says in their own docs, even back in 1941 in the days before manufacturers started deliberately telling falsehoods about their products!
