07-16-2011, 03:55 PM
Those high value resistors drift a lot, so no matter which one they put in, it's a candidate for replacement. 3.3 meg is a modern value and a very good one can be had for perhaps a nickel, when you buy an assortment or stock up your stash. When I recap a radio, I routinely replace any resistor I have to disturb anyway, and most of the time nearly all of them.
You'll want to go slow and careful when you bring this one up. The most critical thing is to make sure the filament string voltage is well within specs, maybe a tad lower. If you need to add a resistor on the last leg of the supply, don't hesitate. Under load, you want to be spot on or under, never over. You will not be able to measure the string without a load with any reliability because you will be dealing with so many variables at the same time, your only option is to go slowly with a variac and measure.
Check back if you get stations on and off with thunder in the background. It'll be the silver mica capacitors in the IF cans. Four out of 5 '42 AND '46 needed help that I am aware of. But there were an awful lot of sets made, so let's not go there unless we have to.
You'll want to go slow and careful when you bring this one up. The most critical thing is to make sure the filament string voltage is well within specs, maybe a tad lower. If you need to add a resistor on the last leg of the supply, don't hesitate. Under load, you want to be spot on or under, never over. You will not be able to measure the string without a load with any reliability because you will be dealing with so many variables at the same time, your only option is to go slowly with a variac and measure.
Check back if you get stations on and off with thunder in the background. It'll be the silver mica capacitors in the IF cans. Four out of 5 '42 AND '46 needed help that I am aware of. But there were an awful lot of sets made, so let's not go there unless we have to.
