First: You should know what a Variac and a Dim Bulb Tester are.

WHAT IS A DIM BULB TESTER?

WHAT IS A VARIAC?

At this point, we are assuming that you have already recapped the radio and replaced the power cable.

With your multimeter, check if there is resistance between the power plug prongs. Turn the radio switch on, but don’t plug it in. Test the resistance between the power cord prongs. You will see resistance. This is the resistance of the heaters of the tubes.

Connect the isolation transformer, then the variac, then the dim bulb tester, then the radio.

Here is how you should turn them on.

Ensure all the devices are connected, and turn the variac to 0.

Turn on all the power switches.

SLOWLY increase voltage to 115VAC

The light bulb should be dimly lit. Initially, the bulb may be bright. But it will dim after a few seconds. This is from the inrush current of warming the tubes. If it is brightly lit, this indicates a short. Unplug and check for shorts.

If it starts making static noises or receiving stations, congrats! You recapped the radio correctly!

If the radio receives stations and sounds good, you should install an inline fuse, modernize it, and then align the receiver.

If it has an issue, it’s time to start troubleshooting. Try the AA5 troubleshooting guide