I recently began restoration on this beautiful console radio from the early 20's. I am unable to get the "receiver" section of the radio to light up. The power supply tubes and receiver tubes all test fine, and the speaker has a slight humm. Any ideas on how to approach this problem? The tubes in the receiver section sit on a metal cannister of some sort.. Thanks. Dave

Hi,
You may have shorted filter caps which would draw down available current to the rest of the radio. If you pull the tubes out of the radio section and check the filament voltages- the 26's should test around 2.5 volts, the 27 should test around 1.5, and the 71 should test around 5 volts. The 26 tubes draw slightly over 1 amp each, so you may have the voltage for the filaments present, but the current may not be adequate, and that would reveal itself by plugging in one tube at a time.

While testing, watch the plates of the 80 to see if they glow red, if they do, the problem is in the power supply.

If no voltage is present at all, the power transformer might be burned out.

Use care when removing the two chassis, because there was no provision for handling them seperate- I know this from when I scrapped one out.

: I recently began restoration on this beautiful console radio from the early 20's. I am unable to get the "receiver" section of the radio to light up. The power supply tubes and receiver tubes all test fine, and the speaker has a slight humm. Any ideas on how to approach this problem? The tubes in the receiver section sit on a metal cannister of some sort.. Thanks. Dave

Hi Dave

The Radiola 30A should use 99 tubes with series wired filaments. If any filament is open, none will light. Also due to silvering in these tubes the filament may be hard to see.

Your 71A should be lit as it gets voltage directly from a power transformer.

Norm

: Hi,
: You may have shorted filter caps which would draw down available current to the rest of the radio. If you pull the tubes out of the radio section and check the filament voltages- the 26's should test around 2.5 volts, the 27 should test around 1.5, and the 71 should test around 5 volts. The 26 tubes draw slightly over 1 amp each, so you may have the voltage for the filaments present, but the current may not be adequate, and that would reveal itself by plugging in one tube at a time.

: While testing, watch the plates of the 80 to see if they glow red, if they do, the problem is in the power supply.

: If no voltage is present at all, the power transformer might be burned out.

: Use care when removing the two chassis, because there was no provision for handling them seperate- I know this from when I scrapped one out.

: : I recently began restoration on this beautiful console radio from the early 20's. I am unable to get the "receiver" section of the radio to light up. The power supply tubes and receiver tubes all test fine, and the speaker has a slight humm. Any ideas on how to approach this problem? The tubes in the receiver section sit on a metal cannister of some sort.. Thanks. Dave