Emerson model 25 restoration

[charokeeroad]

I've drawn out most of the schematic. Quite a job for a little radio. None of the tube pins are numbered on the tubes or socket although I did find a way of locating the plate pin and the filaments. This set is the same as the 25A with the exception of having the seven pin jack wired in at various location to provide the optional power from batteries.

I think what I'll do is just replace the paper caps and return the set to it's schematic designated components and see if it works. I'm guessing that no one was able to find a schematic with the jack.

[dieseljeep]

Originally Posted by charokeeroad

I've drawn out most of the schematic. Quite a job for a little radio. None of the tube pins are numbered on the tubes or socket although I did find a way of locating the plate pin and the filaments. This set is the same as the 25A with the exception of having the seven pin jack wired in at various location to provide the optional power from batteries.

I think what I'll do is just replace the paper caps and return the set to it's schematic designated components and see if it works. I'm guessing that no one was able to find a schematic with the jack.

It was my thought to just disregard the external power socket. The 25A print should be close enough to troubleshoot. That radio is a real early design, using the oldest style resistors and capacitors.
The new 8 mfd caps on either side of the choke are fine as-is. I would get rid of that old rectangular box capacitor shown in the lower right corner of the first picture and install newer type components.
It's obvious someone changed the circuitry in the past, subsituting a power resistor for the original line cord resistor.