[MrFixr55]

Hi Hamilton, 

First, the good news:
The readings between Pins 4 of the 2 output tubes (Control Grid)  and between pin 4 of one of the output tubes and the center tap of the interstage (driver) transformer are good.  The readings between pin 5 (cathode) of each tube and chassis are correct (these should be 0 Ohms).  The readings of 0.2 Ohm between pin 3 and 4 of each tube are normal.  If you inspect the socket, you should see the jumper.  

The bad news.  The readings between pin 2 of one output tube and pin 2 of the other are messed up!  They should be what I listed in my last post (around 350 Ohm).


Unfortunately, neither the schematic from the Philco Library nor the one from Nostalgia Air have pinouts for the speaker plug or wire color codes.

From your pictorial and your readings, and using your numbering in your pic of the speaker, I am fairly sure that the connections at the speaker are as follows:
Pin 1- Field Coil to B+ for rest of radio
Pin 2- B+ from Power Supply (Choke, 8.0uF Cap# 77) to center tap of output transformer primary and Field Coil
Pin 3- One leg of Output Transformer primary to one 42 plate and screen grid
Pin 4- Other leg of Output transformer primary to the other 42's plate and screen grid.

Now, these connections may or may not be correct (someone may have botched a repair but done a nice solder job years ago).

Ron or any other experts who worked on one of these, please jump in on the correct speaker pinouts.

Try this:
Unplug the speaker and read between pin 2 of one tube and pin 2 of the other.  The meter should indicate an "open" circuit, infinite resistance. (The meter will display a 1, just as if the probes are not connected to any device.  There may be a very high resistance reading for a second before going to open due to the capacitors between pin 2 of each tube and ground.  If not, check for a solder bridge somewhere, likely where the caps are soldered to the speaker connector.

Next check the speaker. Leaving the speaker plug unplugged, verify the following:
Between your #3 and #4 you should read approximately 350 Ohm
Between your pin 2 and your pin 3, and between your pin 2 and pin 4, you should read somewhere around 175 ohm. The readings between pins 2 and 3 and between pins 2 and 4 will be different but when added together, will equal the readings between pin 3 and pin 4.
Between pin 1 and 2, you should read somewhere around 1140 Ohm.
When looking at your DVM, ensure that it is reading Ohm and not KOhm. Most DVMs are "auto-ranging".

Keep us posted. I hope that we can figure this out, as it is not good for the one 42.