12-01-2007, 09:27 AM
Got my 2nd model 20 working somewhat but volume is a bit low. Ok lets
look at the plate voltages on the two 71's. Yep, there it is...no voltage on one of the plates.
Bad output transformer ? Wait a second, why is there only three wires on this speaker plug ?
Did some checking and from the tech
section on this great site I find "The Speaker Problem in early Philco
Cathedrals ". With this info and my Fluke 23 I find that I've got
445 ohms on the output trans primary side. Now couple this with the only 3
wires from plug I'm wondering is it possible. Do I have a model 70 speaker
with a model 20 chassis ? Anyone have a model 20 spkr they want to trade for a model 70 ?
look at the plate voltages on the two 71's. Yep, there it is...no voltage on one of the plates.
Bad output transformer ? Wait a second, why is there only three wires on this speaker plug ?
Did some checking and from the tech
section on this great site I find "The Speaker Problem in early Philco
Cathedrals ". With this info and my Fluke 23 I find that I've got
445 ohms on the output trans primary side. Now couple this with the only 3
wires from plug I'm wondering is it possible. Do I have a model 70 speaker
with a model 20 chassis ? Anyone have a model 20 spkr they want to trade for a model 70 ?
Danny
