03-27-2012, 06:19 PM
The original output transformer has a primary resistance of 700 ohms, plate to plate.
What is more important, however, is that this transformer needs to have a primary impedance of 12,400 ohms to match a 1.25 ohm impedance voice coil.
You can't measure impedance with your ohmmeter...but you'll need this info if/when you replace that audio output transformer. A Hammond 125D will work as a replacement; connect the voice coil to output terminals 4 and 5. It won't match exactly but will be very close.
What is more important, however, is that this transformer needs to have a primary impedance of 12,400 ohms to match a 1.25 ohm impedance voice coil.
You can't measure impedance with your ohmmeter...but you'll need this info if/when you replace that audio output transformer. A Hammond 125D will work as a replacement; connect the voice coil to output terminals 4 and 5. It won't match exactly but will be very close.
--
Ron Ramirez
Ferdinand IN
![[-]](https://philcoradio.com/phorum/images/bootbb/collapse.png "[-]")
