01-01-2017, 10:40 PM
OK, so the Field Coil is the terminals that are reading 1100, and the OPT is shot. (Verified)
Looking into the speaker, it looks like I'm in for a rebuild, as the inside is in bad shape, with the wires are pulled out from the speaker cone.
I would like to replace the speaker with a PM speaker. As I understand it, I can use the Field coil from the original speaker and not have to mess with resistors and chokes. Then I will replace the OPT with the following OPT https://www.tubesandmore.com/products/tr...15-w-80-ma
(I chose this OPT as it has a wide variety of impedance to choose from depending on the Taps used)
I can even get my B+ from the same side of the Field coil as I can see where its tapped into the original OPT
Then replace the 10.5" speaker.
I may even cut out a new speaker board, and place the original speaker in the void of the cabinet attached to the board. That way I can always revert back if needed.
I took the following info from another post, and I am putting it here for easy reference.
The audio output transformer is Philco Part No. 32-7078.
Secondary impedance = 1.25 ohms
Primary impedance = 5,580 ohms
Primary D.C. resistance of the 32-7078 output transformer is 310 ohms (Philco Service Bulletin 180B)
Any issues with this plan?
Looking into the speaker, it looks like I'm in for a rebuild, as the inside is in bad shape, with the wires are pulled out from the speaker cone.
I would like to replace the speaker with a PM speaker. As I understand it, I can use the Field coil from the original speaker and not have to mess with resistors and chokes. Then I will replace the OPT with the following OPT https://www.tubesandmore.com/products/tr...15-w-80-ma
(I chose this OPT as it has a wide variety of impedance to choose from depending on the Taps used)
I can even get my B+ from the same side of the Field coil as I can see where its tapped into the original OPT
Then replace the 10.5" speaker.
I may even cut out a new speaker board, and place the original speaker in the void of the cabinet attached to the board. That way I can always revert back if needed.
I took the following info from another post, and I am putting it here for easy reference.
The audio output transformer is Philco Part No. 32-7078.
Secondary impedance = 1.25 ohms
Primary impedance = 5,580 ohms
Primary D.C. resistance of the 32-7078 output transformer is 310 ohms (Philco Service Bulletin 180B)
Any issues with this plan?