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118X electrical overhaul
#11

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?


Messages In This Thread
118X electrical overhaul - by Davros - 12-29-2016, 10:24 PM
RE: 118X electrical overhaul - by klondike98 - 12-29-2016, 11:54 PM
RE: 118X electrical overhaul - by morzh - 12-30-2016, 12:12 AM
RE: 118X electrical overhaul - by Radioroslyn - 12-30-2016, 02:02 AM
RE: 118X electrical overhaul - by Davros - 12-30-2016, 02:03 PM
RE: 118X electrical overhaul - by morzh - 12-30-2016, 04:40 PM
RE: 118X electrical overhaul - by Davros - 12-30-2016, 07:41 PM
RE: 118X electrical overhaul - by morzh - 12-30-2016, 08:17 PM
RE: 118X electrical overhaul - by Davros - 01-01-2017, 05:09 PM
RE: 118X electrical overhaul - by morzh - 01-01-2017, 05:20 PM
RE: 118X electrical overhaul - by Davros - 01-01-2017, 10:40 PM
RE: 118X electrical overhaul - by morzh - 01-01-2017, 10:49 PM
RE: 118X electrical overhaul - by Radioroslyn - 01-01-2017, 11:10 PM
RE: 118X electrical overhaul - by Davros - 01-02-2017, 07:54 PM
RE: 118X electrical overhaul - by Davros - 01-02-2017, 09:18 PM
RE: 118X electrical overhaul - by Mondial - 01-02-2017, 10:17 PM
RE: 118X electrical overhaul - by morzh - 01-02-2017, 10:17 PM
RE: 118X electrical overhaul - by Davros - 07-17-2017, 05:26 PM
RE: 118X electrical overhaul - by morzh - 07-17-2017, 06:07 PM



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