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Philco 70 Cathedral
#23

+1 Brenda.

Yup would over couple the signal thus broadening the width of the rf amplifier stage. Not a great idea.

Think of it like this. You have a very nice high end hifi set and between the tuner and amp there's an equalizer. You set the eq to a level frequency across not boosting or cutting the audio range. This is like your ant coil stock from the factory. Rewinding the primary over the secondary or very close to it is like readjusting the knobs on the eq. It's going to make some frequencies more predominant than others. No it's not going to cause it to pickup stations in the wrong places on the dial. Just the rf amp circuit don't be working @ it's full efficiency.

Rewinding the bobbin is not particularly difficult. Remove the ant coil from the chassis. Nip off one or both of the tops of the slots on the coil. Remove the two wires. The original winding is 49 ohms so if you were to use 40ga wire it would take 49'. You can sort it for 38ga it will be a little longer. I don't remember if you can remove the winding without grinding off the rivet in the center. If it's brass use a small brass screw to replace it. Brass changes the inductance slightly vs steel. You can scramble wind it doesn't have to be a honeycomb or super neat. The phasing doesn't matter either (direction or which wire connect to which terminal). You can remount the two coils back together again with a couple of dabs of hot glue @ to top of the slots.

Remember by 1932 or so Philco was in the musical instrument business.

Have Fun!

When my pals were reading comic books
I was down in the basement in my dad's
workshop. Perusing his Sam's Photofoacts
Vol 1-50 admiring the old set and trying to
figure out what all those squiggly meant.
Circa 1966
Now I think I've got!

Terry


Messages In This Thread
Philco 70 Cathedral - by 462ron - 02-10-2021, 02:46 PM
RE: Philco 70 Cathedral - by Radioroslyn - 02-10-2021, 03:17 PM
RE: Philco 70 Cathedral - by 462ron - 02-10-2021, 11:12 PM
RE: Philco 70 Cathedral - by 462ron - 02-24-2021, 02:56 PM
RE: Philco 70 Cathedral - by patrician56 - 02-24-2021, 04:48 PM
RE: Philco 70 Cathedral - by patrician56 - 02-24-2021, 04:50 PM
RE: Philco 70 Cathedral - by Radioroslyn - 02-24-2021, 07:34 PM
RE: Philco 70 Cathedral - by 462ron - 02-25-2021, 07:16 AM
RE: Philco 70 Cathedral - by Radioroslyn - 02-25-2021, 08:56 AM
RE: Philco 70 Cathedral - by 462ron - 02-25-2021, 09:05 AM
RE: Philco 70 Cathedral - by Steve Davis - 02-25-2021, 09:22 AM
RE: Philco 70 Cathedral - by 462ron - 02-25-2021, 11:10 AM
RE: Philco 70 Cathedral - by 462ron - 04-12-2021, 01:49 PM
RE: Philco 70 Cathedral - by rfeenstra - 04-12-2021, 03:38 PM
RE: Philco 70 Cathedral - by 462ron - 04-12-2021, 05:15 PM
RE: Philco 70 Cathedral - by 462ron - 05-25-2021, 03:26 PM
RE: Philco 70 Cathedral - by Paul Philco322 - 05-25-2021, 04:03 PM
RE: Philco 70 Cathedral - by Ron Ramirez - 05-25-2021, 04:06 PM
RE: Philco 70 Cathedral - by 462ron - 05-25-2021, 05:11 PM
RE: Philco 70 Cathedral - by Ron Ramirez - 05-25-2021, 10:00 PM
RE: Philco 70 Cathedral - by BrendaAnnD - 05-26-2021, 01:19 AM
RE: Philco 70 Cathedral - by 462ron - 05-26-2021, 06:55 AM
RE: Philco 70 Cathedral - by Radioroslyn - 05-26-2021, 07:26 AM
RE: Philco 70 Cathedral - by Radioroslyn - 05-26-2021, 09:10 AM
RE: Philco 70 Cathedral - by 462ron - 05-26-2021, 11:31 AM



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