Thread Rating:
  • 0 Vote(s) - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5

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



Users browsing this thread: 2 Guest(s)
[-]
Recent Posts
Predicta Repairs Locally in So. Cal.?
I get that there seems to be less & less who are capable & knowledgeable to play with the vintage TV's. The gen...1962300 — 10:32 AM
Predicta Repairs Locally in So. Cal.?
Considerable TV data is stored on World Radio History. ChasChas — 03:33 PM
Model 41-295 rectifier tube 5Z3 vs 80
The 80 and 5Z3 are both full-wave rectifiers, and interchangable. The difference is the current draw and output. The 5...GarySP — 11:15 AM
Philco 37-116 toner
I will say i have sprayed over the Maguire's with no problem so there must not be any silicones etc in it Billpoulsbobill — 10:29 AM
Model 41-295 rectifier tube 5Z3 vs 80
I would the 80 less strain on power transformervinzer — 10:02 AM
Predicta Repairs Locally in So. Cal.?
Saddly, a lot of the techs knowledgable on these older sets are passing away, having health issues and simply aging. The...TV MAN — 08:42 AM
462ron
Thanks everyone for your responses and links to articles and products. A lot to ponder here. It will probably be a few w...462ron — 07:54 AM
Model 41-295 rectifier tube 5Z3 vs 80
If the 5Z3 and filters look original, I'd say stay with those components and values.The discrepancy may be the result of...Brad Winder — 06:47 AM
Model 41-295 rectifier tube 5Z3 vs 80
Restoring a 41-295.  Every schematic I've seen has an 80 rectifier tube and the electrolytics in the pi filter are 18uF ...FredM — 04:30 AM
Philco 37-116 toner
This may be irrelevant for different wood finishes from even longer ago, but maybe useful to research. Back in 1988 a...murrayatuptown — 01:53 AM

[-]
Who's Online
There are currently 1939 online users. [Complete List]
» 3 Member(s) | 1936 Guest(s)
AvatarAvatarAvatar

>