Welcome Guest! Be sure you know and follow the Phorum Rules before posting. Thank you and Enjoy! (January 12) x

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

Replacement for .7 to 1 interstage transformer
#1

Had a similar thread, but it wasn’t as specific as this, and therefore got lost. Anyone know a good replacement for this interstage transformer? Has a turns ratio of .7 to 1. It’s in a Sparton 28.

[Image: https://i.imgur.com/lNO85AP.jpg]
#2

It can not be .7 to 1.
Just by the sheer DC resistance, even if accounted for the wire gauge, 700 Ohm to 1 Ohm means huge difference in the number of turns.

People who do not drink, do not smoke, do not eat red meat will one day feel really stupid lying there and dying from nothing.
#3

Morzh,

Look at the schematic. Primary at 3580Ω, secondary center-tapped at 2985Ω (or 5970Ω total secondary). equals a turns ratio of actually .599 to one, but close enough to the rated value of .7 to 1. Am I missing something here?
#4

Morzh,

Oh, I see. Your're looking at the output transformer. I'm referring to the input or interstage transformer.
#5

Oh..yes I was looking at the output.

38-116 has a similar one.
Lets' see if Tubes and More has something.
Nope. They have 1:2 and 1:3. Can't see that ratio around.
Maybe someone else can.

People who do not drink, do not smoke, do not eat red meat will one day feel really stupid lying there and dying from nothing.
#6

I found a 1:1.5 but that was the lowest. Did find a 1:1 but was discontinued.

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
#7

1:1.5 and 0.7 to 1 are close enough.

People who do not drink, do not smoke, do not eat red meat will one day feel really stupid lying there and dying from nothing.
#8

It's a Hammond 124D

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
#9

Great! Thanks Terry. I'll get a 124D and give it a shot.

Pat




Users browsing this thread: 1 Guest(s)
[-]
Recent Posts
The list of my radio & TV collection!
Magical chords of forgotten melodies, old nostalgic music on an old radio... Saturday night blues on the Mid-Waves on an...RadioSvit — 12:20 PM
Philco 42-345 Restoration/Repair
Thank you MrFixr55 the issue with this radio is that the internal coil antenna is missing and there was a wire in its pl...osanders0311 — 11:34 AM
Philco 610B oscillator wiring
Regarding the oscillator circuit which is comprised of the 6A7's cathode, control grid, and screen grid. These elements ...Radioroslyn — 10:33 AM
Philco 42-345 Restoration/Repair
Hi OSanders, First off, welcome to the Philco Phorum where Phine Phamily-Phriendly Pholks Phull of Philco Phacts and P...MrFixr55 — 08:41 AM
Philco 42-345 Restoration/Repair
Today I've been reading through the site trying to learn more about this radio. I also soldered the lose power cord cabl...osanders0311 — 08:24 PM
Philco 610B oscillator wiring
Thanks David! I do have that same later prodution model 610 schematic. I've also studied the Philco service bulletins fo...Tubester — 08:12 PM
Philco 610B oscillator wiring
Some info from Beitmans says late production. David   David — 06:06 PM
Restoring Philco 96
Oh wow! Just found this thread.  Brings me back to early days on this phorum.  I did a 96 back in 2017.  Thread here: ...rfeenstra — 06:05 PM
Philco 610B oscillator wiring
Thanks for the replies. It's not the really the hum that I am after. Just trying to understand why only the shortwave ba...Tubester — 04:01 PM
Restoring Philco 96
70 and 90 are Superhets, but at least the 2x45 model of 90 uses the Plate detector (and so does 70). Also the Atwaters,...morzh — 03:28 PM

[-]
Who's Online
There are currently 3613 online users. [Complete List]
» 1 Member(s) | 3612 Guest(s)
Avatar

>