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

Philco 18 oscillator coil rewind
#1

Hello all, I have an open secondary winding on my oscillator coil, item #16 in the parts list with a secondary resistance value of 3.4 ohms. I counted 16 turns of original transformer or magnet wire, which is about the size of a human hair. The smallest transformer wire I have is 33 AWG. When I restring the secondary coil with 16 turns as original, I am measuring 1.2 ohms. So, what is more important here, the resistance value (which I think they used as a measuring reference) or the inductive reactance which is how this coil is actually used? I know the number of turns affects the inductance, but I get the wrong value when checked with a vom. Thoughts?? Thanks!!
#2

Inductance trumps the resistance. The resistance is going to be different as your wire size is larger. If you don't have enough turns it won't oscillate at the low end of the band. Coil is used to couple feedback from the cathode to the grid and is not in a resonant circuit.

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
#3

So should I go with my rewound coil with 16 turns measuring 1.2 ohms?? Thanks
#4

Forget ohms. Go for the turns. Also if you don't have the proper wire (often gauge 42) I recommend you buy a spool, with 30-s radios comes handy more often than I'd like to see it.
If the coil is not a part of the resonant tank the turns is the only thing that matter.
If it were, than everything would matter, turns, length of winding, thickness etc.

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.
#5

Thanks for the help gents!!!




Users browsing this thread: 1 Guest(s)
[-]
Recent Posts
Philco model 60
This is my thread on 60 from 2016. I had to rewind the osc coil, and I actually counted the turns and then rewound i...morzh — 03:34 PM
Philco model 60
Yes, Mark belongs to the same Michigan Antique Radio Club that I do. I suspect that the oscillator coil is in need of a ...Radios1340 — 03:10 PM
A Marconi model 86
Yeah. I am dreading the thought of what to do with all my consoles when I will no longer be able to move them around. I...morzh — 02:51 PM
1947 Silvertone 7086 Wire Recorder/Phono/Radio on YouTube
Cool gadget, Buzz. I took me a couple of second to undestand that that oscillating thing makes the wire to spool correc...morzh — 02:50 PM
A Marconi model 86
My back hurts already, you could build a house with all the wood. PaulPaul Philco322 — 02:49 PM
1947 Silvertone 7086 Wire Recorder/Phono/Radio on YouTube
Part 4 of this series now uploaded link below to anyone interested Buzz — 02:39 PM
Philco model 60
Welcome to the Phorum, Radios1340!  The oscillator coil on the 60 is a common culprit.  I just bought a 60B (June 1934) ...GarySP — 02:33 PM
Philco model 60
Yes, standard alignment procedure. I can get the minuscule tone to vary when adjusting the trimmers. But you almost have...Radios1340 — 01:40 PM
A Marconi model 86
An imposing-looking radio, for sure.morzh — 12:43 PM
Philco model 60
Model 60 struck again :lol: Welcome to the Phorum! Above is the article on Model 60. Could be of some use. Now...morzh — 12:38 PM

[-]
Who's Online
There are currently 6751 online users. [Complete List]
» 1 Member(s) | 6750 Guest(s)
Avatar

>