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
The list of my radio & TV collection!
Ok. Everything opens with a direct link. Yes. As Arran said, this is a transistor radio. It is a more expensive version ...RadioSvit — 03:07 PM
Electrolytic restuffing/internals
Gary I thought the same, but then isn't a hacksaw by definition is the one with fine teeth? >>A hacksaw is a...morzh — 03:01 PM
The list of my radio & TV collection!
Ah a KiJiJi seller! I've noticed that KiJiJi tends to be where all of the rejects from craigslist go, not that there ...Arran — 01:43 PM
Electrolytic restuffing/internals
When I'm lazy, I use a razor knife with a new blade. Nice smooth, even cut, minimal loss of material and no trimming or ...RodB — 01:39 PM
Electrolytic restuffing/internals
I still disagree with your sawing or cutting method. It is much easier in terms of the opening method and better in term...Vlad95 — 01:29 PM
Electrolytic restuffing/internals
For the question about the jagged hacksaw cut, the most common reason is too aggressive 'bite' of the saw blade. I use ...GarySP — 01:26 PM
Electrolytic restuffing/internals
Well I retire in about three years. My plan is to build a better workshop that has an area for these kinds of things. ...bridkarl — 01:14 PM
Electrolytic restuffing/internals
Ido remember you telling us about your health condition. Yes, a vise is a good thing to have. Many things I do I woul...morzh — 01:08 PM
The list of my radio & TV collection!
Strange, the second link works for me without problems. Try this direct link. Or try searching for "AKKORD DELUX ...Vlad95 — 01:08 PM
The list of my radio & TV collection!
Looks like Peter and I have the same idea.RodB — 11:37 AM

[-]
Who's Online
There are currently no members online.

>