@dllabarre

I apologize to ask but what kind of inductance meter (make/type) do you use that has a higher than 200Henry measuring range?

Because I suspect there is a wrongly calibrated meter... 
I base this on seeing the photo of your toroidal coil and simply I am not aware of any toroidal core taken out from mass produced monitors etc that would have an extremely high permeability which would give Henry inductances with those number of turns.
In the past I also took some measurements on such bifilar coils either with toroidal or closed E cores, both in the some ten to some hundred uH and to some ten mH ranges for any one of the coils.  And when I also connected the two coils in series as you did (i.e. measured between the beginning of the first coil and the end of the second coil, the other end and beginning was joined of course and left floating). 
What I found was that such closely coupled bifilar coils gave a resultant inductance of roughly the four times of any single coil, so in case one coil from a bifilar has 26mH, then the two coils in series (joined as described) gave around 100mH or so (but definitely not in the Henry range).

Respectfully,
Gyula

Quote from: dllabarre on September 01, 2009, 12:25:12 AM
Can some one with an inductance meter and a bifilar toroid try this for me?
I was measuring some of the toroids I have taken out of devices like TVs and computer power supplies when I came across something strange.
First I measured the inductance when connected to the beginning and end of the first wire and got 36.8uH.  Then the beginning and end of the second wire and got 36.6uH. 
I'm always for trying something really strange just to see what happens.
I then measured connected to the beginning of the first and to the end of the second wire and got 239.1H.... Yes Henries.  Not mH or uH but Henries.  I don't know if I could actually connect this toroid like this in a circuit and have it work this way but it would be really cool if it did.  This does not work with ferrite core rods.  I tried.
Here's the toroid I measured:

gyulasun
Thank you for the links.  However, the pics there showed the inductors to have three legs and mine only have two.  Does that mean mine are just a smaller version, or for a different purpose?  I know if I keep searching the net I will eventually come across the correct picture showing these same items I have described.  Hopefully I will also learn how to use them. 

DonL,
For some reason when you posted your picture of the toroid, it covered the words so I was not able to read what you were saying.  I did eventually get to read it when gyulasun posted your quote, though.  Are you using a laptop?  Just wondering why the picture covered the words as I have seen that once before in one of these forums.

Quote from: gyulasun on September 01, 2009, 05:23:56 AM
@dllabarre

I apologize to ask but what kind of inductance meter (make/type) do you use that has a higher than 200Henry measuring range?

And when I also connected the two coils in series as you did (i.e. measured between the beginning of the first coil and the end of the second coil, the other end and beginning was joined of course and left floating). 
What I found was that such closely coupled bifilar coils gave a resultant inductance of roughly the four times of any single coil, so in case one coil from a bifilar has 26mH, then the two coils in series (joined as described) gave around 100mH or so (but definitely not in the Henry range).

Respectfully,
Gyula

EXTECH 380193 - it works fine - i've double checked it with caps, resistors and inductors.

Yes I agree with you when I connected the bifilar wires together and measured them. 
But I'm doing something that is very unorthodox here.
Do NOT connect the end of wire 1 to the beginning of wire 2.  Just connect your meter to the beginning of wire 1 and to the end of wire 2.  This shouldn't work well because the 2 wires are not connected but just try it.

DonL

@protonmom

I'm not using a laptop.
I've never seen the pictures cover the words.
Have you seen this with other postings or just mine?
Maybe I'm doing something different then everyone else.

Since last week, when I try to post, the posting window acts very strange jumping from the bottom to the top so I can't see what I'm typing unless I keep scrolling the input window down.  Quit annoying but it is the way it is.

DonL

Quote from: t3t4 on September 01, 2009, 02:31:47 AM
@ Don,

What I would like to know is this: Why are you and jeanna having difficulty duplicating my results?

Thanks,
t3t4

I haven't used your circuit or any circuit yet.  I just use a capacitor connected between the aerial and a ground rod.  I'm focusing on what aerial is the best that is also cheap and easy to construct.
I'm moving to "wire suspended in the air" type of aerials. 

DonL