velocity factor of black iron oxide ?

[spacecase0]

anyone know velocity factor of black iron oxide powder ?
I am trying to design something and can't seem to figure out how fast radio waves go through the iron oxide powder, like the kind you find in copy toner.
I know some of you have made your own transformer cores,
and hope someone already knows this answer.
I have searched the web for a few weeks now and just can't find the answer.
thinking about a frequency in the 146MHz range
but would be up for data for any frequency
seems like some of the ferrite cores might be similar, but not sure about that.
I just don't want to have to measure this for myself as I don't think I have the hardware to do it accurately.

[RAMSET]

been asking around

Have had suggestions on how to check this on the bench
however as you most likely know the variables would be or could be an issue [quality data or ? inaccurate ?

still asking ,its a cool question IMO and actually fits [the answer]
with some other ideas and potential experiments.

respectfully
Chet K

[mikrovolt]

Absorbing can be related to Suppressing (EMI). Making epoxy bead, T-37 toroid with silicon mold as inductor or inverse relation
as suppressor with bead cylinder shape and very small toroids for quantitative measurements.
After 100 Mhz a typical ferrite bead stops being inductive and starts being resistive (heat).
Making a T-37 toroid with silicon mold as inductor or inverse relation as suppressor with cylinder shape.
https://www.resinobsession.com/resin...n-resin-beads/
Testing ferrite beads is shown in the video, filtering a spectral line or one of the frequency bands.
https://youtu.be/IvmSNmnFMxA
Murata application manual.
https://www.murata.com/~/media/webre...ifil/c39e.ashx

Also link below that in the section subtitled "Short history of ferrites." the soft magnetics in the lab proved to be elusive.
I think that might be something like the frequency vs impedance chart for ferrite ceramic cores. Epoxy cores is an interesting subject.

https://palomar-engineers.com/ferrit...-mix-selection

[RAMSET]

perhaps helpful ?

Do you mean Fe3O4 ?

If yes, then it is a conductor, which means that it will exhibit a skin effect.
It also has a high magnetic permeability which exacerbates the skin effect.
All of this means that Fe3O4 will expel RF currents from its volume and does not support RF wave propagation beyond the near field.

Quick search for the zero-field resonance frequency of Fe3O4 in zero external magnetic field yields approximately 71MHz RF nuclear resonance frequency in this article:
https://www.researchgate.net/publica...es_by_57Fe_NMR
See Fig.4.
-------------------------------------------------------------

Chet

[spacecase0]

not sure how I missed any replies till now.
thank you for the replies, will take me a while to finish reading the one PDF, and even if the answer is not in there, it is good information, much that I have not seen before.

it is black even without the toner mixed in, so it is likely Fe3O4

there is sure a chance that it is to conductive and will not work.

after thinking about it a few weeks (not sure why I did not think of this right off), I am planning on setting up a small dipole antenna, then enclosing it in the iron oxide power. then checking for resonance.
I do have hardware to check for resonance from 1.6Mhz up to about 200MHz (grid dip meter, suppose to go to 250MHz, but it does not)
so if I do something like assume a velocity factor of 0.15 as a first try on resonance, then I might be able to get close enough to test it in air and inside the iron dust and see the change. If not, then I will use theoretical distance calculations for the free space test.
and also, I will also keep in mind open air resonance for the entire mass of iron oxide powder to see if I am just finding resonance of that.

the NMR resonance at 71-72MHz is something I had no idea of before. So seems like I either want it running at that frequency, or not near it at all. Testing should tell me what one is best.

[RAMSET]

you practice Brutal honesty ...

anything I can do to assist ....I know bench time is hard to come by
and making the most of that time is crucial.
the info provided was from an open source friend of ours .

he is helping to model an open source iron NMR experiment to hunt for anomalies or excess energy.

I know you are searching other paths too...very interesting paths.
perhaps a brief explanation of your goal here [this thread] and the test protocol ?
we have some very experienced fellows with eons of experience
and like yourself quite dedicated !

you never know ....they may have some good suggestions ...
IMO fellows like yourself are worth their weight in gold...and should get all the help the open source community can offer.

respectfully
Chet

[spacecase0]

go edit your last message and remove your email address
you might get way to much spam if you do not
I also sent you an email.
google often does not like me sending messages to new people, so go look in your "all mail" folder if you don't see it.

long ago lots of scientists looked at NMR for free energy, Telsa was one of them. makes me wonder what happened to that idea.
the only history I can find on that is that everyone just quit talking about it all at once.

what I want with the velocity factor of the iron oxide is the same thing I have been trying to do for a while now,
I want to set up an asymmetrical rotating magnetic field.
air core versions I have tried seem to have at least one order of magnitude to little strength.
and when you start looking at the end result of magnitude times the speed of a spinning magnetic field, there is a trade off, actually a few of them.
the higher the frequency, the more costly the transistors.
the advantage there is smaller wavelength, so you can build all the hardware smaller and potentially higher power density.
then I already have enough IGBTs that are rated for 2KW and would deal with lower frequencies just fine. and if I break with theories for a bit and believe that the hull of at least some of the crashed UFOs are made from a magnesium ferrite, then it is quite likely that they run at a frequency of less than 1MHz.
so, I was hoping that I could use things I already had, drop the frequency, use a magnetic core, and put lots more power into the test setup. but without resonance of any sort, I am still about 100 times to little power (even with 4KW in).
I have fast capacitors that have a Q of about 100 (if my memory works, but no spec sheets are available), so if I design it all correct, it should work. but I better know what my core material is going to do or I might burn out $400 worth of transistors in a moment. or even worse, I turn up the power slowly and it is clear that something is just not going to work, but I would not know what is wrong.

[RAMSET]

good stuff...and yes NMR and similar

I have attached one paper which shows some of the direction being discussed
for open source NMR experiments with FE [just to start with]

keep in mind the groups goal is making the seemingly daunting task of experimenting with NMR or NAR ...and obtaining quality Data ..
much more user friendly .

the document is to be used solely as a format for getting appropriate samples to the bench.
we are exploring using Argon as a "filler" to prevent oxidation of the purest iron particles we can get.
placed in a sealed glass tube ,and then annealed for a day or so at 400C

and when done ready for bench testing

I did see your Laser Topic ....will be getting more info for "mentioned" experiments there.

to be clear there are no boundaries for what needs testing with NMR..NAR
and its interactions with.....whatever .
what is mostly needed is a good starting point for frame of reference .

respectfully
Chet K

[spacecase0]

I ran the test today and looked for velocity factors from almost zero to a little over 0.2 and found nothing.

clearly if it is to conductive the velocity factor will be almost one (like it is for copper).
so I leave this post on the computer while I run the next test.

these following are full loop antennas and not a dipole like the first one.

initial numbers get me 0.529
but that resonance was at 71.3Mhz...
the number is close enough to 1/2 to make me wonder if it was an actual reading of one, and I was just on a harmonic.

so I did it again with another length of wire inside, and found resonance at 92.3MHz (so not a special number)
and that number was 0.254
yet again, the number is close enough to another harmonic (this time 1/4) to make me wonder if it was an actual reading of one, and I was just on a harmonic.

I then tested 2 other lengths of wire and could not find resonance at all. the sun is setting, so my lab is now getting dark, but not sure what else I would try now anyway.

so if I had to guess now,
I would say that the velocity factor is likely 1.
And that is what you see for a conductor.