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[TCML] Re: Finally finalizing my 304er VTTC

Hi all,

I have made measurements with my new device.
My device is a NanoVNA-F Vector Network Analyzer.

This is nice a small compact device, but not too small to use. It has a
decent screen size that is very readable and usable for the touch screen
functions by your finger. It also has a very decent capacity battery.

The reason for the extra comments, is that I also have, before I bought
this one, I purchased the original NanoVNA. (The "F" was not out yet.) Now
this one is much smaller and thinner. The screen text is hard to read.
Touch screen hard to use by finger. Stylus is nearly required. Battery life
not great, which is no surprise, since so small and thin, just no room for
a decent battery. That said, it does work. When I saw the "F" version come
out, I purchased this and what a great improvement and pleased.
The original while neat that small, it is just not that realistic in my

I have not kept track of these "Nano's" recently, so there are probably new
models and improvements.

These are very reasonably priced for what I feel you are getting.
As some may know...the real bench top/rack VNA 's are out of reach for
normal people. Can get extremely expensive.

While I know this will never be as accurate as the "real ones", I feel
these are plenty accurate enough for us coilers, and others in the several
other uses possible.

But I will also hazard to say, this is probably more accurate than my
recent secondary measurement with my function generator, scope, and LED's.
Again while still plenty accurate for our uses, it still is pretty tough to
adjust for the final 1000's as LED's intensity differences harder to see
now. And the hanging scope probe trace to help "see", "wavers" around some,
so a little bit of guessing here.

The screenshot pictures of my results are after I have narrowed down the
start and stop frequencies, to "zoom" in and get a better look at the
resonant frequency. It is really nice to be able to "see" this here.

I am still learning things about this device, but I would say I got decent
results here in comparison to my original and recent measurements of this

I have some more thoughts on this secondary buckling damage. The buckling
of wire is under quite a bit of tension. I would have thought, the wire
insulation was compromised in some areas, causing some shorting, but this
seems not the case.
But under these test conditions, nothing has really changed with my
function/scope/LED method because the what I call "visual" error in this
method in the slight frequency difference.

I have found the main culprit for the buckling. The winding height was
originally 13 3/4. It is now 13 5/8 measured just before I stripped the
wire off. The ripples that I can see inside, I now realize is bulges from
the tube form shrinking in height.

I have taken a couple of pictures of the bare form. I was hoping to see
something on the outside, but I can not see much at all. And I took another
of the inside...sorry this is hard to take this picture...

So I have satisfied some of my curiosities and hope maybe some find this
interesting :^) or not :-D

Pictures link of measurement result and form.


I have a new plan for the new secondary, and will post when I am ready and
have time...

Chris Reeland
Ladd Illinois USA

Sent from my Samsung Galaxy Tab® S

On Sun, Apr 25, 2021, 10:22 PM Chris Reeland <chrisreeland@xxxxxxxxx> wrote:

> Hi all,
> Okay, here is some measurements out of curiosity of the damaged secondary.
> There is really what I call no real changes here. Not completely sure what
> to make of this. While I was not expecting a huge difference, I was
> expecting some. Not what I consider "peanuts". Now under running conditions
> it could definitely be different. Will never know now, since I do not have
> any measurements of coil running with this damage. I do have some before
> this. I will let the few pictures speak for themselves. FSA on my note,
> stands for secondary Free Standing Alone (no toroid and break out point)
> for my starting frequency here on this coil.
> I'm going to be stripping this wire off. I was originally not planning
> this. But I want to better see where all the rippling is located on the
> whole form. Has me curious now. But first I am going to do some
> measurements with a new device of mine which I have had actually almost a
> year now and have not gotten around to using it. I will post details of it
> when I get there. I have to learn some on using it also.
> https://photos.app.goo.gl/anYAXJwMFtiTryQr6
> Chris Reeland
> Ladd Illinois USA
> Sent from my Samsung Galaxy Tab® S
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