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From what I read here the other day, believe TDR exists in some firmware
releases, but the person that developed that is breaking the terms of the
GPL and not releasing it.

I just wondered if anyone was working on actually producing TDR legally,
adhering to the GPL license conditions.

Dave
--
Dr. David Kirkby,
Kirkby Microwave Ltd,
drkirkby@...

Telephone 01621-680100./ +44 1621 680100

Registered in England & Wales.
Company number 08914892.
Registered office:
Stokes Hall Lodge,
Burnham Rd,
Althorne,
Chelmsford,
Essex,
CM3 6DT,
United Kingdom

Dave,
What was said about 150 posts back was that we don't need an actual TDR function - anyone can figure out the length using the Logmag function, the coax velocity factor and a calculator.
I've been following all the threads about this and I have not seen anyone mention there is a F/W version with TDR.

What was mentioned by me was a request to add a TDR function as there is more than enough flash available.
What is more realistic in the short term is for someone to write something Python to do this externally - maybe in NanovnaSharp? (hint hint)

Cheers,
Larry

Someone has developed a Python tool to do this, and I believe it looking into adding it to the f/w.

/ Gerry

Oh yeah, I forgot about that post.
The only issue is you need to read with VNA Sharp, then save, then run the saved file through the Python app.
It would be nice to just run the Nano directly from a python app, click a button and you've got the length. :-)

Larry

On Mon, 26 Aug 2019 at 12:55, Larry Rothman <ac293@...> wrote:

Dave,
What was said about 150 posts back was that we don't need an actual TDR
function - anyone can figure out the length using the Logmag function,

The TDR gives you a *lot* more than just length. See



You can’t assume anything about the velocity factor either - it’s far from
a constant, whereas with TDR you can measure an actual impedance - no need
to know the diameter of the coax or the relative permittivity.



Cheers,

Larry



--
Dr. David Kirkby,
Kirkby Microwave Ltd,
drkirkby@...

Telephone 01621-680100./ +44 1621 680100

Registered in England & Wales.
Company number 08914892.
Registered office:
Stokes Hall Lodge,
Burnham Rd,
Althorne,
Chelmsford,
Essex,
CM3 6DT,
United Kingdom

Agreed, but in the context of most of the users on this forum, TDR is more than likely to be used for length and fault finding.