[TowerTalk] To get a truly balanced antenna feed

[Richard (Rick) Karlquist]

Yes, Jim the math is the sticky part.
However, it turns out that the way the
Keysight E5071C works, is that you go
to the Keysight site and download some
"Visual Basic" software, and install it
on your E5071C to make it do 4 port
measurements.  (There are also a bunch
of other "personalities" you can download).
This is all public information, although
I used to work there.

Possibly, this software is also the source code,
since Basic is not a compiled language.  Therefore,
you could reverse engineer it for your own use?
(Easy for me to say, I know zero about software).
Let us know if you get it working.

Rick N6RK


On 6/24/2016 1:07 PM, jimlux wrote:
>
> The math is probably the sticky part.  I started building a 4 port unit
> for phased arrays using the tentec VNA and some surplus coax relays, but
> the integration of the VNA software with the (relatively simple)
> software to switch the relays with the (not so simple) post processing
> software got to be overly complex.   The VNA software for most ham VNAs
> didn't lend itself to being "part" of an overall measurement system, so
> there was a lot of trying to fool it with reloading cal files for each
> relay configuration.
>
> I suspect that had I spend some substantial time on it, I could have
> done all the cal outside the VNA software, but that was also tricky.
>
> OTOH, measuring mutual Z among phased array elements is probably less
> challenging for a VNA than characterizing a balanced transformer.
> There's a reason they charge what they do for N-port analyzers.
>
>