[time-nuts] HP8720C manuals?

[David Kirkby]

On 17 October 2012 20:35, Jim Lux <jimlux at earthlink.net> wrote:
> I just found an old 8720C at work, and I was thinking of pressing it into
> service to do some experiments with measuring changes in receiver filters
> and antenna match over temperature.  (Since I don't have to pay rental on
> it, it can just sit in the corner with the temp chamber and I can slap those
> GPS and S-band filters in there and fool with it, sort of in the background.
> ANswer all those questions about "just how much timing uncertainty is due to
> the filters" with some empirical data)
>
> I'm not looking for a big project, and I don't know how hard or easy it is
> to pull data out of the beast via GPIB. The problem is that I don't have the
> programming manual, and Agilent doesn't have it on their site. Nor is it on
> BAMA, etc.

If you can't find the manual under the 8720C, look under the 8720D. I
know there's one there for that, as I have downloaded it. If all else
fails, I can email it to you.

Also, take a look here:

http://na.tm.agilent.com/8720/programming.htm

where you can find the C examples of programming the instrument,
wheras there's only BASIC ones in the manual.

Another place to get information, is asking on the Agilent VNA forums.

http://www.home.agilent.com/owc_discussions/category.jspa?categoryID=32

There are several, one of which is devoted to programming.

http://www.home.agilent.com/owc_discussions/forum.jspa?forumID=73

I'm just in the process of writing  some code to drag data off the
8720D. It's written for the National Instruments GP-IB board, and Ive
only compiled it under Solaris, though I expect it would compile under
Linux with no problem. It uses the standard

$ ./configure
$ make

then

$ cd src
$ ./vna --touchstone-log-amplitude-angle --s11 --s21 15

will read S11 and S21 from the VNA at GP-IB address 15.

The first column is frequency, the next two are for S11, the next two
columns are for S21, the next for S21 and finally S22. (Actually, S12
and S21 might be in a different order. I'm not sure).

It is not in any finished state though. But if you want it, I just
stuck it here:

http://boxen.math.washington.edu/home/kirkby/vna-0.05.tar.gz

In it's present state, it can drag data off and saves in CSV format.
Actually, I'm aiming to get it in Touchstone (.s2p) format, which is
not much different. Excel or similar can reach a Touchstone file
without problems. The advantages of that, over a straight CSV file is
that some RF software can read that file format.

Dave, G8WRB