[time-nuts] VNA design

Richard (Rick) Karlquist richard at karlquist.com
Mon Jun 2 17:36:09 EDT 2014

On 6/2/2014 12:41 PM, Brooke Clarke wrote:
> Hi:
> I started with the HP 8410 and added an external computer.
> Since it can be used manually I think it's an excellent way to learn
> about VNAs.
> http://www.prc68.com/I/MWTE.shtml#NA

For my last 8 years at Agilent before retiring in March, I
was doing advanced R&D on network analyzers.  The newer
guys coming up didn't have an intuitive understanding of
network analyzer architectures like I did. I
started using the 8410 back in 1973 before I even worked
for HP.  Because of the modular design, it was like a
teaching tool that forced you to understand what was
going on.  When I mentored the young guys, I would
explain to them a lot of principles based on the 8410.
Modern network analyzers are too "automatic".
The 8410 puts modern VNA's into perspective.  BTW, I used
to sit next to Dick Lee, who was a member of the 8410
design team in 1963 at the dawn of the golden age of
microwave instruments based on YIG tuned oscillators
and step recovery diode samplers.

As you noted, the architecture was built around the YIG tuned oscillator 
and certain things were done that way they were because of that.

Rick Karlquist N6RK

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