[time-nuts] DIY VNA design

Dr. David Kirkby (Kirkby Microwave Ltd) drkirkby at kirkbymicrowave.co.uk
Mon Aug 22 11:16:16 EDT 2016

On 22 August 2016 at 02:51, bownes <bownes at gmail.com> wrote:

> Comment inline
> > On Aug 21, 2016, at 18:59, Dr. David Kirkby (Kirkby Microwave Ltd) <
> drkirkby at kirkbymicrowave.co.uk> wrote:
> >
> > I am not convinced that this is time-nuts related,  although I am sure
> many
> > time-nuts either have a VNA or would like one. Such a project needs its
> own
> > forum.
> >
> VNWA at yahoogroups.com would be the place.

I doubt it would be, although one should ask Tom Baier. I don't suppose he
would mind some discussion, but the topic of VNA design is so large and
complex that it could generate a huge volume of messages, which are way
outside the scope of the VNWA group.

I do know of another possible reason he might be a bit reluctant too. I
made a post on there once about the fact I had measured the N connector on
a brand new competitive product (RigExpert AA-600) and found it was out of
spec - photos at


That resulted in the manufacturer of the RigExpert contacting Tom, as they
were unhappy about my comments. (Strangely they never contacted me!) I
received a phone call from Jan, the UK distributor about it. Basically they
did not want to get into a war with other companies like RigExpert. I can
see that discussions about VNAs in general could lead to discussions
comparing products.

In some ways it would be good if there was a forum for VNAs, and similar
instruments, which is not tied to any particular manufacturer. I'm not
aware of any. There's the HP/Yahoo list, VNWA and there's the Keysight
forums. Those are all specific to one manufacturer.

There are a number of techniques for measuring impedance, and the VNA is
just one of them. Keysight have no forums for LCR meters or impedance
analyzers, despite they sell the things.

> The intersection of HP equipment && Time-Nuts && VNWA mailing lists is >>
> 1 :)
Yes, very true. I'm certainly one of them, but as you say, it would be >>

Dr. David Kirkby Ph.D CEng MIET
Kirkby Microwave Ltd
Registered office: Stokes Hall Lodge, Burnham Rd, Althorne, Essex, CM3 6DT,
Registered in England and Wales, company number 08914892.
Tel: 07910 441670 / +44 7910 441670 (0900 to 2100 GMT only please)

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