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I bought a FieldFox at some point and paid for the “vector voltmeter”
option. I was expecting a high impedance input, but it was not and I felt
it was a bit of a waste of money.

All this expensive option did was display something in a different way to
the usual way. But thinking about it, this feature does have use to the non
technical ham.

All this does is display the loss and phase of S11 at a single frequency in
big numbers. It’s designed for cutting things like coax for antennas.

Since links often break, I took a screenshot from my mobile phone.



It certainly would not be on my wishlist, but it might interest others.



--
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

The main feature of a Vector Voltmeter is that it can measure the amplitude and phase of an independent signal (one not generated by the VV itself). It can be useful for measuring embedded components. A simple VNA does not (generally) have that capability. External buffers can of course be added to the Fieldfox, to achieve the high impedance. Have to say I never really liked the Fieldfox, seemed a very clumsy instrument to me.

On Sun, 13 Oct 2019 at 11:06, <trevor.blake1@...> wrote:

The main feature of a Vector Voltmeter is that it can measure the
amplitude and phase of an independent signal (one not generated by the VV
itself). It can be useful for measuring embedded components. A simple VNA
does not (generally) have that capability. External buffers can of course
be added to the Fieldfox, to achieve the high impedance. Have to say I
never really liked the Fieldfox, seemed a very clumsy instrument to me.

I think the term “vector voltmeter” in the FieldFox is a bit deceiving,
given the hardware called vector voltmeters have been available for years -
I used one for my final year project as an undergraduate.

I don’t have much luck with FieldFoxs. The MTBF of those I have owned is
two weeks

* A factor reconditioned (CertiPrime) N9923A lasted a month. Before the
month was up I had found numerous firmware bugs.
* A used N9912A was DOA.

The DOA one was returned to the seller, who solid to an unsuspecting eBay
buyer.??

The capabilities of the cheapest in that range (N9912A) can’t even measure
the phase of S21.

Those gripes aside, I thought it was a well thought out instrument, and
pretty easy to use.

*When I finally get my NanoVNA boxed up, it will have some features no
FieldFox has. *

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