On Wed, 16 Oct 2019 at 08:30, <erik@...> wrote:
The nanoVNA is a full three mixer three receiver VNA without the switch to
reverse the signal path
Em,
in that case it would suggest a 4-receiver VNA may be economic if the
switch was external and purchased by the user if they want it.
That¡¯s what the VNWA 3E - it provides the signal, but not the actual switch.
It¡¯s often possible to pick up HP/Agilent 18 GHz SPDT mechanical relays
for a modest amount of money in small quantities. I have 10 here I picked
up very cheaply. I believe there¡¯s a way of configuring just two, which
enables one to reverse the direction of the signal. There¡¯s information
somewhere on the VNWA resources how to do this, without actually needing a
more specialised relay designed for that purpose.
I would see the major advantage of 4-receivers to be the ability to
perform *unknown
thru calibration*. That is incredibly useful, as you can perform a
calibration with two male cables, ignoring the properties of the thru. The
adapter can even be SMA to N, or even a waveguide to coaxial.
The NanoVNA is an amazing bit of kit for the money.
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
