Yes. About 7 years ago, I bought a VNWA3E, designed by German EE prof
DG8SAQ, built and sold by some hams in the UK. It runs on Tom's firmware
and Windoze software, powered via the USB port that feeds data to the
computer and controls the unit. It has an excellent TDR function -- you
perform a wide frequency sweep, which it post-processes to perform an
inverse FFT, yielding the TDR. Once the sweep has been made, it remains
in memory, and five different windowing functions can be applied to
yield the most informative view of the measurement. I recently used it
to diagnose issues with RX antennas that occur annually with storms
during what Californians laughingly call "winter." (All of our rainfall
occurs between October and May.)
Tom's software also includes very useful and versatile math functions
that can be applied to traditional VNA data, and can be set to compute
and display multiple data sets from each measurement. When tuning
filters, for example, it can display the filter response as gain, return
loss, and SWR, and each plot can be scaled as desired.
I paid about $700 delivered to my door around 2013; thanks to Brexit,
it's closer to $600. Build quality is excellent, and both Tom and the
mfr read a support email reflector daily, responding as needed to
issues. It's like the Elecraft reflector, with some very smart people,
but with a lot less traffic.
73, Jim K9YC
On 12/2/2020 8:26 AM, donovanf@erols.com wrote:
Its not that time consuming with modern, inexpensive tools like TDRs,
VNAs and antenna analyzers. It costs much less to purchase all three
than even the least expensive radio.
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