Some of you folks probably have the TAPR VNA designed by N5EG that is sold by
TenTec (a nifty device, by the way, although it doesn't do well with
interfering signals.. its internal receiver is not narrow band)
I discovered when fooling with the beta software that the 1 meter
(theoretically 39.37") cable supplied with the VNA by TenTec is actually less
than 36" long. You get a 1m and a 3m cable, along with the short and load cal
standards, which are all used in the calibration process. Having the short
cable 90cm long instead of 100cm created a problem in the cal process. The
actual length isn't critical, but it needs to be over a certain length, and
90cm is a hair too short, at least with the beta software.
The cables are actually made by Cable Xperts (part number CXP058ASM1M) and it's
possible that it was accidentally mismarked, or that's within the manufacturing
tolerances, or they measure the 1 meter before trimming the coax to put the
connectors on or something.
Anyway, if you have one of these VNAs, you might want to check the length of
the cables. (my 3m cable is actually 3.07m long)
Jim, W6RMK
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