Summary for people like me.... IT DOESN'T MATTER.
73
Charles Harpole k4vud@hotmail.com
Well Charles,
if something was done and it was done wrong, then it would matter, as
the results would be invalid. The effect of the SMA to BNC adapter is
not accounted for, and depending on how the VNA was calibrated, could
cause significant errors. But Larry has done some other tests (not
mentioned), that indicates his results are valid.
There's a lot of people creating web pages, claiming all sorts of
wierd and wonderful things, but are seriously in error, but seem
believable to others. Here is one example
http://www.rason.org/Projects/collant/collant.htm
What's wrong with this site? Lets be specific here! Not just deal in
generalities.
73
Jim W7RY
but there are many other web pages like, especially on antennas, where
many hams write complete and utter rubbish, but it looks well
presented and believable.
Dave
Date: Thu, 14 Nov 2013 00:08:25 +0000
From: david.kirkby@onetel.net
CC: amps@contesting.com
Subject: Re: [Amps] All the recent UHF connector discussion
On 13 November 2013 22:45, Larry Benko <xxw0qe@comcast.net> wrote:
I had made some UHF connector measurements recently and this discussion
encouraged me to publish them.
If interested see
http://www.w0qe.com/Technical_Topics/uhf_connector_compensation.html
73,
Larry, W0QE
Larry,
I'm not a fan of UHF connectors, but your article was interesting, but
there are a few things I don't understand.
1) You don't describe how you calibrated the VNA which is not so easy
with PL259 as I'm not aware of any cal kits!
It looks to me like you have the open, short and load from an Agilent
85033E 3.5 mm cal kit in the picture, with BNC adapters on them. But
if they are present when the calibration of the VNA is performed, the
error correction will not be correct, as the offset delays of all the
standards will be increased dramatically.
From memory the offset delays of the opens and short in that kit are
around the 30 to 32 ps, but your adapters will probably add double
that, so all the error correction wil be wrong.
2) Assuming you got a valid calibration, again there is no mention of
the effect of the BNC to SMA adapters. But if the calibration is not
valid, it changes things a lot.
Dave
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