[Amps] UHF connector discussion For Dummies

[Jim W7RY]

>> Summary for people like me.... IT DOESN'T MATTER.
>>
>> 73
>> Charles Harpole k4vud at 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 at onetel.net
>>> CC: amps at contesting.com
>>> Subject: Re: [Amps] All the recent UHF connector discussion
>>>
>>> On 13 November 2013 22:45, Larry Benko <xxw0qe at 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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