Re: RF Metrology

On Sun, 29 Sep 2024 22:08:25 +0200, Jeroen Belleman
<jeroen@nospam.please> wrote:

On 9/29/24 20:57, John R Walliker wrote:

On 29/09/2024 19:02, Jeroen Belleman wrote:

On 9/29/24 19:14, Cursitor Doom wrote:

Greetings, gentlemen,
>
[...] Chinese N-type to
SMA adaptor at the signal generator output. Would I be right to
suspect some imperfection in the manufacturing of the adaptor could
cause such an effect? I do have a VNA I could characterize the adaptor
with but it's a bit of an effort to do. It would seem like the SA is
showing the adaptor's shortcomings in the frequency domain. But is
that a feasible hypothesis?
>
Your pal,
>
CD.

>
Aren't we getting a teensy bit lazy?
>
Jeroen Belleman

 
I have seen transmission (S21) losses of around 1dB at about 1.2GHz
just from failing to tighten an N connector sufficiently.
We do need to know the magnitude and frequency of the problem in
order to give helpful comments!
John
 

>
I collected some TDR traces of various connectors, adapters and
terminators a few years ago: <https://cern.ch/jeroen/connectorTDR>.
>
There were a few surprises. I was taken aback by the poor results
for H+S BNC and LEMO-00. For BNCs, Radiall is better than H+S, but
for N-connectors, it's the reverse.
>
After having seen what LEMO-00 hardware did to my signals, I was
pleasantly surprised by the performance of SMC.
>
SMA was the best I had around, hands down, no surprises there.
>
Jeroen Belleman

SMBs are surprisingly good, and easier to use.

Shining Star makes nice, crazy cheap, edge-launch SMAs and SMBs.

https://www.dropbox.com/scl/fi/x8w5izvfvg87bit10vty4/SS_SMB_Edge.JPG?rlkey=8xsf1wlw73wopi9vlf0slh52g&raw=1