Re: Insertion delay needed for BNC-BNC couplers UG491A/U (M-M) and UG914/U (F-F)

Kurt Poulsen

Hi John

The drop end of sweep is a free bonus. The cause has been mentioned to Tom but he has no clue. Only seen for such extreme fin resolution as 0.1ps/div.
You have still not understood my point about frequency dependency for the female short if it is what you try to demonstrate with the plot attached.
Please load the BNC female kit and ensure it is in arbitrary mode. The open a custom trace and enter in the expression field s_short. This custom trace is not the s parameter for the female short, but as you cannot use extension port delay on anything else than the S11/S22/S21/S12 traces you need to copy the custom trace to S11. But before that set the frequency span to 0.03 to 600MHz or 1.3GHz and after the copy of custom trace to S11 then extension port delay show you the frequency dependency. I prefer linear and not log for this presentation. I know you love log which is super to hide the detail in the high end

Kind regards



-----Oprindelig meddelelse-----
Fra: <> På vegne af John KN5L
Sendt: 23. maj 2020 19:12
Emne: Re: [VNWA] Insertion delay needed for BNC-BNC couplers UG491A/U (M-M) and UG914/U (F-F)


Attached is Female Open measurement with port delay set to calDelay/2


100 point trace. What I've noticed is last point, 100MHz, always goes into the weeds. Others noticed this? Blip near 45MHz is sound card frequency.


On 5/23/20 11:59 AM, John Oppenheimer wrote:

> Hi Kurt,


> On 5/23/20 10:54 AM, Kurt Poulsen wrote:

>> The internal structure of the female female adaptor is also not ideal

>> as there sare sections not filled with PTFE


> Yes, had noticed that yesterday. Female Open Delay without inside PTFE

> is -177.82 where as using an open with internal PTFE (031-320-RFX no

> pin) is -187.6





Best 73 de Kurt de OZ7OU

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