[time-nuts] HP 5065A super

[Bob kb8tq]

Hi

> On Feb 23, 2018, at 6:17 PM, jimlux <jimlux at earthlink.net> wrote:
> 
> On 2/23/18 1:33 PM, Bob kb8tq wrote:
>> Hi
>>> On Feb 23, 2018, at 4:23 PM, Attila Kinali <attila at kinali.ch> wrote:
>>> 
>>> Hoi Bob,
>>> 
>>> On Thu, 22 Feb 2018 21:58:09 -0500
>>> Bob kb8tq <kb8tq at n1k.org> wrote:
>>> 
>>>> The same nickel plating effect gets into a lot of things. If you are shopping for very
>>>> low IMD connectors, nickel plating is out. Things get non-linear (to a very slight
>>>> degree) when it is present. If -180 db is the goal for those spurs, you might only
>>>> hit -120 db with the nickel connectors …..
>>> 
>>> Interesting. About what frequency range are you talking?
>> UHF up into microwaves. It was part of a lecture back when I was in school … I
>> assume the basic physics hasn’t changed since then :)
> 
> 
> Passive intermodulation distortion? What is the physics... hysteresis curves in the magnetization of the nickel is what I would suspect.
> 

It turns out that the nickel’s really awful magnetic properties at RF get it into all sorts
of problems. More or less, the issue is the non-linear field response in the vicinity
of the nickel. You go from “reasonable skin depth” to “don’t go there” in zero distance
when you hit the nickel plating. Past that it gets a bit complicated and it was a very long
time ago ….

Bob



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