Re: signal leads that pick up less ambient noise?

On 22/02/2025 3:17 am, Edward Rawde wrote:

"Bill Sloman" <bill.sloman@ieee.org> wrote in message news:vp95q9$395rh$1@dont-email.me...

On 21/02/2025 4:07 am, Edward Rawde wrote:

"Bill Sloman" <bill.sloman@ieee.org> wrote in message news:vp6drd$2mqf1$1@dont-email.me...

On 20/02/2025 5:35 am, Christopher Howard wrote:

Hi, I have a very noisy workbench (lots of digital computers and
computer monitors nearby) and it seems like I pick up a lot of noise on
the long leads coming out of the signal generator BNC output - around
600 mV p-p. I am wondering if there are any particular leads I could buy
that would somehow pick up less ambient noise.

>
You might think about double shielded coax.The standard woven braid outer offers about 98% shielding and adding a wrap of
aluminised Mylar underneath it get you closer to 100% shielding.
>
As other posts have pointed out, your problem is probably going to be earth loops, and wrapping a short length of the coax
around
a ferrite toroid can help with that. Ralph Morrison wrote the book on the subject back in 1967. I read the first edition back
then, and I've had access to most of the subsequent editions. I've got the fourth edition from 1998 when I finally had to buy my
own copy.
>
https://books.google.com.au/books/about/Grounding_and_Shielding_Techniques_in_In.html?id=IxUjAAAAMAAJ&redir_esc=y\

>
The sixth edition (2016) appears to be called
Grounding and Shielding: Circuits and Interference.
And is not hard to obtain.
But unless you want to wade through a book which touches on the calculus of electromagnetic theory (and it's perfectly fine if
you
do), you're likely better off focussing on the practical side of things.

>
Wrong.

 Of course Bill. It was predictable that you'd reply like the headmaster.

Spending time as a senior engineer supervising more junior engineers does encourage that kind of behavior. The junior engineers who resented having to learn more about what they were doing, and who couldn't see the point, did react predictably.
You are posting here because you haven't been able to find out stuff for yourself. So am I but I seem to have tried harder.

I spent perhaps half an hour looking through the book you mentioned (sixth edition).

I got impressed by the first edition, and ended up buying the fourth edition when I was no longer in a position to get my employers to buy a copy.
Half an hour wouldn't be enough time for me to get through the book (and I do read unusually fast). It seems to have been enough time for you to confirm your prejuduces.

I can't quite put my finger on why, but I noticed that when talking about skin depth (Page 26, 74 and others) the word "Penetration"
is used.

Not unnaturally.

This made me wonder how long it might be before I tell you what you can go do with yourself.

You seem to have been slow to understand what I've been saying about you. Thick-skinned would be one way of saying it.

Ralph Morrison's book is sublimely practical; it includes enough electromagnetic theory to let you understand what is going on.
Cook-book style texts don't, and should be avoided.

<snipped the rest of the stuff you haven't understood>
--
Bill Sloman, Sydney