Re: signal leads that pick up less ambient noise?

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 40kHz periodicity suggests that old cheap switching power supplies are the source of the noise.
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Bill Sloman, Sydney