Re: signal leads that pick up less ambient noise?

On 25/02/2025 4:46 am, Christopher Howard wrote:

Joe Gwinn <joegwinn@comcast.net> writes:
 

Google for coaxial feed through capacitors.
>
.<https://www.engineering.com/the-engineers-guide-to-feedthrough-capacitors/>
>
.<https://www.ketemicro.com/tec_info28.html>
>

 Thank you, I've stored these links and started looking through them.
 Question: With a simple C feed through capacitor, with no resistive
element, do you have trouble with ringing? I had thought this was a
reason to use RC filters rather than just C bypass filter, to
reduce/eliminate ringing.

Capacitors and resistors don't ring. Adding inductance can introduce ringing. but enough resistance can make the resonant circuit critically damped and the voltages and current will decay monotonically.
Inductor are added to give you more attentuation but they can ring if the tank circuit created isn't adequately damped by enough resistance around the tank circuit.
One cm of straight wire has an inductance of about 10nH, so bad layout can introduce unintended inductance
--
Bill Sloman, Sydney