Re: signal leads that pick up less ambient noise?

"Christopher Howard" <christopher@librehacker.com> wrote in message news:871pvlsz2s.fsf@librehacker.com...

Bill Sloman <bill.sloman@ieee.org> writes:
>

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

Google for coaxial feed through capacitors.

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.

>
So, when you use a coaxial feed through capacitors on your faraday cage,
do you add a resistor right after the capacitor, to reduce/eliminate
ringing? Or are you just trying that all your inputs on the board have
resistors before whatever op amps or other components that they feed
into?

Start with only feedthrough capacitors which have a capacitance to ground which it not going to have any detrimental effect on your
circuit.
Don't worry about ringing at this stage.
If you still have issues with unwanted signals being conducted in or out of the cage then additional filtering such as a series
resistor or a more sophisticated filter may be needed.
But in your case I would not worry about that until after I had determined whether or not a problem still exists with only
feedthrough capacitors in place.

>
--
Christopher Howard