Re: signal leads that pick up less ambient noise?

"Christopher Howard" <christopher@librehacker.com> wrote in message news:87a5afnsh1.fsf@librehacker.com...

>
Those boards don't look at all sophisticated. When you say building it
on breadboards do you mean Vero board or some other soldered
prototyping medium or do you mean literally on a plug in patchboard?
>

>
I'm use the common white breadboards where you push the leads and
components in. I'm not sure what the technical term is for those.

I also used those as a teen for very simple things including a cat flap alarm which frightened the neighbours' cats away.
For the circuits you're making I'd use veroboard. Sometimes called stripboard.
https://electronicsclub.info/stripboard.htm
Speedwire is even better but may not be available any more and needs a surgeon's touch.
https://en.wikipedia.org/wiki/Speedwire

Try a simulated ground plane or simulated enclosure made from a sheet of metal foil, a sheet of paper or thin card and the kind of
glue which does not set hard.
Use a paper clip to connect to the foil.

>

Have you checked that your bipolar 15v supply isn't the noise source?
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The noise you are describing at around 40kHz looks awfully like an old
school switched mode PSU sort of frequency.

>
I checked just now, but the noise is not affected at all by turn on or
off the bipolar 15 volt supply. As mentioned earlier, turning off
computers at the desk, especially one older computer, eliminates most of
the noise.
>
--
Christopher Howard