Re: Lost steps

--- In CAD_CAM_EDM_DRO@egroups.com, wanliker@a... wrote:

> In a message dated 8/22/00 6:18:40 PM Mountain Daylight Time,
> This was also required in Hi Fi Music systems to avoid hum.
>
> Another thing to do is always twist the wire pairs going to motor

etc. This

> helps to retain the EMF fields.
> Sometimes it is also helpful to use a wire braid for the grounds,

this lowers

> the impedance (resistance) of the ground.
> bill

I remember well. Vacuum tube amplifiers using push-pull 6L6s for the
output stage, 5Y3 dual power diodes, but that dates me. I used to
build them as well as superhetrodyne recievers when I was 13 or 14;
pentagrid converters using 1R5s comes to mind.

I guess the point is with linear audio design you could always tell
how effective (or not) your grounding scheme was. Any common-mode
noise made its presence known thru the speaker. If you did well, no
noise; if not, hummm or worse.

Digital circuitry is just as sensitive, only more devious. At the
rails ("1s" and "0s") it has low gain and few problems, but it always
has to pass thru the high gain linear region around the logic
threshold. That is where all the fun happens if the "Is" are not
dotted and the "Ts" are left uncrossed.

Mariss