[Boatanchors] Speech Amp Again

[J Forster]

You might find some ferrite beads (big ones) help with RFI problems. They
increase the loop impedance at RF, but do not alter differential mode audio
signals.

-John

=================

Mike Andrews W5EGO wrote:

> On Wed, Nov 19, 2008 at 02:53:04PM -0500, Carl wrote:
> > Shielding may create a ground loop problem between units. If hum is a
> > problem try the shielding with grounding at one end at a time and then
> > both. As John said twisting is the most important step, as it cancels
> > common mode problems.
> >
> > Im using twisted # 16 cloth covered wire (just like in the old days) to
> > both of my modulator decks with no hum pickup.
>
> Another dodge I've seen used in cases where fields were strong enough
> to cause RF pickup problems, but where connecting the shield at both
> ends caused ground loop problems, was to use double-shielded cable,
> with the inner shield connected at one end and the outer shield at
> the other.
>
> This probably is overkill for your situation, but has worked as a last-
> ditch remedy in a few places. I expect that twisted pair wiring will
> suffice in 90% or more of the cases.
>
> --
> Mike Andrews, W5EGO
> mikea at mikea.ath.cx
> Tired old sysadmin
> _______________________________________________