Bob Miller wrote:
On Sat, 30 Dec 2006 19:03:14 GMT, Carter-k8vt
wrote:

Ron Hardin wrote:

The upscale Lutron dimmers are pretty good (around $30) Diva or better, with
more RFI suppression than usual.
Interesting! Didn't know Lutron had an upscale ($30) version. The Lutron
I am waiting to put in was 15 bucks at Home Depot, about triple the cost
of the cheapies they sell.

Dumb question, do the dimmer contraptions make noise only when a light
is on, being dimmed, or do they also produce noise when the light is
off and/or not being dimmed.

*Generally*, only when the light is being dimmed. The better switches
have a detent for full on and full off, thus bypassing the dimming
circuitry. They typically use a thyristor or SCR for the dimming
function and it works by varying the width (chopping off) part of the
sine wave. As you get away from the pure sine wave (full on/no dimming),
the waveform becomes more and more distorted and causes the interference.

I've got a few old dimmers that came with the house, and this may be
one of my noise sources.

There is a very good chance of that being a true statement. Easy enough
to check by just turning them all the way off and see if the noise goes
away.

Good luck and HNY...
73,
Carter
K8VT