On Tue, 11 Jul 2006 13:02:48 +0100, "John Hague"
wrote:

On Tue, 11 Jul 2006 08:29:05 +0100, Roy Lewallen wrote:

Ben Jackson wrote:
. . .
Anyone have any tips for securing fine-wire toroids in
Ugly/Manhattan construction?

A dab of hot melt glue or RTV. Or a Nylon screw through the middle. Or a
couple of holes in the board and a cable tie. The only thing to avoid
is laying it down flat on a solid copper plane.

Roy Lewallen, W7EL

Roy

Excuse my ignorance, but what is the problem with laying a toroid down on
a solid copper plane? I thought the magnetic field was contained within
the toroid and thus minimised external effects. I have completed a couple
of projects recently with some of the inductors like that and didn't
notice any real problem. Mind you, I guess they might have performed
better if not mounted that way )

Twofold. One is added capacitance across the windings and secondary
is the proximitry of a conductor to the small field around the wire(s)
that are not in direct contact with the toroid.

Allison



Best 73

John, G4GOY