"Richard Clark" wrote in message
...
On Mon, 27 Sep 2004 09:36:21 -0500, "John Smith"
wrote:

Is there a way to add toroids to RG58 and measure the resulting
effectiveness? Maybe measure the RF on the shield with an RF Voltmeter?

Hi John,

Apply a steady, known power to a resistor (25 - 75 Ohms) and measure
the voltage (more for sanity's sake). Add one core to the lead (make
leads as short as possible, but long enough to allow ONE core to be
added. Measure the drop across BOTH the resistor AND the core.
Measure the drop across EACH, the resistor and the core. Across the
core means at the wire passing through the center, as if the core were
a leaded component with leads emerging from either side (it will NOT
act like a short! - ain't science wunnerful?). Standard ratiometrics
will reveal the core's Z.

You need only measure one core at a time, the addition of cores is
additive just like series resistors. Unlike chained resistors,
successive passes of the same wire through the core raises the Z by
the square of the turns. A "turn" is defined as each passage of a
conductor through the center (do not confuse with loops which may give
rise to the appearance of a "turn" that in fact does not have a lead
through the center; or that you lose a turn by counting only loops).

73's
Richard Clark, KB7QHC

Thanks, Richard. I'll give this a shot. Might not get to it until the
weekend, though.

73,
John