Nate Bargmann wrote:
On Sun, 07 Jan 2007 21:47:05 -0800, Richard Clark wrote:
I don't follow the logic of this at all. Are you expecting the trap
to cut off all frequencies above 27.5 MHz?

This is what W8JI's site hints at. Is he wrong, or am I misunderstanding
him?

Unlike low pass filters, traps do not have a low impedance
at lower frequencies and a higher impedance at high frequencies.
The impedance plot Vs frequency is akin to a bell shaped
curve with the maximum impedance at resonance.
--
73, Cecil http://www.w5dxp.com

On Tue, 09 Jan 2007 03:10:28 +0000, Cecil Moore wrote:

Nate Bargmann wrote:
On Sun, 07 Jan 2007 21:47:05 -0800, Richard Clark wrote:
I don't follow the logic of this at all. Are you expecting the trap
to cut off all frequencies above 27.5 MHz?

This is what W8JI's site hints at. Is he wrong, or am I misunderstanding
him?

Unlike low pass filters, traps do not have a low impedance
at lower frequencies and a higher impedance at high frequencies.
The impedance plot Vs frequency is akin to a bell shaped
curve with the maximum impedance at resonance.

Right. That has always been my understanding. I think W8JI was strictly
looking at loss. His page has little commentary as I understand that what
is there were slides at a Dayton forum.

- Nate

--

"The optimist proclaims that we live in the best of all possible worlds,
the pessimist fears this is true."

Nate Bargmann wrote:
I think W8JI was strictly
looking at loss. His page has little commentary as I understand that what
is there were slides at a Dayton forum.

A trap would naturally have higher losses at
its resonant frequency because that's where the
internal circulating currents are the highest.
Detuning the trap would reduce trap losses.
Removing the trap would reduce trap losses. :-)
--
73, Cecil http://www.w5dxp.com