On Nov 12, 2004, at 7:20 AM, StephenTetorka@cs.com wrote:
Say his single loop is about 2 inches in diameter.
Inductance is around 0.1 microhenries.
At 50 MHz XL is 30 ohms; at 150 MHz its 95 ohms.
Using 0.010 inch diameter wire having a Resistivity of 200, the wire
resistance is 2 ohms per foot.
Say 1 foot was used for his coil.
Q is 15 @ 50 MHz and 48 @ 150 MHz.
Resonance for 50 MHz needs about 95 Pf and about 10 Pf for 150 MHz.
As I understand it, Stephen, the lossy pickup hoop in the 100kW
amplifier was not resonated. My impression was that the hoop was
larger than 2-in diameter. What I would like to find out is: How
does one optimize the placement, diameter and orientation of a lossy
hoop?
Notes:
Wire diameter of 0.010 inches is 30 AWG which is rather small.
Wire Resistivity for 'resistance wire' ranges from 30 to 875
Ohms/Circular-Mil-Foot...Copper is 13.71
"R. Measures" <r@somis.org> wrote:
On Nov 11, 2004, at 1:39 PM, StephenTetorka@cs.com wrote:
Hi all:
Been thinking.
If some of these rigs 'want to' go parasitic, would it be beneficial
to help them via a broadband VHF resonant circuit that is coupled to
the HF RF tank with that VHF LC discharging into a dissipative
side-load?
According to a friend who used to work for an amplifier manufacturer,
their 100kW MF-HF model had a resistance-wire hoop suspended in the
output compartment to dampen the compartment's VHF resonance.
Regards,
Steve
WA2TAK
_ Richard L. Measures, AG6K, 805.386.3734. www.somis.org
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