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Old January 29th 04, 04:15 PM
Richard Harrison
 
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Cecil, W5DXP wrote:
"The requirement is that the coil be self-resonant at the operating
frequency."

That`s what I remembered. It`s as if a parallel resonant LC circuit is
substituted for a quarter-wave short-circuited stub inverting the phase.

My problem is finding the page in Kraus` 3rd edition. Anyone have the
number?

Best regards, Richard Harrison, KB5WZI

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Old January 29th 04, 06:05 PM
Cecil Moore
 
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Richard Harrison wrote:
My problem is finding the page in Kraus` 3rd edition. Anyone have the
number?


Page 824
--
73, Cecil, W5DXP

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Old January 30th 04, 06:34 AM
Richard Harrison
 
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Cecil, W5DXP wrote:
"Page 824"

Yes. Thank you very much. I had lost track and seemed not to be able to
find the item again.

The illustration is Figure 23-21 (b). Four in-phase 1/2-wave elements
with phase-reversing coils. Kraus says:
"Here the elements present a high impedance to the coil which may be
resonated without an external capacitance due to its distributed
capacitance. A phase reversal is about 180-degrees.

Best regards, Richard Harrison, KB5WZI

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Old January 30th 04, 02:15 PM
Cecil Moore
 
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Richard Harrison wrote:
Cecil, W5DXP wrote:
"Page 824"

Yes. Thank you very much. I had lost track and seemed not to be able to
find the item again.


Those little sticky tabs solve the problem.

The illustration is Figure 23-21 (b). Four in-phase 1/2-wave elements
with phase-reversing coils. Kraus says:
"Here the elements present a high impedance to the coil which may be
resonated without an external capacitance due to its distributed
capacitance. A phase reversal is about 180-degrees.


Thanks Richard, there are apparently still old wives
who believe that a coil cannot reverse the phase of the current
even though a shorted stub can. I'm going to post the current
magnitudes and phases for a number of 3/2WL configurations along
with the gains.
--
73, Cecil http://www.qsl.net/w5dxp



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Old January 30th 04, 02:24 PM
Cecil Moore
 
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Mike Coslo wrote:
Well Richard, have you not heard of the famous aperture mask?
Reduces the aperture of the telescope, and there are people that swear
by them!

And, they don't work either.


Mine works well to reduce the light from the moon to a comfortable
viewing level for my 18" diameter reflecting mirror.
--
73, Cecil http://www.qsl.net/w5dxp



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Old January 30th 04, 09:13 PM
Richard Clark
 
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On Fri, 30 Jan 2004 08:24:34 -0600, Cecil Moore
wrote:

Mike Coslo wrote:
Well Richard, have you not heard of the famous aperture mask?
Reduces the aperture of the telescope, and there are people that swear
by them!

And, they don't work either.


Mine works well to reduce the light from the moon to a comfortable
viewing level for my 18" diameter reflecting mirror.


So do moonglasses.
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Old January 30th 04, 09:19 PM
Cecil Moore
 
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Richard Clark wrote:

wrote:
Mine works well to reduce the light from the moon to a comfortable
viewing level for my 18" diameter reflecting mirror.


So do moonglasses.


If you don't mind looking like a dorky nerd. :-)
--
73, Cecil http://www.qsl.net/w5dxp



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