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Re: [TowerTalk] Q factor question...

To: ve2ryy@globetrotter.net, towertalk@contesting.com
Subject: Re: [TowerTalk] Q factor question...
From: TexasRF@aol.com
Date: Sun, 4 Mar 2007 14:31:09 EST
List-post: <mailto:towertalk@contesting.com>
 
Noel, 3.6 uH has a series reactance of about 40 ohms; a Q of 289 equates to  
a series loss resistance of about 40/289 or about .14 ohms. At 1500w there 
could  be about 6.5 amps of current flowing through the inductor. Loss power 
then 
would  be about 6.5 squared times .14 or about 6 watts. 
 
6 watts lost will make no discernable signal strength difference so the  only 
consideration is if the inductor can safely dissipate the power  without self 
destructing. If located inside a small air tight enclosure, this  might be a 
problem; mounted in the open or larger enclosure, not a  problem.
 
73,
Gerald K5GW
 
In a message dated 3/4/2007 12:19:28 P.M. Central Standard Time,  
ve2ryy@globetrotter.net writes:

I  am  on the way of building the three element parasitic array on 160 meter  
according to ON4UN LowBandDxing book.
In the array, there is a parasitic  element which is a Director...(1.935Mhz)
This same element is used for  Reflector by installing  an inductance of 
3.6UH between the bottom end of  the parasitic and the ground...
Now here is the question.
When making  this inductance, do I have to take account of the Q factor .
I have made  one just for fun, with nr 14AWG wire ...etc....
I get the right inductance  needed, but I find that the Q factor is not very 
high, say about 289  plus  or minus....
Again this inductance is not going to be in the  driven element, it is going 
to be in the parasitic, located about 66 feet away  from the driven element..
I would appreciate  any comments about the Q  Factor in a parasitic 
element....
Thanks
NOEL  
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