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[AMPS] Feedback path 3-500Z

To: <amps@contesting.com>
Subject: [AMPS] Feedback path 3-500Z
From: 2@vc.net (measures)
Date: Fri, 29 Sep 2000 11:56:36 -0700
>
>> "When an antenna is connected things are theorically more complex 
>> because HF antenna impedance can be transformed to high reactive values if
>> one has long enough lines (in term of WL and fractions like quarter
>> waves). Actually I donít see very raccomandable to use lines whose lenght
>> ranges in the area of 375m (1230 FT), a quarterwave at 200 KHz. Agreed
>> that an HF antenna is not 50 +j0 at VLF, the feed point impedance of an HF
>> antenna at VLF is much less than one ohm and largely -j reactive (i.e an
>> open dipole) or few Ohm and slightly inductive +j  in case of closed
>> loops, antennas with baluns, matching devices like hairpin, etc. etc. As
>> previously explained, unless the used line is quite long and acts like an
>> impedance transformer there is no chance an HF antenna will become so
>> higly reactive (+j) to resonate plate load"
>
>It's a big world out there Mauri, with many kinds of loads having 
>many kinds of characteristics, I never said it was a frequent even in 
>the real world, I just said it could be made to happen and can 
>happen. The wrong impedance can occur in hundreds of ways you 
>haven't expressed.
> 
>> My point stay that real chances to have VLF oscillations because of a grid
>> to ground low Q parallel resonant circuit at 200 KHz (or lower) are really
>> minimal, basically equivalent when grid is directly grounded. Final step
>> is if anyone want's to try to start VLF oscillations with an SB220/TL922

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