[Lowfer] What kind of antenna ?

[Warren K2ORS]

Excellent video, thanks John!

Warren

On 9/8/2016 5:28 PM, listread at lwca.org wrote:
>>
>> https://www.youtube.com/watch?v=C65u7Pmz7a0
>>
>
> A very good demonstration of feedline induced noise effects and their
> remedy...and also, if you think about it, pretty conclusive proof that
> loops are not "magnetic sensors" except for energy stored within the near
> field of a source (ie, noise), and that whips are not "electric sensors"
> except in the near field.
>
> And for that matter, a whip on a pole with a connection to ground is
> scarcely a probe, "e" or otherwise; it's an earthed off-center-fed dipole
> at best, and if the shield is not isolated from ground at one end or the
> other, then it's also a loop antenna with mutual coupling to one side of
> the whip input.  Not a worthwhile loop, either... one that's too low to
> contribute to signal pickup, but is instead in a fine position to couple
> noise from the end nearest the house into the rest of the antenna.
>
> Breaking up that loop with an isolated power source so that only one end
> is grounded, as Doug did, and/or deploying other isolators inline, are
> recognized solutions for this problem that (I have lately discovered) date
> back to World War I.
>
> John
>

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