[TowerTalk] 160M inverted L question

Earl Morse n8ss2014 at gmail.com
Wed Jan 16 13:00:59 EST 2019


Took a stab at this while I ate lunch today.

> Assuming a 4 foot separation between tower and a 60 ft long 12 ga wire.  I
> get about 140-150 pF of capacitance between the two.  I assumed the tower
> to be an infinite plane to make it easier so actual capacitance between the
> antenna and tower   should be less.  At 1.8M that's about 500-600 ohms of
> capacitive coupling and real capacitance between tower and antenna would be
> even less because of my assumptions.
>

What does the model say?

>
Earl
N8SS

>
>
> ----------------------------------------------------------------------
>
> Message: 1
> Date: Tue, 15 Jan 2019 04:38:03 +0000 (UTC)
> From: RVZ <rlvz at aol.com>
> To: towertalk at contesting.com
> Subject: [TowerTalk] 160m. Inverted L question
> Message-ID: <369232969.276333.1547527083313 at mail.yahoo.com>
> Content-Type: text/plain; charset=UTF-8
>
> Guys,
>
> I've got a 160m. Inverted L with the vertical wire spaced 4' from a
> grounded steel tower at the base and 6' at the top.? The radial system
> isn't perfect but it's decent.??Based upon the Inv. L's poor performance, I
> believe I may have a lot of power being coupled to the tower and shorted to
> ground.? A?couple questions:
> 1) I'd appreciate some guestimates on what percentage of input power may
> be getting shorted to ground?
> 2) Any guestimate on what percentage of power may be saved if the Vertical
> wire spacing is increased from 4' to 12" from the tower??
>
> Thanks & 73,
> Dick- K9om
>


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