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[Towertalk] 160m Inverted L

To: <>
Subject: [Towertalk] 160m Inverted L
From: (
Date: Sun, 11 Aug 2002 04:58:54 -0600
There are an infinite number of solutions.

The most popular are to tune the length for resonance
where the is ZERO reactance and then match the
(low) real impedance to 50 ohms, OR, to adjust the
length to provide 50 Ohms plus some inductance and
use a single capacitor to cancel out the inductive reactance.

Tom  N4KG

On Sat, 10 Aug 2002 20:17:23 -0000 "Kevan Nason" <>
> After a couple years of 'listening' I've finally joined.
> Thank you all for your help -- even if you didn't know you
> were giving it.  I'm still learning some of the basics
> and thought y'all might help out again.  I'm new to using
> an antenna analyzer.  Used to simply use the SWR bridge.
> I'm constructing an inverted L for 160m and am unsure of how
> to proceed.  My MFJ269 tells me the following:
> Freq    Rad. Resis     XL     SWR
> 1.9         45         155    13.5
> 1.7         32         28     2.3
> I haven't measured my ground characteristics, but judging by
> the general documentation available for this area and the 
> large amount of clay around I figure its poor.
> My question is this.  If antenna efficiency is:
>         eff = Rrad/(Rrad+Rloss)
> and I don't change Rloss by running more radials or some 
> such (I ran out of wire and want to play in the NAQP next 
> weekend); would I be better off leaving the length as is and 
> cancel the inductive reactance with a capacitor, or should I
> keep on trimming the antenna.  If keep trimming, how far?
> Until Xl is zero and then match the antenna using
> a transformer or antenna tuner?
> Kevan
> NS4T
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