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Topband: Inverted L bandwidth

To: "Topband post" <>
Subject: Topband: Inverted L bandwidth
From: "Jon Rudy-MCC Asia Peace Resource" <>
Reply-to: Jon Rudy-MCC Asia Peace Resource <>
Date: Mon, 8 Mar 2004 08:56:46 +0800
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Hi all:

The bamboo tower featured in the ARRL Web extra article posted a 2 years back 
has succumbed to the elements (termites and rot).  I built one myself this time 
and hoisted it up yesterday with the help of 5 or 6 people.  It nearly crushed 
me in the process but made it up. I now have the open end of my Inverted L up 
about 45-50 feet (about 30 feet above my tin roof) which is higher than the old 

I immediately noted that the SWR went flat, as flat as I have ever seen any 
antenna on the Alpha 76. 0 reflected (whereas before I had about 50 w reflected 
with 700 fwd). The bandwidth is now from 1.800 to 1.875 for 2:1 SWR.  I am 
using a Battle Creek Special match box at the base (80/160 Balun switch) and 
feeding the antenna with about 120 feet of RG8X. I have about 8 radials over .1 
wavelength bundled  together going 2 directions and about 30 that are 3-5 feet 

My question is it seems like the bandwidth is too much and the SWR too low.  I 
don't trust it although the amp does not sputter and complain. I managed to 
work OH5VT this am so it must be radiating somewhat. Is that BW normal for that 
kind of matching?

I am on most evenings after SS and every morning at SR but condx have been poor 
and noise high here.


Jon Rudy
Davao City, Mindanao, Philippines
Zone 27, Grid-PJ27, OC-130
EX: 3DA0CA, 4D71/N0NM, 
       4D71NM, A2/ZS5UZ, 
       C91CO, ZS5UZ, WB0UZZ
QSL via W4DR

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