IARU Contest Mults

WJ2O at aol.com WJ2O at aol.com
Mon Jul 8 01:34:49 EDT 1996

Hi gang,

Has anybody compiled a list of active IARU HQ stations and their respective
abbreviations?  Sure could use one.

73, Dave, WJ2O (FM/WJ2O this weekend)

>From n0dh at comtch.iea.com (Dave Henderson)  Mon Jul  8 20:18:59 1996
From: n0dh at comtch.iea.com (Dave Henderson) (Dave Henderson)
Date: Mon, 08 Jul 1996 12:18:59 -0700
Subject: 160M antennas and parts
References: <v01540b00ae056a1930fc@[]>
Message-ID: <31E15F23.6312 at comtch.iea.com>

Alfred J. Frugoli, KE6BER/1 wrote:
> I am in the planning process for a 160M contest antenna.  I know that there
> is much to be said for inverted L's and towers as 160 antennas.  I am
> currently looking at putting up either an inverted L or a 50ft top loaded
> vertical.  Here are my questions.

Al I have used Inverted L's for years in the following configuration.
Total length on the "L" (verticaL + horizontal) of about 160' This raises the 
feedpoint impeadance to around 50 ohms. 
> 1) Are there any references out there on specific construction techniques
> for coils and matching networks.  (I need these components to handle
> legal-limit)

In the above configuration I then use a series cap to tune out the inductive 
reactance. The important thing in this configuration is the ability of the 
cap to handle large amounts of current. typically you will be looking at 
something around 300pf. I used to use three of the old 100pf 2.5kv surplus 
transmitting type micas in parallel. I since got a very good deal on a 500pf 
/ 5kv vacummn variable at a hamfest which allows me to do all my "pruning" 
from the ground!

> 2) What are the effects of having the vertical portion of an inverted L
> next to a metal support (i.e. a tower).

 I have never tried this as I always hang my L's form the trees but the 
computer models suggest a reduction of about 1 to 2 db depending on the the 
tower configuration. 
> 3) Is there any antenna modeling software that will help me with figuring
> radiation resistance, capacative loading, matching etc that will run on a
> 386 w/dos, or a Mac?

I personally use NEC WIRES by Brian Beasley. It runs on a 386 ok. But to get 
really good results a model with enough "segementation" could run for 10 
minutes or more on 386/33. This is true of most any of the software packages 
out there most of which are based on NEC or Mini_NEC. A math coprocessor is a 

OH yeah...plan on putting your money in the ground radials. I have two L's in 
phase here. To date I have about fifty 1/4 radials under each one which 
amounts to 13,000 feet of wire and I'm still adding on ! It will work with 
less but if you wanna kick "@$$"..........

dit dit

PS: There is a 160 meter "reflector" at <topband at animas.frontier.net>. To 
subscribe send "Subscribe" to <topband-request at frontier.net>

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