Topband
[Top] [All Lists]

Topband: trap inv-l

To: "Topband" <Topband@contesting.com>
Subject: Topband: trap inv-l
From: "DAVID CUTHBERT" <DAVIDNNAN@MSN.COM>
Date: Sat, 9 Apr 2005 09:59:56 -0600
List-post: <mailto:topband@contesting.com>
This is in regard to the coaxial trap inverted-L. Tom's article shows us that 
traps aren't bad things to be avoided. But for those who still oppose traps, 80 
meters can be added to a 160 meter inverted-L by placing a 1/4-wavelength (80 
meters) grounded wire 15 cm from the inverted-L. Is anyone here using such an 
antenna? This is based on a NEC simulation and on Monday I can put a 1/50 scale 
model together and see if it really works as simulated. 

However, the 160 meter quarter wavelength inverted-L should make a fine half 
wavelength antenna on 80 meters. For installations that have effective ground 
resistance above 15 ohms this will beat the 80 meter vertical. This is based on 
a 50-50 inverted-L. That is, an inverted-L that runs vertically for 
1/8-wavelength and then horizontal for 1/8-wavelength. It just takes switching 
at the base to change bands. 

    Dave WX7G
_______________________________________________
Topband mailing list
Topband@contesting.com
http://lists.contesting.com/mailman/listinfo/topband

<Prev in Thread] Current Thread [Next in Thread>