Topband
[Top] [All Lists]

Re: Topband: wideband inv-L

To: "Guy Olinger, K2AV" <olinger@bellsouth.net>,"DAVID CUTHBERT" <DAVIDNNAN@MSN.COM>, <topband@contesting.com>
Subject: Re: Topband: wideband inv-L
From: "Tom Rauch" <w8ji@contesting.com>
Reply-to: Tom Rauch <w8ji@contesting.com>
Date: Wed, 5 Jan 2005 20:24:25 -0500
List-post: <mailto:topband@contesting.com>
> >... However, the slightest loss really extends the
bandwidth and I
> >suspect this is > what many find....

A 1/4 wl vertical from 18" face tower will cover the entire
160 meter band with under 2:1 SWR when over a perfect ground
system.

Decreasing efficiency by exactly half from nearly 100% to
just under 50% just slightly less than doubles bandwidth.

> Yep, the universal bugger on 160. So much so that any sign
of new
> "bandwidth" generates a paranoid scurrying about to
discover what's
> gone wrong.
>
> Stated another way, particularly for 160, bandwidth
implies loss until
> loss has been carefully ruled out.

My highest efficiency mobile antennas have the widest
bandwidth by a significant margin.

A 1/4 wl tower with perfect ground has full band or nearly
full band coverage even with 100% efficiency.

Now if you see a half-wave wire dipole cover 200 kHz, you
need to be worried.

73 Tom

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

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