Topband
[Top] [All Lists]

Re: Topband: Low band antenna project questions

To: topband@contesting.com
Subject: Re: Topband: Low band antenna project questions
From: Jim Brown <jim@audiosystemsgroup.com>
Reply-to: jim@audiosystemsgroup.com
Date: Mon, 7 Mar 2016 15:11:58 -0800
List-post: <topband@contesting.com">mailto:topband@contesting.com>
On Mon,3/7/2016 2:37 PM, Bill N6MW wrote:
The V7 version with 2 drooping T wires and 2 elevated radials for each band was just okay on 160 but good on 80,

Drooping Tee wires will reduce the effective height of the antenna by a significant fraction of their droop.

probably limited by trees proximity and restricted geometry, although some might claim enhanced by being on a beach with adjacent ocean.

Verticals near the beach need an effective radial/counterpoise. Only if the feed is directly over water and the coax return makes very good contact with it will sea water serve as a counterpoise. The vertical pattern of any antenna is produced by the reinforcement of the direct wave by the first reflection from the earth. That reflection is MUCH stronger, and is strong at a lower angle, if the "earth" at the point of reflection is sea water. Sea water will NOT improve signal strength in directions where the first reflection is over land.

73, Jim K9YC
_________________
Topband Reflector Archives - http://www.contesting.com/_topband

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