BOG antenna notes may be of some help:
www.qsl.net/k1fz/bogantennanotes/index.html
73
Bruce-k1fz
----- Original Message -----
From: "Jeff Wilson" <jjw5257@yahoo.ca>
To: <topband@contesting.com>
Sent: Wednesday, April 01, 2015 8:19 PM
Subject: Re: Topband: BOG antennas
I put a BOG "down" for this winters DX season on 160m and was very
impressed with it, compared to my three 550ft Beverages (NW, NE, S). I did
not have the SW direction covered, so I put up this BOG just after the ARRL
160m contest as it's need was evident following the difficulty hearing on my
TX antenna. So I collected what I had on hand and got to work just before a
big snow storm. No more 8ft rebar for Beverage supports, so I went with a
BOG for the first time.
VE3CV's BOG:
I used 200 feet of #12 gauge stranded insulated electrial wire strung tight
between two 4ft groundrods (3/4 galvanized conduit for one and 3/4 copper
pipe for the other) across a plowed field, so that much of the antenna was
in the air with furrows beneath it. The far end had 3 - 50ft galvanized
fence wire radials added - one in line with the BOG and the other two 90 deg
to either side. The BOG was attached to each ground rod via strain egg
insulators and 3/16" dacron line to tighten it and provide slack to the ends
that were then electrically connected at the acorn connector on the ground
rod (about 6 inches above ground).
The BOG was covered with 2 feet of snow all winter which did not reduce
effectiveness. The termination resistor was 220 ohm (1 watt) - will try
higher value 270 ohm) next year. The matching transformer was 2.78:1 or 3
turns primary and 5 turns secondary using #26 magnet wire and a binocular
core. (as per chart available on W0BTU's great web page). I used about 130
feet of RG-6 and F connectors to feed to the shack. I have a DXE preamp, but
rarely used it and elected to turn the volume to 3/4 maximum with my hand on
the RF gain control of my FT-1000MP to save my ears from the tuner uppers!
This was pointed to Southern California from my Southern Ontario location
(265 deg) and worked amazingly well to pullout the US west coast, VK, ZL,
XE, KH6, etc. This BOG really saved my ears and helped put lots of station
in the log that I would have missed.
It worked on all bands and was probably best on 80m, based on stability of
the SWR:MHz - SWR
1.8 - 4.71.85 - 4.41.9 - 4.22.0 - 3.6
3.5 - 3.23.6 - 3.33.7 - 3.33.8 - 3.33.9 - 3.34.0 - 3.2
7.0 - 2.57.1 - 2.47.2 - 2.37.3 - 2.27.4 - 2.0
10.1 - 2.510.15 - 2.4
Hope this helps Filipe
73Jeff VE3CV
_________________
Topband Reflector Archives - http://www.contesting.com/_topband
|