Topband: BOG antennas

[Jeff Wilson]

    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


Message: 1
Date: Wed, 1 Apr 2015 18:09:26 +0200
From: Filipe Lopes <ct1ilt at gmail.com>
To: Frank Donovan <donovanf at starpower.net>
Cc: topband <topband at contesting.com>
Subject: Re: Topband: BOG antennas
Message-ID:
    <CAFQcihSaDMx=C90oYysV8=wUyTTgMna=CzzU2PSrxr=mzLrqtQ at mail.gmail.com>
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Thank you Frank. Will have a look at it.

73's Filipe Lopes
CT1ILT - CR6K
F4VPX - TM3M

2015-04-01 16:55 GMT+02:00 <donovanf at starpower.net>:

> Hi Felipe,
>
> Suggest you examine this website:
>
> http://n4dj.com/Beverage.html
>
> 73
> Frank
> W3LPL
>
> ------------------------------
> *From: *"Filipe Lopes" <ct1ilt at gmail.com>
> *To: *"k1fz" <k1fz at myfairpoint.net>
> *Cc: *"topband" <topband at contesting.com>
> *Sent: *Wednesday, April 1, 2015 3:18:01 PM
> *Subject: *Re: Topband: BOG antennas
>
>
> Hello Bruce,
>
> This is a very interesting subject.
>
> I am about to "maybe" test a BOG here at my French QTH and I am wondering
> if there are any tests made with best terminating resistance (235ohm? )
> should I use a 9:1 transformer or 10:1 ?
>
> how does it perform compared to a usuall beverage?
>
> Can I cross 2 BOGs for 2 directions or more? will this affect the antenna
> pattern?
>
> I recently built an W7IUV preamp, will it be OK for the BOG ?
>
> Thanks in advance.
>
>
> 73's Filipe Lopes
> CT1ILT - CR6K
> F4VPX - TM3M
>
> 2015-04-01 16:43 GMT+02:00 k1fz <k1fz at myfairpoint.net>:
>
> > To BOG, or not to BOG, that is the question.
> >
> > Many are aware of the good, and bad points of the antenna.
> >
> > Good:
> > Is out of sight.
> > Requires a small space to function well
> > Typically has less noise than an above ground Beverage
> > As disturbed condx (QRN crashes) begin, it can be the quietest antenna.
> >
> > Bad
> > The Pattern can be poor if its too long.
> > Can be tough on a lawn mower.
> >
> > Note: Above ground Beverage antennas can cross as the low ~470 ohm
> > impedances do not couple well.
> > A typical BOG antenna has an even lower  impedance of ~235 ohms and
> really
> > does not couple well to
> > other antennas, metal objects. ( I still avoid going over the radial
> > field.)
> >
> >
> > 73
> > Bruce-K1FZ
> > For more info, try a BOG antennas search.
> >
> > Not an April 1st joke !
> > _________________
> > Topband Reflector Archives - http://www.contesting.com/_topband
> >
> _________________
> Topband Reflector Archives - http://www.contesting.com/_topband
>
>


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