Topband: BOG height

Sat Aug 3 18:47:18 EDT 2019

Guy,

Thanks and two initial questions:

1) what are the consequences good or bad if the wire is 2 inches above the
ground?

2) any recommendations on a BOG amplifier?

Thanks

Paul

On Sat, 3 Aug 2019 at 23:29, Cecil <chacuff at cableone.net> wrote:

> Guy...a great post!
>
> Great information for those of us who are looking for RX antenna options
> but don’t have the room for the normal RX antennas...
>
> And also a real breath of fresh air in light of our recent discussions..
>
> Thank You!
>
> Cecil
> K5DL
>
> Sent from my iPad
>
> > On Aug 3, 2019, at 5:17 PM, Guy Olinger K2AV <k2av.guy at gmail.com> wrote:
> >
> > Hi, Ed,
> >
> > You're on the right track.
> >
> > A "beverage" ON the ground really is NOT a beverage.  For two things to
> be
> > called the same genus, they need to have most everything in common. This
> is
> > true of big yagis, little yagis, short yagis, long yagis, trapped yagis,
> > linear loaded yagis, end loaded yagis, moxons, yagis at 30 feet and yagis
> > at 200 feet, etc. One program optimizes them all. A yagi is a yagi, is a
> > yagi, is a yagi, and all of them have a ton of yagi-ness held in common.
> > Simply not so BOG vs. beverage.
> >
> > Creating beverage advice from one particulars person's wire down close to
> > or on the ground at their particular property, may be simply and totally
> > wrong for someone else. The normal beverage tuning instructions, usually
> OK
> > for wires a foot off the ground and maybe even OK to some degree for four
> > inches, simply do not apply if the wire is actually laying on the ground.
> >
> > A regular beverage has a decent RX signal strength. To be truthful, a
> > **real** BOG needs a remote amplifier, because its output is way down
> from
> > a real beverage. Get this much straight: an actual BOG is a LOW output
> > antenna, period. The way to improve a BOG's signal output is add an amp
> > (best remote), or escape BOG-iness and lift it off the ground.
> >
> > If you model a real BOG, you find that beyond an ELECTRICAL half wave ON
> > THE WIRE, or two hundred something feet on 160, extending the BOG wire
> will
> > start to REVERSE the pattern. No real beverage ever does that. Just some
> > beverage lengths are bit better than others FOR REAL BEVERAGES. A BOG is
> a
> > single band antenna for optimums. It will hear stuff on other bands, but
> > forget a designed pattern like you have on a beverage for several bands,
> > that work WELL on several bands.
> >
> > If you are even two inches above actual ground, laying on top of grass,
> you
> > are blending the very different worlds of pure BOG and pure beverage. If
> > you are at two inches, you are at a poor place to advise either owners of
> > pure BOG's or pure beverages. The great problem is that exactly which
> type
> > you are closer to depends on the vagaries of the location-specific ground
> > underneath.
> >
> > These vagaries wander HUGELY ( I'm talking about an actually carefully
> > ****measured****  wandering HUGELY) depending on individual properties.
> > Based on those **measurements** it is a normal outcome that one end of
> the
> > wire could be more BOG and the other end of the same wire could be more
> > beverage, and even vary more depending on whether it rained in the last
> few
> > days (or weeks depending on the local and natural drainage of the soil).
> >
> > It is clear reading a lot of the posts on BOG's from the last week or
> two,
> > that a lot of users were expecting greater signal output. Don't. A REAL
> > *BOG* that was laid down, notched in the grass down to the actual ground
> > surface, to get it out of sight and safe from lawn mowers, WILL sound
> MUCH
> > better to the ear if it has an amp. Otherwise, a BOG is a LOW LEVEL RX
> > antenna.
> >
> > IN GENERAL, a real BOG needs an amplifier, will usually wind up somewhere
> > 180 to 230 feet if you want front to back, and it's great advantage is
> that
> > it can't be mowed, snagged by galloping deer, have tree branches knock it
> > down, be seen by unfriendly neighbors and it will do roughly as well as a
> > single direction K9AY, but without the AY's ugly wires above the ground,
> IF
> > it's amplified. If the feed circuitry is done correctly, a BOG will be
> > wonderful at reducing local noise off the sides.
> >
> > You will increase signal level significantly by getting it up an inch or
> > two on top of the grass, but it ain't a pure BOG anymore, the VF is
> > increased significantly, and then it needs more length to be optimum at
> two
> > inches. And you will still not be able to tune it smartly like a beverage
> > using SWR to the terminating resistor.
> >
> > BOGs are a cantankerous RX antenna. You can throw a 250' wire down on top
> > of the lawn and take it up after the contest. In normal (not super quiet)
> > settings it WILL hear a lot of signals better than the inverted L. Just
> > understand that is NOT a design antenna, and was not optimized, did not
> > have the best signal to noise of a designed-for-location BOG antenna, and
> > was not as good as a beverage.
> >
> > We know what the issues are, but new-comers to the BOG idea just don't
> know
> > the vagaries and how to squeeze the best out of on THEIR property.
> >
> > The category is Ground Low Velocity Factor (GLVF) antennas. DOGs, LOGs
> and
> > BOGs. If they're up in the air, even two inches, they're likely NOT GLVF.
> > GLVF are low output RX antennas. If you are looking for high signal
> output
> > from the antenna without an amplifier, just forget GLVF.
> >
> > Been there, done all of that.
> >
> > 73, Guy K2AV
> >
> >
> >> On Thu, Aug 1, 2019 at 2:57 PM Ed Sawyer <sawyered at earthlink.net>
> wrote:
> >>
> >> Isn't  BOG still a beverage just with more ground coupling loss because
> its
> >> literally "on the ground"?  So the typical answer on beverages seems to
> be
> >> that 4 - 10 ft above the ground is low enough to eliminate the undesired
> >> noise but high enough to reduce the losses from being too low to the
> >> ground.
> >> A BOG is a beverage with higher than desired losses.  But if its long
> >> enough, pointed in the right direction, and your ground conductivity is
> >> accommodating, its less of a trade than the reverse of those items.
> >>
> >>
> >>
> >> I have had a few unplanned BOGs that were discovered as "on the ground"
> >> because of some supports falling down.  I could immediately hear the
> >> difference, but they still worked.  Would they be usable if that was my
> >> only
> >> option?  Sure.  Just not as good as the same wire at 6 - 8 ft.
> >>
> >>
> >>
> >> I use 650 - 1000 ft terminated beverages and they are quite amazing.  My
> >> ground condition is lossy and I don't have much local noise to null out.
> >> Its pretty much all atmospheric noise.
> >>
> >>
> >>
> >> Ed  N1UR
> >>
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