Topband: BOG height

[Cecil]

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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