Re: [IRCA] Computer Model of Bog

["Neil Kazaross" <neilkaz@xxxxxxxxxxxxx>]

Hi, Gil..my appologies for not getting back to you sooner about my 
experiences with BOG's.

I don't find it possible to accurately model a BOG with EZNEC since I don't 
think it properly takes into account the slowing of the velocity of 
propagation when the wire is on the ground. Additionally, I feel that EZNEC 
can be a bit squirrelly with wires directly on the ground.

However, my experience coincides with the theory and tables I've seen and 
that is that a BOG has a pattern like a typical Beverage of constant height 
that is 2.5 times longer. Also since classic Bevs need to slope to ground at 
both ends I feel that there are a bit less extranious side lobes with BOGs. 
An unterminated BOG has a considerably better F/B than does an unterminated 
Bev. I'd expect the back lobe to be down about 5 or 6 dB midband for a 500 
ft BOG.  You may find my detailed test results posted here to be 
interesting.
http://www.dxing.info/community/viewtopic.php?t=371

Soon after I used my first BOG here, I took down all elevated mini-Bevs and 
for the most part stopped using KAZ antennas (or anything else with a wide 
cardiod pattern) because I have much less signal from the sides off BOGs and 
can phase 2 of them to get great F/B.

A few winters ago, before my property here was torn to shreads in the middle 
due to building our new home, I ran a 317 ft W BOG and a 343 ft WSW BOG out 
my shack's windows. On the regionals and GY's in the upper 3rd of the band, 
I'd often have totally different stations dominating on the respective wires 
and always from near their intended directions. An example was Amarillo on 
1310 with 88 watts being DXable on the WSW and never had on any other 
antenna.

I can play around with longer BOGs up north at my place in WI.  893 feet 
clearly beats 475 feet on the low end as it is more directive. It also has a 
better F/B and thinks like CFRB 1010 come in much better in the day on the 
longer BOG due to better directivity and also better F/B (less WSPT). For 
the top end of the band, anything much above 900 ft is too long if the wire 
is right on the ground since I find that it is too lossy and the pattern 
starts to deteriorate. Even with several hundred feet you'll note lower 
signal levels on stuff up near X-band than with shorter wires, but this is 
OK since directivity is very good.

73 KAZ

----- Original Message ----- 
From: "Gil Stacy" <gilstacy@xxxxxxxxx>
To: "Mailing list for the International Radio Club of America" 
<irca@xxxxxxxxxxxxxxxx>
Sent: Thursday, December 21, 2006 4:54 PM
Subject: [IRCA] Computer Model of Bog


>I would grateful if someone could either provide me by email or direct me 
>to
> a site that has an Enzec or other computer  simulation of a 500' bog,
> unterminated,  and over average ground.  Frequency would be anywhere in 
> the
> MW band.  Thanks.
>
> 73, Gil NN4CW

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