Topband: BOG height

[K4SAV]

On 8/1/2019 12:36 PM, Mark K3MSB wrote:
> I’ve used BOGs and RBOGs at 200 feet length laying on the ground.     The
> BOG worked great,  the RBOG worked good, but not as good as the BOG.
I agree with K3MSB's conclusions about BOGs.  I have also done a lot of 
experimenting with reversible BOGs and single direction BOGs. Gain of 
the RBOG will be less than that of the single direction BOG.  Impedance 
of the ground rod translates into loss for the RBOG but it is only part 
of the termination resistance for the single direction BOG. The RBOG 
will also not have the same gain in both directions if you build it like 
most people do.  There is a way to fix this problem and that is to use 2 
reflection transformers and feed it in the in middle.  The whole length 
of the wire will be used in both directions and the gain will be the 
same in both directions.  The worst feature of the RBOG at my house is 
that critters like to chew on the wires.  A single wire is a lot easier 
to repair than RG-6.

A BOG is a good antenna but I'm not sure exactly what its RDF number 
is.  NEC doesn't do well for BOGs.  I can calculate an RDF of over 11 
for a 366 ft BOG using NEC but I'm sure that is NOT correct. When 
comparing it to another receiving antenna that has an RDF of 11.1, I 
estimate the BOG is between 9.5 and 10.

A BOG is a pretty simple antenna but there are ways to screw it up. The 
gain is low so you have to be very careful about suppressing common mode 
currents.  And don't aim it at your house and don't run it close to the 
house.

Jerry, K4SAV