Topband: BOG near noisy powerline on 160

[David Olean]

Are you sure that you are hearing power line noise from the antenna, or 
possibly you are hearing a common mode signal that has bullied its way 
into your antenna system by getting on the outside of your feedline.  Is 
your feed line decoupled at each end with ferrite coax chokes?  The 
choke must be installed about 20-25 ft from the antenna transformer and 
have its own ground rod. There should be another ground rod and choke 
where the coax enters your building.  You might also have energy getting 
into the BOG system from another feeder or wire antenna that may be 
picking up noise and coupling it into the BOG system.   Why do I say 
this? (Been there, done that!) Most of my power line noise was common 
mode energy picked up from other places.

Dave K1WHS

On 2/8/2019 4:31 PM, N4ZR wrote:
> Recently I put down a 220' BOG, using the KD9SV hardware, including 
> the preamp. Because of my yard's layout, the forward end of the BOG 
> fell within about 20 feet of what the power company has identified 
> (but not fixed yet), a noisy line with a number of broken insulators.
>
> I came in to listen to the antenna, and was surprised to note that my 
> noise (mostly from the powerline, by ear) is worse on the BOG than on 
> my jury-rigged sloper transmit antenna.  It is much (maybe 20 dB) 
> worse in the direction toward the power line than in the opposite.  
> While I take this as encouraging evidence that the BOG has some 
> directivity, I don't think I'm even hearing any atmospheric noise that 
> may be present, because of the power line.
>
> So now I'm wondering, is the BOG in this position worth keeping, even 
> assuming that I can eventually get the power company to fix the line. 
> Or should I look at another type of receiving antenna, such as a K9AY 
> loop or SAL, which can be placed much farther from the power line?
>