Subj : Re: Homebrew antenna questions
To   : alt.ham-radio.vhf-uhf
From : Bob Bob
Date : Thu Sep 29 2005 07:57:28

From Newsgroup: alt.ham-radio.vhf-uhf

Hi Carl

Keeping in mind that I am no expert myself..!

In my view "must ground" is more for lighting protection of equipment. 
Mind you it will only reduce the effect not remove it. The immediate 
problem you then have is that the "ground" at the base of the jpole now 
fights in a way with the ground provided by the coax connection at the 
antenna itself. (And at the rig end where that is grounded) Using a 
balun where some "ground" isolation is created will resolve this issue. 
My view (as previously stated) is that not resolving this problem 
results in feedline and/or mast radiation, both of which would likely 
skew the radiation pattern in undesirable directions. (eg upwards)

I would suspect that using a 4:1 balun would yield a wider VSWR bandwidth.

Grounding the antenna may also mean less noise is induced into it. I 
dont know how true or false that is. It just seems likely in my mind.

I will let others answer your balun question. That topic gets all fired 
up periodically on this NG! When I build my 1/2 wave over 1/2 wave jpole 
for 2m I will be using a 4:1 coaxial balun...

Cheers Bob VK2YQA

Carl / W6VDC wrote:
  > I assume from the reading I have done, that if you ground the antenna
> you should use a balun.  If you do not ground the antenna you don't need 
> a balun?  Is it a good idea to use a balun any way?

.