[Waverley ARS] Amateur radio antenna close to TV antenna

[Mathias Burbach]

Hello Folks,

After having had much success with my balcony antenna on my neighbour's 
balcony on the second floor I am keen to find out what difference it 
would make to place an antenna in the attic or on top of the roof. 
Yesterday I tried my antenna in the attic with poor results. Repeater 
signals were weaker than on my balcony, which I attribute towards 
missing ground on my mobile antenna when it was up in the attic. I will 
give it another go with some wire leading towards the water pipeline of 
my neighbour in the second floor.

I also had an antenna technician coming over yesterday. He inspected the 
attic, checked out the cavity and had a look at the current TV antenna 
mast. It seems the guywires & turnbuckles of the existing TV antenna 
mast are in bad shape and he doesn't recommend to put another antenna on 
top of the existing mast. Instead he suggested to erect a second mast 
for the amateur radio antenna. Whilst I understand his concern I am 
afraid that a base 2m/70cm antenna in proximity of the TV antenna at the 
same height is more likely to cause TVI than an amateur radio antenna on 
top of a TV antenna. If I am not mistaken the radiation characteristics 
of a vertical dipole are that directly above and below the antenna there 
is nearly no wave propagation. Can anyone confirm my theory and would 
also recommend to better place and base antenna on top of the current TV 
antenna? If not why would you say that a second mast/antenna shouldn't 
cause too much trouble?

When the technician had a look at the current TV antenna setup he 
realised that the current antenna/mast is not earthed. I'd say that is a 
risky thing to do and I would certainly not want my antenna on top of 
the roof without earthing. Any comments on missing earthing from your 
side, folks?

Thanks for your comments in advance.

Salut,
  Mathias