>Well, the only place I have to bring the coax and rotor cables from the =
>roof to the second floor (where is located my apartment) is the same =
>place where the 75 ohms antenna tv cable passes. Does anyone have =
>experienced the same situation? TVI will happen for sure? The antennas =
>(my 2 el yagi, the VHF tv antenna and the directv dish) are very close =
>up there anyway. The only place available to install antennas on the =
>roof is an area of 24 ft x 12 ft.=20
>I am asking that (and do not try directly) because the cable will show =
>up in the main room and I will have to break the floor or the the wall =
>to bring the cables to the shack. Big work... big problem with the wife. =
>If TVI is sure I will have to start again the lobby work with the =
>neighbors to pass the cable outside the building (this second option is =
>hard to accomplish).
>I would like to hear some comments.
With the exception of VHF instead of UHF, what you describe is
along the lines of my current & past two QTHs - top of three floor
reinforced concrete house, each floor an separate flat & all
antennas confined into about 5 x 9m of roof area.
I do nothing special, other than common-mode chokes on all lines at the
base of my roof tower (because it is also shunt fed for LF bands).
Even before shunt feeding the tower, I did nothing special. I find that
anything coming down the feeders pales in comparison to the fact that
everything - terrestrial & satellite antennas, not to mention the telly &
satellite receivers inside the flat - are anywhere from 3 to 5m away from
the feedpoints of my antennas.
I probably have more RF inside the shack being re-radiated by the mains
cords of devices plugged into the ring main than what would come down
Go for the same entrance & save your energy for trying to tame the other
things you are likely to have to deal with no matter how you route the