Chuck

Chuck W. wrote:
Is there any major advantage of mounting a Butternut vertical on top of
my house which would put it around 45 feet versus ground mounting it?
Seems like for years I've worked lots of stations with ground mounted
verticals. So long as I've got lots of radials I would have a low
angle of radiation, yes?

Thanks,

Chuck
W1CEW


I have used elevated 4-square vertical arrays and elevated verticals for years
on 40 and 80 meters. Performance seems just fine on them. However one very
serious issue remains, as far as my experience is concerned, for using them.
You, MUST provide some decent lighting protection for them as to how to avoid
the step voltage that appears on the whole system because of the elevated
radial and feed point positions above ground during strikes and even nearby
hits. Even a ten foot height above ground for a 40 meter vertical, with four
tuned elevated radials at that height, is a huge voltage point up from true
ground, considering the large RF currents in the strike. If your feed line is
in any position to be involved in that elevated voltage position and can carry
part of the strike dissapation back into your shack or home, you can really get
hurt.


I found out a long time ago, that the best way to protect my equipment with
elevated HF verticals is to carry the entire feed system back to ground level
where I can incorporate Polyphaser or other gas tube protection at that same
ground level I'm using to sink the strike at the arrays. Then I bring the feed
line back to the physical structure at GROUND level with appropriate protection
at the structure site entrance, sinked to ground as well there.


Since incorporating that technique, for many years now, and I take an average
of a direct hit on my 80 meter array at least once every year or so, I never
have lost anything on the HF station, even though it is on line 24X7 all the
time, and some parts of it are remote operatable as well. With complete pig
iron equipped industrial rack computer systems and so on, even they have
survived completely for years now that way too. But not switching power supply
stuff, as I've found out sadly.


I take more damage, whatever, from direct hits on the neighboring power lines
that sink back to my facility good ground systems, at this point. The worst
damage for years is oddly on the phone system lines. Even with protection at
the entrance point, there is still enough inductace ramp-up on these low level
circuits, that I'll see blown fuses in the phone line protectors from time to
time, and rarely, even yet, modem failures, even with that done!


Again, my best advice if you want to go your way with the big elevated
vertical, is to carefully consider how to mitigate the strike effects for not
only your ham gear, but the rest of the dwelling as well. Remember, even ten
or twenty feet is a real length for getting surge voltage, when true ground is
underneath it. And where things are connected at a junction point which can
carry part of the surge current off on a 'parallel' path to a different ground
sink point you might not have considered.


W5WQN