GAP Gets You Off Of The Ground
- It is interesting seeing the various claims for performance of a
variety of vertical antennas. I happened to take a close look at one
of the multi-band trapped verticals and was struck by the fact that
the first trap from the bottom was the 10 meter trap. This means that
the 10 meter "vertical" is only a short 7ft rod setting on the
ground. The remainder of the antenna sets above it and does nothing
except to provide capacitive loading (top hat). Thus the first 2ft,
which does most of the radiating) sets on the ground (insulated from
it) with a few radials actually representing the ground (other half
of the dipole) in a poor fashion.
The GAP, as pointed out in their adverts, gets the point of radiation
above the ground by several feet and creates its own "other half of
the dipole" with no reliance on lossy low wire count radial screens.
I have also seen an article in a recent QST that showed that a
vertical dipole is far superior to a traditional ground mounted
I was thinking of trying one of the ground mounted verticals but
after seeing the obvious, I would not waste my money.
- Dick :
Very well put!
The key point that lead me to buying a GAP years
ago was as you stated broadband coverage with the lack of traps and
matching transformers". The was important to me as 95% of my operating
While the performance of any vertical is dependent on ground
conductivity out to several
wavelengths, a vertical dipole is less impacted by poor conductivity in
the near field of the
antenna than is a vertical monopole which relies on a ground mounted
I am still a bit amazed at some of the GAP reviews on eHam.
I find it interesting that folks either love the GAP antennas or can't
make them work. I have attributed
the majority of the latter to those folks who can't, don't or won't
IMHO the GAP products offer very good multi-band performance with a
of coax. I have had a Challenger up since 1999 and it has survived
a number of ice storms with no issues and easily fits in my
urban back yard without causing too much grief to my neighbors.
We plan to build a cottage in a few years and I will have lots of big
trees for antenna
supports but you can bet that the first antenna that goes up will be a