Sitting on the roof, contemplating my dilemma, I suddenly
recalled that trapped verticals used capacity hats.  Crawling over
to my home brew 5 element 6 meter beam, which I had recently
removed from the tower and left laying on the roof, I plucked off
two elements.  Quickly clamping these 2 aluminum elements in an X-
formation to the top of my vertical, I dropped the entire assembly
- now looking like a giant TV antenna - back down inside the 24
foot vertical mast and tightened it down.

     Hurrying to the basement, I once again tried to load the
antenna.  It worked!  It resonated at about 1815 KHZ.  Playing
with various lengths, I was able to raise the resonate frequency
enough to allow me about 50 KHZ of room before the SWR became too
unreasonable.  My capacity hat was over 9 feet in diameter but
without it, the antenna would not resonate.

RESULTS

     Just because an antenna can be made to resonate, does not
mean it will radiate.  I have made 3 feet of coax laying on the
back of my desk resonate but could not talk across town with it.
This antenna, however, worked; and worked well.

     I finished my antenna project in early May and operated
almost nightly until mid July when I pulled down everything to
move to a new location.  I made dozens of contacts during this
period of time and worked both East and West coasts often.  On
sideband, I often received reports of 10 and 20 DB over S9 from
W5, W6, and W7.  Although the summer time conditions from Colorado
are not the best for working the East Coast, do to high static
levels, I worked a few, none out of the northeast however, with
reasonable reports on the better nights.  Most think that 160 does
not propagate during the summer because of the low frequency.
Although this is certainly not true, you better plan on getting
used to listening to the static.  Interestingly enough, the static
level is almost nil a few minutes before sunrise each morning and
the band goes long during that window opening.

     I found that the top loaded vertical is one of the most
commonly used antennas on 160 meters and often are only 30-to-40
feet in total length.  Simple 30-to-50 foot telescoping masts are
often used for the vertical element which can be easily purchased
from most radio and hobby stores.  Capacity hats range from 3-to-
10 feet in diameter and sometimes even greater.  A friend of mine
in Texas has used 22 foot diameter cap-hats when using short
verticals under 40 feet in height; thus getting as much signal
above ground as possible.

GROUND SYSTEMS

     On 160 meters the greater your ground system, usually the
better your signal.  This, however, is perhaps the greatest
benefit of the top loaded vertical for the Top Band.  I have
worked hams on 160 who have been using 40 foot push-up masts and
5 foot diameter capacity hats with no more ground system than a
single short ground rod driven in at the base of the antenna.
Some use nothing more than a wire running over to a nearby cold
water pipe.  Top loaded verticals simply work well with little
ground and signals from such antenna compare well with the larger
base loaded antenna - shunt fed towers with large ground systems
for example.

     There seems to be one additional advantage to a short top
loaded vertical on the Top Band over many other antenna.  Because
of its size, it has reduced signal capture area.  This means, in
high static conditions, the shorter antenna often is able to hear
the weaker signals, - perhaps do to the fact it is less resonate
at the static frequency - compared to shunt fed towers for
example.  I know some will take issue with this statement, but I
have personally observe this to be true.  Many times, when
comparing incoming signals with local stations using larger
antenna who have not been able to copy a weaker signal, I have, on
the other hand, with the shorter antenna, been able to hear and
copy clearly.

                           CONCLUSION

     If you have a 160 meter position on your transceiver, now you
can try it out.  In recent years, the top band has become more
popular with hams who have discovered that short antenna indeed
work well at low frequencies.  Of course, the winter conditions
are the most favorable for 160 meter communications, but you will
find even the summer to be good for under 1,000 miles.  An
amplifier certainly helps on any band, especially during the
noisy summer time, but I have no problem working the western half
of the U.S. from Colorado even with 100 watts.  If you want to try
the top band but are short on money, space, and tower; try the
short top loaded vertical.  You won't be disappointed.


Phil.
K0NX
Echo Link: 145 280