I purchased a used Force-12 C3 in the fall and was planning on replacing
my 4 element 5 band quad (10-20) in the spring. When a director wire
came unclipped, I decided to lower the 50 foot tower and replace the quad
prior to the recent ARRL DX contest. The C3 was partially assembled, and
reassembled very quickly. We had a mild day and the swap went quickly on
the Saturday before the contest.
Sure enough even with QRP, the C3 worked just fine, and a bunch of
contacts were made. I use the antenna at 55 feet for chasing multipliers,
while my stack of a TH6/TH7/TH6 at 90/60/30 feet is used for running Europe
most of the time.
I managed to beat all the locals at one time or another in the packet
pile ups, mostly to stations in the Caribbean and in South America.
On long haul and big African piles, I usually used the high pair of
antennas, which out performed the C3 and the old quad.
Anecdotal, I would have to say that the C3 was just fine, at least in the
CW pileups.
Now for the real world comparison between the C3 at 55 feet and a TH7 at
60 feet. These antennas like my old 4 element quad are very close
together on separate towers. I suspect that the TH7 has less
interference from the C3 towards Europe and visa versa towards the
west. In ALL directions the TH7 tends to appear to hear almost an
S unit better. Perhaps there are feed line differences, although
both are fed with hardline and the TH7 had a relay and 60 feet of RG 8
at the end of the hardline. The C3 claims about 10 db front to back,
and that seems about right. The front to side is, of course, NOTHING like
the 4 element quad. (which was rarely better than the TH7 in any direction
as well) As K3OX, who helped me put it up and run the comparisons, said
"they haven't broken the laws of physics."
Am I happy with the C3? So far yes. The big quad was too sharp for quick
multiplier grabbing, I often lost out by pointing at the wrong island down
south. The pattern and f/b of the C3 does about what I need for what I
want it to do, it's very tidy and easy to handle, and would be easy to
travel with. I will not be replacing my stack of TH6/7s with C3's.
If I could have but one antenna it would be the TH6/7 or perhaps a
2 or 3 element quad (could do WARC bands then) The 4 El quad is neat for
DXing, but too sharp for my type of contesting. The KT34XA is probably
a tad better than the TH6, but I had a KLM 40 down 4 or 5 times one winter
and when I think of ICE and those end loading devices, I just can't go with
it. On the other hand local guys have had minimal problems with the KT34
class antennas.
If someone had told me that I could make 2300 Qsos with a tribander based
station, back in the 70's when I had Monobander stacks all over the place,
I would have been skeptical. If they had said it was possible during a
sun spot minimum, I would have known they were crazy.
Knowing what to expect from your antennas an taking advantage of your
strengths is one of the key elements in contest success. Improving
on your limitations of course is the fun part of station design.
73 de Chas
k3ww@fast.net
http://www.users.fast.net/~k3ww
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