It's not just the antenna, it's also the feedline and the space at (or
near) the top of one's tower.
How many 2 meter ringos are still up there collecting oxidation from the
days of packet and when people actually cared about VHF repeaters? How
about a campaign to replace them with some sort of horizontal polarization 2
omni meter antenna, to go with your 706, 746, etc.?
Also a no brain add on six meter yagi kit - probably 3 elements - that
could be added onto the boom of an existing tribander or monobander? Could
someone come up with a diplexing system that could let such a six meter
antenna piggyback on the feedline of a lower frequency yagi? Ultimate
performance on six not essential, but just good enough that it would not
greatly
affect the lower frequency antenna's performance or matching.
73 - Jim K8MR
In a message dated 3/6/2010 4:14:18 P.M. Eastern Standard Time,
ezimmerm@erols.com writes:
Dave
No doubt a VHF tribander would be a great boon to VHF activity. As far as I
know only one was ever marketed. Ariane, the company that took over C3I
when
Owen Wormser retired, had one on their books. It was about 15 feet long but
was not cheap - in the $300 range or maybe more - I don't remember. I know
who designed this one and his antennas work so I assume this one would have
worked. Unfortunately Ariane succumbed to high aluminum prices soon
afterward so we have no way of knowing.
Costs are not trivial because I'd guess it took some real engineering to
make all three section work independently and aluminum costs are
unpleasantly high.
The first homebrew HF tribander I ever saw was designed by my mentor, Len
Chertok W3GRF, and had 2 el on 20 3 el on 14 and 5 el on 10 in line. It was
around a 36 foot boom and was designed empircally there being no modeling
software available in the 1950's accesible by hams. It gave a very good
account of itself and I suspect that a VHF in-line tribander might work
with
very little interaction between the bands. For the experimenters I would
start with WA5VJB 6 el cheap yagi on 2 and an 11 el cheap yagi on 432. That
makes a ~135 inch boom so far. At the rear end I would add a 2 el 6M moxxon
either homebrew or the one from Par Electronics if Dale still sells those.
Even buying the 6M portion I'd bet the antenna would cost less than $150.
If someone designs a tribander, models it and can describe it in 2 QST
pages
I will offer to publish it in the World Above 50 MHz. The key of course is
something that is readily reproducible without tons of test equipment. That
is the primary virtue of the Cheap single band Yagis.
73 Gene W3ZZ
-----Original Message-----
From: David Pruett [mailto:k8cc@comcast.net]
Sent: Thursday, March 04, 2010 8:43 PM
Cc: VHF Contesting Reflector
Subject: Re: [VHFcontesting] Getting beginners interested in VHF Contesting
>From the conversations I've had with non-VHFers, cost is a major issue to
getting on VHF/UHF. On HF you can toss a $5 dipole in a tree, feed it witn
junk coax and work a bunch of people on 80 and 40. As W3ZZ points out,
that
doesn't work on VHF. Most decent VHF/UHF antennas are at least $100, and a
decent low lost feedline is at least $50, depending on how much length you
need. So $150 gets you ONE BAND worth of effective antenna. Joe706 needs
$450 worth of antennas (assuming he has a support for them) just to try
something he might not even enjoy doing. And if he want to get on a band
where he needs a transverter, that's another $400.
W3ZZ and I were discussing this at Dayton last year. I compared this
situation to the 50's, when Mosley or whomever commercialized the first
20-15-10 triband beam. Three bands from a single aerial and feedline,
reasonable cost and manageable size did a lot for activity on those bands.
Where would we be today in regards to contesting and DXing, without the
triband beam?
What we need is somebody to come up with a good 50-144-432 triband antenna
with a single feedline to go along with the IC-706s and the various Yaesu
FT-8x7s out there. If it were commercially available in the range of
$100-$200, that would be terrific. Icom and Yaesu have done a terrific job
with creating 50/144/432 rigs at reasonable cost, now if somebody could
solve the antenna issue as well...
Lacking such an antenna, I think WA5VJB's "Cheap Yagis" are a great way to
get started for low $$$. I'm gonna try to build a few this summer for two
reasons: 1) To see for myself how reproduceable these antennas are, and 2)
to have some antennas I can loan out if any of my "Joe706"
friends wanna try VHF contesting.
Just my $0.02
73, Dave/K8CC
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