[SixClub] Back on the list

[Mike (KA5CVH) Urich]

On 3/12/06, W9FS - Jerry <sixclub at 6mt.com> wrote:

So if you have a power line that is radiating noise or even a TV that
is say 20db over S9 you have no way of tuning out the interference
with an omni, but with a beam you can.

Mike wrote

Yes the gain will be similar enough that aspect should not be a matter
of consideration but there are two other factors that I didn't see
discussed.   I understand most of it but don't always properly spit it
back out correctly so forgive me if I misspeak.

The first thing is;
What are you trying to use the antenna to achieve?  By that are you
wanting to work mostly north American (NA) stations or are you trying
to make transoceanic (TO) hops as well?

The first reason I ask this is because I didn't see anyone address the
vertical angle of radiation.  I have no idea what kind of vertical
pattern the stacked KB6KQ's would exhibit but I bet it is much broader
than a yagi.  This should serve you well for NA contacts but I suspect
poorly for TO.  The second reason I ask is what Jerry alluded to and
that is the stacked omni's will have _NO_ ability for rear rejection
which is important when trying to pull a weak one out.

So IMHO gain is not the only thing you need to be concerned with.  You
need to evaluate how important vertical angle of radiation is and
whether or not a good front to back ratio is needed.

Now to whether or not to spin a beam (presumably a yagi) with a TV
rotor.  I have seen good tv rotors and I have seen "puny" tv rotors. 
A good TV rotor should handle a 3L yagi _AND POSSIBLY_ a 7-10L 144
yagi as well but you are really stretching the limits here.  I did a
google search for antenna works and found a web-site
http://www.antennaworks.com/ but its only about RF amplifiers.

As always YMMV

Mike Urich KA5CVH
http://ka5cvh.com
Amateur radio ~is~ a contact sport