Nice explaination,,

I understand it a lot better now, I like your idea of the off centre
advantages especially when the tree distances are off,
should work out ok, unless I cut one of my neighbor's tree,,,, might look
too planned.

Any good ideas for a homebrew omni on the top of the 50ft tower?

I also have a couple hd antennas I must get higher, the dish is on there but
lower.

I would like to put a whip on the top mast, half way down the masting put
the two hd antennas for tv ( I figure one aiming north, one south (my
local's station most direction)) then tee that up then there at the top of
tower tie in a OCF dipole towards two trees.

The chap at the electronic store who sold me the hd antennas said it is
better to do it this way or to have the router. Any body confirm or deny
that? only a hundred bucks worth of parts there so not much but great signal
and high def.

thanks again for your experteeze on the topic, my plan is to minimize the
climbing.





"Dave Platt" wrote in message
...
What about the dipole? I have a 1:1 balun and both ladder line and coax.
Which is prefered?

If you want to work a wide range of bands with a single center-fed
doublet, I think you'll have more success using ladder-line, and
feeding directly from the balanced output of your tuner. If your
tuner has only a non-balanced (coaxial) output, I'd suggest using a
1:1 choke (current balun") as close as is practical to the tuner
output, and then transitioning over to ladder line.

If you're using coax, and a balun at the top, you may find yourself
suffering from significant losses in the coax at high SWRs. Using
ladder or open-wire line, with its higher characteristic impedance,
can reduce these excess losses quite a bit (although not entirely
eliminate them).

Are you firm about using a center-fed doublet/dipole? A number of
people I know are very positive about their "off-center-fed"
dipoles... these can work as coax-fed antennas (using a 4:1 or 6:1
balun at the feedpoint) on a set of harmonically-related bands (e.g.
80/40/20/10). Another option here is to use an off-center-fed wire,
but feed it with ladder line (no balun at the feedpoint)... gives even
more band coverage.

These OCF antennas are typically fed at a point around 2/3 of the way
along the length (e.g. one arm is around twice the length of the
other) and are cut to a length which is halfwave-resonant on the
lowest band being used.

An example is the Alpha Delta DC-OCF - 135 feet long (legs are 45 and
90 feet), 6:1 balun at the feedpoint, coax-fed, covers 80/40/20/
17/12/10 meters "No tuner required". It covers the lower end of 6
meters pretty well, and the higher frequencies with an increased SWR
("use with caution", presumably to avoid overstressing the balun and
transmitter).

Most of these doublet/dipole antennas can also be treated as a
top-loaded vertical, and fed Marconi-style (short the two sides of the
feedline together, connect to the "hot" side of the tuner, and feed
the ground side of the tuner to a good bed of radials). This can let
you work lower-frequency bands (e.g. 160) on an antenna that by itself
is too short to load up properly at such a low frequency.

--
Dave Platt AE6EO
Friends of Jade Warrior home page: http://www.radagast.org/jade-warrior
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