Just purchased a (tri-band 2, 1.25, .7 meters) Kenwood TH-F6A HT and was
wondering what I should use for a base antenna that will be over 60ft high
(bet I'll get tons of intermod). One thought is to purchase the best
tri-bander available or, perhaps there is too much compromise with an
all-in-one. Would you use a dual bander and a mono, which band is the dual &
which the mono or 3 monos? Of course with anything other than a tri-bander,
a triplexer will be needed. Oh what trying decisions a ham must make! Any
comments most welcomed.

73s
west
AF4GC

On Wed, 01 Mar 2006 22:21:10 GMT, "west"
wrote:

what I should use for a base antenna that will be over 60ft high

Hi West,

A simple tribander should be able to hit a similar tribander, or at
least a quarterwave just as high 20 miles away. Repeaters should be a
breeze to hit unless you are DXing garage repeaters. I can't see that
you need more gain nor complexity unless its to make up for line loss
climbing that tower. In that case, add a brick amplifier at the input
to the line.

73's
Richard Clark, KB7QHC

west wrote:
Just purchased a (tri-band 2, 1.25, .7 meters) Kenwood TH-F6A HT and was
wondering what I should use for a base antenna that will be over 60ft high
(bet I'll get tons of intermod). One thought is to purchase the best
tri-bander available or, perhaps there is too much compromise with an
all-in-one. Would you use a dual bander and a mono, which band is the dual &
which the mono or 3 monos? Of course with anything other than a tri-bander,
a triplexer will be needed. Oh what trying decisions a ham must make! Any
comments most welcomed.

73s
west
AF4GC

If I were dead set on all 3 bands, I would use a seperate ground plane
antenna for each band, and an antenna switch. The ground planes are
small.
Gary N4AST

In my experience a super antenna for repeater operation is a problem.
You bring up enough machines to create your own QRM. Keep it simple.

On Wed, 01 Mar 2006 22:21:10 GMT, "west"
wrote:

Just purchased a (tri-band 2, 1.25, .7 meters) Kenwood TH-F6A HT and was
wondering what I should use for a base antenna that will be over 60ft high
(bet I'll get tons of intermod). One thought is to purchase the best
tri-bander available or, perhaps there is too much compromise with an
all-in-one. Would you use a dual bander and a mono, which band is the dual &
which the mono or 3 monos? Of course with anything other than a tri-bander,
a triplexer will be needed. Oh what trying decisions a ham must make! Any
comments most welcomed.

73s
west
AF4GC

John Ferrell W8CCW

On Wed, 01 Mar 2006 22:21:10 GMT, "west"
wrote:

Just purchased a (tri-band 2, 1.25, .7 meters) Kenwood TH-F6A HT and was
wondering what I should use for a base antenna that will be over 60ft high
(bet I'll get tons of intermod). One thought is to purchase the best
tri-bander available or, perhaps there is too much compromise with an
all-in-one. Would you use a dual bander and a mono, which band is the dual &
which the mono or 3 monos? Of course with anything other than a tri-bander,
a triplexer will be needed. Oh what trying decisions a ham must make! Any
comments most welcomed.

West,

Some thoughts:

The economics of feedline(s) might tilt the solution in favour of a
single triband antenna with LDF4-50 or better, though you will
probably want a very short flylead to the handheld. (Note that the
loss in 100' of RG213 at load VSWR=1.5 is 5dB at 70cm, whereas LDF4-50
is 1.5dB, and the loss in a 5' tail of RG58C/U under similar
conditions is 0.7dB.) If you only want to work repeaters and your path
is good enough, losses might not be an issue. (Remember though that 5W
handhelds get really hot on full power.) Is LDF4-50 overkill for a
handheld? It might be more appropriate than with a higher powered
transmitter.

If intermods are an issue (as handhelds have less than adequate front
end selectivity), do the repeaters use CTCSS... at least that helps
prevent the transceiver breaking mute all day and night. Does the
radio have a real rx attenuator that can help with intermods, to you
have sufficient rx signal strength to be able to use it?

At least you are not intending using a discone. Handhelds rarely work
well on external broad antennas (for intermod reasons), and even the
multiband antennas can be a challenge for handhelds.

Owen
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