[Elecraft] Flagpole antenna

Mon Mar 17 13:55:01 2003

I think you would be much better off using a remote tuner at the base of the
vertical. Look at SCG or LDG tuners. Also as Vic says the longer the better.

I think you can buy a fiberglass flagpole and run a wire or maybe a run of
1/2" plumbing copper up the center?

GL, pete
kn6bi

-----Original Message-----
From: [email protected]
[mailto:[email protected]]On Behalf Of Vic Rosenthal
Sent: Monday, March 17, 2003 9:03 AM
To: [email protected]
Cc: [email protected]
Subject: Re: [Elecraft] Flagpole antenna

[email protected] wrote:
>
> I need a vertical antenna on my lot for a few reasons, and a flagpole
> vertical (flagpole being the radiator, not housing it) seems to justify a
lot
> of those reasons. Force 12 currently has a special on their flagpole kits.
> Size is about 15.5 feet of flagpole,longer if needed. Does anybody have
> experience with these type of antennas?  It will be for my K1.  It will
> strictly be for 40,30,20, and 17meters strictly CW, strictly QRP.  Will
the
> KAT1 (K1 internal tuner) be able to tune such a load? Any other vertical
> recommendations?

I haven't seen this particular antenna in the flesh, though I looked at it
on
their Website.  Based on this, I would say the following:

1) The antenna's performance will be very dependent on the quality of the
radial
ground system that you can install.  I would shoot for a minimum of 16
radials,
each one 16 feet long.  If you can install 32 radials each 25-30 feet long,
that
would be significantly better.  Follow Force 12's instructions about the
placement of the coax balun.

2) The antenna is somewhat short for 40 meters.  Force 12 mentions an
extension;
a 25 foot vertical would be much better on 30/40.  Remember, if you are QRP
you
need a better antenna than the QRO guy!

3) The antenna is just a vertical with no matching circuitry, so it will
show a
high swr on some bands.  Therefore, I suggest that you feed it with RG8/U to
reduce the loss, even though you don't need the power-handling capability.
The
KAT1 will probably match it on all bands.  If it doesn't, just change the
length
of the feedline a bit.  The shorter the better, again to reduce loss from
the
swr on the line.

Regarding other verticals: Force 12's 5-band vertical dipoles are small,
efficient, and expensive.  They do not need a buried radial system.  The
FluidMotion BigIR vertical does require a ground system, but would be
unbeatable
with a good one.  It's also expensive.

Good luck.

Vic K2VCO
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