On Tue, 25 Mar 2008 14:05:13 +0200, "JN" wrote:

Hamsticks and their clones are for US 75m (4MHz) and not directly tunable to
80m (3,5 MHz)

I plan a Hamstick dipole for Digimodes and CW for say 3560 kHz.

What is the best way to lower the resonance frequency
Some type of capasitive loading at the end of base(coil) section
or an inductance at center wich could maybe also function as impedance
transformer?
What is the feedpoint resistance of Hamstick dipole?

Any ideas or experiences?

73 Jouko OH5RM


The ham stick dipole isn't very great for 80 meters. I know from
experience that the hustler mobile antenna works better than the ham
stick on 75 meters. I have used the ham stick on 80 meters mobile
with an antenna tuner. The antenna tuner gave me a much broader
bandwidth as far as SWR is concerned without having to retune.

On the other hand, you are not operating mobile. I don't know how
this compares. I know when I did it, it gave me a very weak, but
readable signal. I had a ground rod in the ground below my window. I
connected the shield side of my coax to the ground stake and the
center to one end of a long spool of wire. I stretched the wire out
about 1/4 wave on the ground and checked the SWR. It was flat on the
frequency I wanted (I got lucky) so I checked into the then GA SSB Net
on 3975. I was weak, but readable and could pass my traffic.

If you can make loading coils, make a couple with large diameters.
The larger the better. Center load each element and make them so you
can tap to the coil. This will work better than the ham stick. You
may find that tapping at two different points works better for you so
you have a bit of an offset in the electrical lengths of the antennas
on either side of the coax. This is because the impedance of a
shortened dipole antenna is lower than 50 ohms. The offset finds a
better match.

Hope this helps.

Buck
N4PGW
--
73 for now
Buck, N4PGW

www.lumpuckeroo.com

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