"JN" wrote in
:

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


Hi Jouko:

I ran a “ham stick” dipole for a while and was able to compare it to a
full size dipole when I put one up. To compare the two antennas, a “ham
stick” dipole at 25’ verses a full size dipole at 35’. On 80/75m the “ham
stick” was down about 20db from the dipole. The 2:1 SWR bandwidth was
about 65KHz for the “ham stick” verses about 200+Khz for the dipole. The
way to get a “ham stick” down the bottom of 80m is to lengthen the whip
that sticks out the top. I can’t remember how much but it was not much.
The Z of a whip of the length of a “ham stick” should be only a few ohms,
but they are close to 50 Ohms when used as a dipole. The difference
between 50 Ohms and the modeled 2 to 3 Ohms is the loss in the coils.
The long, small diameter coils made with small gage wire cause most of
the loss. The “ham stick” dipole is better than no antenna but not by
much on 80m. As you go up in frequency the performance of dipoles made
out mobile antennas improve. On 40m my “ham stick” dipole was 12db down
from a full size dipole and on 20m and above it was less than an S-unit
down. Note that I’m talking about dipoles made out “ham sticks” made for
the respective bands, not using a tuner. Using a turner is a waste of
time as you move farther away from the center frequency the loss goes way
up and your signal goes away! I still use my 80m “ham sticks” but not as
dipole. I have them ground mounted with 4 10’ radials each, spaced 1/16
wavelength apart and feed 90 deg. out of phase. This makes a directional
receive antenna for the DX window on 80m that rivals a beverage antenna.
It makes DXing on 80m fun. The only disadvantage is that unlike a
beverage it only works over about a 65Khz chunk of the band.

John Passaneau, W3JXP