Hamstick dipole for 80m
Jouko,
I had the same problem, despite assurances from the wholesaler in the USA
where I bought the the two Hamsticks, they were resonant at their lowest at
3750 kHz. I needed to operate them at a lower frequency of no more than 3650
kHz
I tried extending the stainless steel "stinger" but I couldn't find anything
long enough.
Then I tried a disk of aluminium 1.6mm x 75 mm in diameter, fitted between
the stainless whip and the antenna proper, and that reduced the resonanant
frequency to 3575 kHz, adjusting the stinger length was necessary of course.
You may have to make the diameter of the disk slightly larger to get it to
resonate at the lower frequency, just a matter of cut and try.
Using my MFJ Analyser, the feedpoint resistance was close to 50 ohms.
It was a very simple fix!
73
John VK2KCE
"JN" wrote in message
...
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
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