One of the aims of SOTA is to walk in the nature.
So, a light backpack it’s a must !
One the first opportunity I bought a Montain Topper Radio, MTR-3B wich is a 3 band HF (20/30/40 m ), which weights 124 gr.
Because the MTR doesn’t have an ATU or a SWR meter and I don’t want to carry anyone of those, I decided to make an antenna that fit the objective: Been light!
The search for such antenna endup with the trapped dipole or the linked dipole.
Well…I would have quick band changing: The trapped dipole is the way to go!
Searching for antenna traps was an easy one: Sotabeams pico traps!
When they arrived it’s clear that they deliver. Easy to build and tune. Very light weight: 5 gr each!
So a traped dipole was made. On one sunny sunday João, CT7ABE helped to make all measurements at the local public park. After that, all the welding was redone and a liquid rubber coating was applied.
Another set of tests confirm: The antenna was ready to go!
I used a 6m fishing pole but the last meter (tip) wasn’t used because it’s too thin and doesn’t stand the weight.
The 10.45m is an arbitrary dimension, recognising that the 45 degree angle at the apex wouldn’t be achieved
The details are as follow: