in the last times the telescopic whip antennas appear on the summits, The possiblility of make contacts with a 1.4 meters long antenna and without deploying a mast and 20 meters of wire is interesant, of course.
I own from long time ago a MFJ 1840T that never use until this new 25 cicle, with correct results. Then I use too a 27mhz whip BNC for 28 mhz with a lot of transatlantic QSOs, incredible!
I am looking for another with for 14mhz but I don´t want to pay something like Elecraft AX1, sorry…
We arrived at this point to build a prototype od 14mhz whip BNC for my FT-818.
The total ammount of this proyect is below than 5-6 euros.
I have been experimenting with short HF dipoles for use in high altitude WSPR balloons in the last few weeks.
The image shows two coils each at the base of 1m of wire “whip”. This one was for 10m but I also made one for 20m. The coils just had more turns. This is just an experimental rig, the final one will be much more compact.
The 10m version was heard in Tenerife with just 9mW of power from the transmitter. Distance approximately 2500Km with the antenna 5m off the ground.
The 20m version was heard by more stations but only up to 1000Km, shown in the WSPRnet screenshot.
I’m still working on the design but these short antenna do work.
