20m short

20m T-Monopole - 20m T-Monopole short vertical antenna for 20 meters by AA5TB

40 meter shortened dipole - M0MCX - Interesting little project with a couple of loading coils by M0MCX

40m & 80m portable wire antenna - G8ODE antenna project, where the 40m & Short 80m antenna was deployed as a sloping wire antenna using the 10M fibre glass fishing pole and a hook on the house's gutter-board

Vertical antenna for Vacation - Vertical Vacation Antenna for 80, 40 and 20 Meter-Band, by Herbert OE3BMB This antenna is a full size λ/4 for 20m and 40m band, and a shortened λ/4 for the 80m band. Generally on the 40m band the SWR is under 1,6. In 80m and 20m band at the resonant frequency the SWR is about 1,1.

WebSDR on 20m, 40m and 80m  ^pop - On this page you can listen to and control a short-wave receiver located at the amateur radio club ETGD at the University of Twente. In contrast to other web-controlled receivers, this receiver can be tuned by multiple users simultaneously, thanks to the use of Software-Defined Radio