A self-adhesive slot antenna for 70 cm
Credits and Background The inspiration for this antenna came from an excellent workshop led by Richard M0GET at a recent meeting of SEMARC . Additional ideas are from the Kindle book Slot Antennas for Ham Radio: The Forgotten Antenna by John Fortune W6NBC. The aim of this design is a simple antenna that can be stuck onto an outside window, providing vertical polarisation primarily for access to the local repeater on 70cm (FM and DMR). An unusual property of slot antennas is that a horizontal slot provides vertical polarisation - so this makes a much easier and tidier installation than (say) an equivalent vertical wire dipole. Construction Details The materials needed are: Some self-adhesive, conductive tape. I used this 75mm tape from Screwfix, but really any copper or aluminium tape will work, and the width is not critical. A short piece of thin 50Ω coax, terminated with a suitable connector. I happened to find something suitable in my junk box: a short piece of RJ174 already fitte