qo-100 helix antenna

thingiverse

Relatively easy to build QO-100 uplink helix antenna for the hamradio 13cm band (no satellite dish required). This antenna is good enough for QSOs in SSB (SNR 13 db on the websdr). For the downlink you can listen to a QO-100 websdr. Building instructions: - Print the helix reflector and use double sided sticky tape to fix aluminium foil on it. - From the hardware store buy 10mm width square tube for the antenna boom and 3 mm copper wire for the helix. I used 15,5 turns. You can add some more turns, but more than 20 is not effective - as i read. The distance between turns is 30mm. The outer diameter of a turn is 42mm. The tube of a vacuum cleaner with 35mm diameter could be a winding help. Be sure the helix is clockwise (right hand grip rule), like on the photo. That is different to a helix used with satellite dishes. - A N-connector can be the antenna socket put directly on the reflector. - Some brass tube can be used as connection between socket and and helix. This material is much easier to solder to the socket than the realtively sick copper wire. - Print some of the helix mount parts to center the square tube in the helix. - Print the arc part to have a fixed elevation of 27 degrees to the QO-100 satellite in case you want to mount the antenna on a (wooden) board. Print with PETG infill 40%