Dualfeed with 2,4GHz Helix-Antenna

thingiverse

This Dualfeed is designed specifically for use in an offset dish to communicate through the first geostationary amateur radio transponder from Qatar (QO-100). The Dualfeed consists of a holder for the Helix-Antenna and a LNB mounted behind it. The holder is simply attached to the 40mm body of the standard LNB. I have saved a suitable LNB, SMA socket and screws in a shopping cart (many other LNBs will fit as well). The reflector for the Helix-Antenna is made from 0.5mm aluminum sheet with the help of the Helix_marker. It's not recommended to use beer can sheet metal due to its sharp edges - although it might be possible without causing harm. To form the enamelled copper wire of the helix, wrap a 38mm tube with the appropriate pitch or simply use the Helix_former. As a weather protection cap (unfortunately not permanently uv-proof), I used a yoghurt cup from the discounter. I eat yoghurt regularly and have many weather protection caps as replacements. If the cup needs to be painted, check its RF suitability in the microwave oven. Notice: The helix must be adjusted according to your offset dish (download the enclosed Excel calculation). The Dualfeed may not match your center feed parabolic antenna! Adjusting the Helix-Antenna with an antenna analyzer is unfortunately unavoidable. Tools that were used additionally include a stand drilling machine, VNA (N1201SA), soldering station, hot glue gun, tin snips, stepped drill, pliers, side cutter, files, hammer, nails, screwdriver, drills for 3mm and 6mm, and a knife. 73 es 55 de DH1ND... and I hope to hear from you soon via QO-100!