I'm relatively new to Outernet/L-band and while waiting for APAC to come back online I have been attempting some of the helical designs elsewhere on the forum. However I'm not yet able to build one as good in terms of SNR as the active patch. Some pictures of my 8 turn attempt - suggestions welcome.. is thicker wire a better option than the copper tape? how critical is the coil diameter (this example is 63mm)..
Also one question - I'm not 100% clear on the the first 1/4 turn. I understand this should be ~2mm above the ground plane but where does the first turn end - 50mm above he feed point, or 50mm above the end of the first 1/4 section (assuming 50mm between coils).. asked another way - does the top of the helix finish in line with the Feedpoint or the end of the 1/4 parallel turn section?