portable pluggable YAGI Design

I reworked some files, created endcaps and feel like I could publish the first version of the yagi design.

The files now can be found on my github repository: https://github.com/pointhi/oe5tpo_antennas/tree/master/portable_yagi_v1

Please look onto the README.md file, because the models are specific designed for my printer, and probably need adjustances of the tolerances (otherwise the modules wouldn't hold on the rod).

This is how the new designed endcap looks like. Now a fully assembled antenna looks pretty professional:

I finished my second yagi antenna using this quick lock system.

It's a 4 element yagi for 2m, with about 7dB Gain (Design from DK7ZB: http://www.qsl.net/dk7zb/PVC-Yagis/4-Ele-2m.htm)

Furthermore I improved all 3D-Printed-Parts, to fix some issues like to thin walls or to little mechanical stability of the radiator. The rewrite also helped me to cleanup the project, so I should be able to publish it soon.

I verified the design by receiving Delfi-C³ in a distance of about 1500km. I heard either the CW Baken, or the BPSK Telemetrie downlink on 145.870 MHz, using a UV-5R as receiver.