Homebrew GPS Antenna Notes

Plan: reproduce the quadrifilar helical antenna shown with the Trimble 4000S in a number of promotional photos:

Diameter: probably 4”

Dome Height: 4.25”

Flange: 5.4”

Flange Thick: 0.1”

Screw Head Diameter: 0.29” (6-32 = 0.270”)

Vaisala RS80-15GH

quadrifilar

http://jcoppens.com/ant/qfh/fotos_gps.en.php

http://lea.hamradio.si/~s53mv/navsats/analog.html

https://electricajournal.org/Content/files/sayilar/63/1.pdf

https://forums.overclockers.com.au/threads/diy-qfh-antenna-for-gps.1163180/