Since the stock antenna was not cutting it, he decided to make one specifically for the 1090 MHz signal. His design is based on Coaxial Collinear Antenna for ADS-B Receiver by [Dusan Balara] which ...

1/4 wave, 26.5-30 MHz, Unity gain, 49" whip, DC ground, shut fed base load, gold plated plunger type contact pin NMO Trunk Antenna Mount with 17' Coax Cable, PL259 type assembled connector ...