There’s even a zero ohm SMT resistor that could be repositioned slightly to feed RF to the UHF jack. A little work with a soldering iron and [Brian]’s Pi was connected to an external antenna.

integrating VHF/UHF, cellular, GPS, LTE, 3G and 4G as compatible arrangements to minimize co-site interference. Dual-mount bi-directional antennas. Omni-directional antenna. MIMO vehicle antenna.