GPS antenna plot

I bought an inexpensive GPS antenna on eBay, the requirement was for one that operated from 3-5V to suit both of my GPSDOs. The antenna is mounted in an electrical junction box on conduit above the roof for reliable coverage.

The question was whether the active antenna with 5m of RG174 coax and SMA male connector at A$6 posted was any good.

To map its behaviour, it was attached to a Trimble Thunderbolt GPSDO and Lady Heather used to plot rx signal level over about 30h.

Above is the plot. The pattern is not quite symmetric as there are obstructions in play, in fact some of the dips in performance are explained by specific trees and the roof profile. There is a gap to the south at low elevations, GPS satellites don’t fly there (MEO inclined 55° from the equator) .

Overall, it reaches similar strength at the zenith as other antennas tried.

Overall evaluation, it seems to work ok though the coax is a bit rough.