You can use this with the default antenna supplied with most of the cheap dongles.
The GPS L4 signal shows up as a visible spike at 1379.913MHz. The bandwidth in that area is uncluttered, to prevent interference with GPS signals. If using SDR#, enable the IF display window to get a close-up view of the spectrum. Adjust the PPM setting to align the spike as close as possible to 1379.913MHz. It's pretty easy to get an alignment to the nearest PPM, which is close enough for pretty much anything.
It's easier to get an accurate calibration with this reference than using TV stations or other lower-frequency broadcasts.
The GPS L4 signal shows up as a visible spike at 1379.913MHz. The bandwidth in that area is uncluttered, to prevent interference with GPS signals. If using SDR#, enable the IF display window to get a close-up view of the spectrum. Adjust the PPM setting to align the spike as close as possible to 1379.913MHz. It's pretty easy to get an alignment to the nearest PPM, which is close enough for pretty much anything.
It's easier to get an accurate calibration with this reference than using TV stations or other lower-frequency broadcasts.