The NiceRF SA818S does not contain a lowpass filter so its 2nd harmonic greatly exceeds FCC part 97 spurious emission requirements.? The SHARI Pi3U Chinese clone AURSINC does not use a low pass filter.? Here is a plot of the RF output at 70 cm.
? AURSINC's newer SR-FRS procuct using the Sunrise Electronics? SR110U module has similar issues with spurious emissions as well as numerous other issues which I have documented
?All Kits 4 Hams products add a lowpass filter to the RF output so that the second harmonic is typically 60 dBc (dB below carrier).? The SA818 firmware restricts operation to the 2 meter or 70 cm ham bands.
Steve-N8AR