Running a spectral purity check on my Icom ID-51A+ DSTAR radio, I found that it passes FCC requirements as you would hope it would.
The test setup used for the UV5R was only slightly modified to change the bandwidth so that the noise floor was lowered. This uncovered a spur that is in the SA itself, at 344.8 MHz (#2 in the photo below). Since that is not coming from the UUT, it can be ignored.
The power from the ID-51 was -3.48 dBm + 40 dB for the external attenuator = +36.52 dBm = 4.49 watts.
The worst case spur the third harmonic at -68.15 dBm, which (adding back the 40 dB from the external attenuator) is -28.15 dBm or 1.5 microwatts. It is also 64.7 dB below the carrier.
