Power supply noise is generally less than 1% of the DC output. Most radios have internal regulators d as a result the master oscillators have phase noise down 140dBc at 10 KHz. The atmospheric noise level is still 30 dB above most receiver noise levels. Even radios made 50 years ago were more sensitive the antenna base band noise.
I'm not quite sure I understand what you're saying. As I noted in my original post, current transceiver testing is usually performed with lab-grade power supplies. Most hams do not use these types of power supplies - that was the scope of my query - the effect of this wide distribution of power supply types and their associated noise levels.
As to atmospheric noise, this is not usually a facet of testing. As to phase noise effects, these are independent of atmospheric effects.