At about 1545z, I turned on the PA on my 10m WSPR TX beacon. Immediately, spots of me were received, so the 30dB power difference is very significant. I guess unless the local noise level is very low, stations struggle unless propagation is very good.
Until the Es season, I do not propose to try 500uW WSPR on 10m again. I shall stick with 500mW. During the Es season I may well try 500uW again.
23 stations have spotted my 500mW 10m WSPR TX .