25 May 2011
As an example of just how strong signals can be on 10m with strong Es conditions take the reports this afternoon from DJ0ABR. With 500mW to my halo he was giving me a WSPR report of +7dB S/N. This suggests I'd still be OK with just 500uW from the transmitter. I know others have achieve far better than this but it does remind you that a big sporadic-E "cloud" acts as a very good mirror.