Hearing Radio Saudi (BSKSA Holy Qur`an Riyadh transmitter, 500kw) on 11820 SIO 555 with S9+10 signal strength and WRMI (Overcomer Ministry / Brother Stair USA Okeechobee Florida transmitter, 100kW) on 11825 kHz SIO 555 with S9+20 signal strength heterodyning the hell out of each other.
Interesting to hear two powerhouse religious broadcasters going neck-and-neck on adjacent frequencies. Listening to 11825 kHz shows considerably worse interference from 11820 kHz, indicating that Radio Saudi is transmitting a wider signal. I'm sure the 400 extra kilowatts helps too.
I checked several remote SDRs around the USA and on the East Coast of the US. One can watch the WRMI signals match up on the waterfall - easy to compare 11580 kHz (another strong WRMI signal) and 11825 kHz.