Mike and Doug, thanks for the SIW captures. Glad it's working through another cold day. Right now it's about 0 deg F and heading down. I use 183.575 kHz USB to place the wspr-15 signal at 1610 Hz audio tone center. The software I use is WSPR-X v0.8 r3058. I'm not aware of anything newer. 73, Garry, K3SIW, EN52ta, Elgin, IL