Luboš OK2BVG operates beacon OK0EMW on frequency 505.060 kHz. You can find information about the lighthouse at http://www.mujweb.cz/zabava/ok2kfj. If you want to test your device on this band, you can listen in the evening.
The beacon transmits a CW signal and also QRSS3. I tried it with FT-1000MP Mark-V Field, antenna reduced vertical loop to 80m on an 8-story block of flats. On the recording you can hear CW which was S5 strong for me and the picture shows that the QRSS3 signal was strong on OOO+. Recording in MP3 format .: HERE :.
Send to Luboš SWL report, he will definitely be pleased.