How to hide a Number Station
First of all take a powerful broadcast station. The Voice of Russia on 7340 kHz should do it. Then transmit your message hidden in the lower sideband of the masking station and there you are. 7337 kHz is perfect for the job.

The ordinary punter will not find you and all the agent has to do is turn on the SSB mode and the VOR programme is filtered out. Go back to regular AM mode and the number station is hidden again. See how easy this is here:

E03 Hiding video clip. wmv format 0.9 MB


Legendary "Moscow Mailbag" host Joe Adamov is the voice that helps cover up the spy transmission.