intermodulation 3935 AM 0921 UTC 26 Oct 2021

[Ray Lalleu]

on 3935
0921 very weak on Twente Weston SDR, (not at home)
talking, background music, sounds like two stations (or intermodulation ?), 0928

edit : there are intermodulation products on the Weston SDR around 3900. Those intermods are from powerful stations around 17600 and around 13700, so the difference is around 3900.

Example around 1230 UTC: China in French on 17560, unknown in Arabic on 13635,
and the mix of sounds is on 3925 kHz.

Such mixes sometimes happen inside a transmitting station, but that seems not the case.
At the receiving location, it can be anywhere on the antennas and receiving devices. It could be on any other wire or fence with a bad contact if the signal are really huge. But most likely in the amplifiers, or in the SDR sampling stage.