There's a good chance that this transmission comes from a completely different transmitter / location, and it is just on the same frequency as the Russian trans

There's a good chance that this transmission comes from a completely different transmitter / location, and it is just on the same frequency as the Russian transmitter. You can do this with amateur means (a simple dipole antenna and a amplifier in the low kilowatt range, plus a SDR to generate the signal); in fact many radio amateurs are already equipped to do this at any time. Here's some background on the "spectrum painting": https://www.rtl-sdr.com/tag/spectrum-painter/ https://www.rtl-sdr.com/tag/spectrum-painter/