The AM Forum

A digital signal has been the talk of the 75M band for some time now, particularly among AMers in the Northeast. It has the characteristics of a STANAG (Standard Agreement) data transmission of the type used by NATO and has been particularly noticeable over the past year, which would be no coincidence.

While the noise is centered on 3870, it seems likely to be an "8-PSK" (8-Phase Phase-Shift Keying (3 bits per symbol)) USB signal on 3868.5 kHz with a 3 kHz bandwidth. Browsing some European SDRs yielded some interesting results (see attached image).

The Kiwi SDR in Svenes, Norway had the strongest signal strength (see attached image):

http://109.247.21.63:8073/?f=3870.00amz10

There were plenty of receivers with FB reception for a TDoA scan although it took several tries to isolate and remove a trouble maker receiver that was creating a parabola error. The best representative of the most consistent heat maps is attached.

Not that this resolves anything, but at least it shows the ability of a first-world military to generate QRM. I also have no ambitions of getting a reception report from SWLs in Norway.

Greta Thunberg needs to be made aware of the energy being used by this operation!

Greta needs to be made aware of pretty much everything. I do agree with her on one point: she should indeed have been in school.