Signal jamming on 7.450 AM

[sean_kd4adv]

There is a warbling sound of a digital signal on 7.450 MHz AM that is covering an English speaking program right now. I am reading an S-9 on the radio's meter.

 

[w2xq]

It may not be jamming, just propagation. Don't forget about the 3 ITU regions. The 40/41 bands have different usages.

 

[Boombox]

Don't rule out RFI.

Whenever I hear 'warbling' near a broadcast signal, that's generally the first thing I think of.

I have several devices whose switching power supplies / DC-DC converters, etc. put out weak signals in various places in the SW spectrum.

 

[k9rzz]

^^^ Agreed. Although it looks like China is on that freq. When was this and was it a Chinese broadcast or Greek?

 

[gpsblake]

7454khz and it's been there for months (if not longer) and it interferes with WRMI's transmission on 7455.

 

[k9rzz]

Is it teletype?

 

[Token]

On 7455 kHz is an FSK signal, 850 Hz shift, 50 Bd rate, and encrypted. It is possibly USN, out of Cutler, ME, they have used that freq for years.

T!