Strong RTTY or similar on 22m

[Ed H]

Hi Folks,

Lately, I've been noticing strong RTTY (or similar FSK mode) signals within the ISM 22m band - at least two sources were apparent last weekend (11/12 March 23). Please add your observations to this thread.

Thanks

Ed

[Josh]

If you can record some audio we can try to decode it.

[Null Detector]

I have heard a RTTY like data signal sporadically over the past week centered around 13558 kHz using the KFS SDRs or direct using my receiver and a Universal M-7000. Both methods indicate the shift as 200 but not sure if baud rate is 75 or maybe 100. I tried the SDR FSK extension without any luck. (probably need a tutorial) When strong enough to hear direct the M-7000 yielded the best result in that I am seeing nonsensical data. Either I haven't figured the mode out or it is encrypted.

[N9QIW]

I am picking that same digital signal very well 5-7+ here in NW Indiana (Chicagoland).   I also heard a 2-3 hifer CW beacons on the air before I put QIW on the air a few minutes ago until local dark or I use the IC-7300 for ham work.

[Josh]

A kind soul sent me a 22m ism recording where a CIS 36-50 signal is interfering with a delicate ocean surveillance radar. So there's one source of fsk on ism bands.

[Ed H]

Thanks folks.

Yes, the KFS SDR is a reliable way to hear these signals. I'm further South but have also heard them while monitoring HiFERs. I can certainly record some audio, and also have a go at decoding.

Ed

[Treehouse SWL]

I just checked the signal on 13558 via the KPH SDR and then compared it to the strong signal I'm hearing here north of Seattle on the same frequency; they seem to match.

[DCtoLight]

I heard it pretty weekly in Michigan at about 2000z 10 Apr 2023. Using MMTTY it is definitely 200 Hz shift. Tried normal then reverse at 45 baud but then it went QRT.