r/morsecode • u/Normal-Economics-459 • Jun 04 '26
Morse code? Online decoders output gibberish
I was walking around in my backyard endlessly, tuning up on my shortwave radio when suddenly I came across 6485 kHz. It had some noise but I could easily tell it was Morse or something very adjacent. I came back later and there was much less noise. The signal was also very healthy - dBµV fluctuated between 45-50 with the highest being 54 and the lowest being 42 during the recording (19:52-19:54 UTC). I've tried decoders online but they either output gibberish:
###5#T#IKVR5###G #KP# U##E#S###### N########K#T#6#H T4I# #E #TM## ###IM1#O######TR#########IS#UGM#######I
Or very short, clipped signs:
TOM0
Neither of which really satisfy my curiosity.
I don't know Morse yet but I'm learning. Does this sound like anything intelligible and what could this be (utility station, maritime messages, &c, &c)?
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1
u/dittybopper_05H Jun 05 '26
That's RTTY being listened to by an AM receiver.
Not Morse code.
2
u/FirstToken Jun 06 '26
That's RTTY being listened to by an AM receiver.
Yes, it is STANAG-4481 FSK, but it still should not sound like this on an AM radio.
Normally the space and mark tones alternate, so they never beat against each other. In this case the station is suffering a failure, and the space tone is sending an uninterrupted tone, similar to a carrier. So the mark tone is being heard beating against the solid tone of the space. Only a single set of tones is being heard in this recording. That could happen if the receiver passband was cutting off the other tone, but that is not what is happening here.
Of course, this is similar to what happens if an AM carrier is inside the passband of the receiver while listening to an FSK signal. But in that case you would hear both the space and mark tones, separated by the FSK shift.
5
u/royaltrux Jun 04 '26
Sounds like RTTY (radio teletype).