What did I pick up?

[dragon48]

I picked up what first sounded like morse code on 421.0 k, A.M. but I'm not sure if there were any identifiable patterns to the beeping. The problem is that the beeping stopped as soon as I started recording, but after around a minute of static, I picked up this fog horn like sound which quickly went away. Can somebody identify this sound? Also, what is being transmitted on that very low frequency?

Thanks


https://soundcloud.com/user-437184959/4210-k

 

[ridgescan]

The foghorn thing sounds like local RFI to me. The beeping could've been either a NDB out of Texas, or you or a neighbor running an air purifier. since you like to do LW here's a cool place to ID stuff
http://www.classaxe.com/dx/ndb/rna/signal_list

 

[dragon48]

The foghorn thing sounds like local RFI to me. The beeping could've been either a NDB out of Texas, or you or a neighbor running an air purifier. since you like to do LW here's a cool place to ID stuff
RNA > signals

Thanks for the reply and Link.

Does RFI stand for Radio Frequency Interference?

Also, what does LW stand for?

 

[jwt873]

Not sure what the foghorn sound was.. But as ridgescan points out, there are non directional navigation beacons down around 421 khz.. They're used for aircraft navigation. They continuously broadcast their call signs in very slow Morse code. Here's a list: LW Radio Beacons

 

[dragon48]

Not sure what the foghorn sound was.. But as ridgescan points out, there are non directional navigation beacons down around 421 khz.. They're used for aircraft navigation. They continuously broadcast their call signs in very slow Morse code. Here's a list: LW*Radio*Beacons

Thanks - I just ordered a splitter so I can listen and record at the same time.

 

[majoco]

Aero NDB's are CW stations with the ident in MCW - if you turn your BFO on you'll hear the carrier interrupted by the ident.

 

[kc4jgc]

Thanks for the reply and Link.

Does RFI stand for Radio Frequency Interference?

Also, what does LW stand for?

You have RFI correct.

LW is Longwave (freqs up to 300 khz). This includes elf (0.3-3 khz) vlf (3-30 khz) & lf (30-300 khz)

You probably already know the others but I'll go over them just for GP....
MW is mediumwave (300 khz- 3000 khz (or 3 Mhz)
SW is shortwave, otherwise known as HF is 3 Mhz-30 Mhz
VHF is 30-300 Mhz
UHF is 300 Mhz-3 Ghz
SHF (super high freq) above 3 Ghz