Scanner for 6.25KHz analog FM?

[KG4GUF]

Are there any scanners, or radios, that can receive 6.25KHz analog FM? I'm listening to railroad frequencies (usually around the Atlanta, GA, USA area) for both CSX and Norfolk Southern. I have a Yaesu FT-8800 in my car, and an Icom IC-v8000 at my house. However, the narrowest bandwidth they can be set to is 12.5KHz (narrowband). The transmissions from the locomotives are pretty quiet and hard to understand at times. I finally hooked my SDR up and observed the signals on the waterfall display. It looks like the railroads have gone to 6.25KHz bandwidth (see attached screenshot), but staying on analog voice, they haven't gone to NXDN yet. Are there any radios out there that can handle this narrower bandwidth for FM audio? Thank you!

 

[mmckenna]

There is no industry standard for 6.25KHz FM analog.

Likely it's a poorly aligned transmitter, damaged microphone, someone holding the mic too far away, etc.
Not familiar with that SDR, might be an issue with that, though.

 

[chief21]

It looks like the railroads have gone to 6.25KHz bandwidth (see attached screenshot), but staying on analog voice, they haven't gone to NXDN yet.

The standard US band plan for railroads is 12.5 kHz (FMN), so it's not likely that you're hearing 6.25 kHz analog signals. As I understand it, 6.25 bandwidth signals need to be digital. Perhaps the audio is low because the operators you're hearing are not using good radio technique.

 

[wa8pyr]

The standard US band plan for railroads is 12.5 kHz (FMN), so it's not likely that you're hearing 6.25 kHz analog signals. As I understand it, 6.25 bandwidth signals need to be digital. Perhaps the audio is low because the operators you're hearing are not using good radio technique.

This. Train crews have a very annoying habit of keying up the radio and talking into the mic from arms‘ length, instead of picking up the mic or handset and speaking into it normally. Sheer laziness, basically.

I’ve seen it happen so many times I lost count long ago.

 

[OpSec]

The only 6.25kHz traffic would be NXDN, but if you're hearing it analog then it's still 12.5kHz.

Frequency modulation (FM) means the width of the (visible, in your case) signal varies based on the amplitude (strength) of the modulation...a soft talker will have a narrower signal (less modulation) than someone shouting into the mic (more modulation). Watch your SDR on various signals and you'll see the width of the modulated signal change.

You're hearing a bad radio, soft talker, or both.

 

[ratboy]

The crews around here in NW are infamous for yelling the loco number and just jabbering something, or the train symbol and jabbering. The NS crews I listen to most of the time these days are a little bit better than the old Conrail crews were back 25 years ago, but part of that is just simply the cabs are quieter now. I had a huge stack train pass me last night, and I have no idea what the conductor said to the dispatcher and I was literally 50 feet from the train as he was talking. It had a DPU in it with a weird looking headlight setup and I haven't been able to figure out what it was.