Digital Comms on ISPERN / Priority ONE

[W9WSS]

At approximately 2:45 pm Central time, Tuesday, April 15, 2025, I heard what I believe was digital comms on ISPERN 155.475 MHz / Priority One SC21 Talk Group 9051. It sounded like straight "white noise," with no breaks, other tones, or sounds. I couldn't tell if it was one or two units, as the "hash" noise was constant for about 30 seconds.

I didn't hear any other "normal" FM comms or transmissions. I also listened to this earlier in the day; I don't remember when, as I was busy and didn't drill down or watch the displays on my scanners.

Will Sperling W9WSS
Co-Director & Moderator
Email: carma+owner@groups.io

 

[Premises2972]

At approximately 2:45 pm Central time, Tuesday, April 15, 2025, I heard what I believe was digital comms on ISPERN 155.475 MHz / Priority One SC21 Talk Group 9051. It sounded like straight "white noise," with no breaks, other tones, or sounds. I couldn't tell if it was one or two units, as the "hash" noise was constant for about 30 seconds.

I didn't hear any other "normal" FM comms or transmissions. I also listened to this earlier in the day; I don't remember when, as I was busy and didn't drill down or watch the displays on my scanners.

Will Sperling W9WSS
Co-Director & Moderator
Email: carma+owner@groups.io

Did you get a NAC? Is it possible this was just interference that sounded like white noise?

 

[W9WSS]

Did you get a NAC? Is it possible this was just interference that sounded like white noise?

I'm using an SDS200; No NAC display is available.

 

[werinshades]

The noise you were hearing was an open key on the VHF patch on ISPERN from an unknown unit. It was on and off all day today as if the microphone wasn't properly seated in the holder or something. Kind of a pain for everyone to listen to I'm sure.

 

[W9WSS]

The noise you were hearing was an open key on the VHF patch on ISPERN from an unknown unit. It was on and off all day today as if the microphone wasn't properly seated in the holder or something. Kind of a pain for everyone to listen to I'm sure.

When do open keys have digital comms for carrier? If it was an open key unless the specific VHF radio was programmed on ISPERN for digital, why couldn't I hear any background noise or other ambient clues?

 

[werinshades]

When do open keys have digital comms for carrier? If it was an open key unless the specific VHF radio was programmed on ISPERN for digital, why couldn't I hear any background noise or other ambient clues?

It's a VHF patch to ISPERN. Many departments are set up this way. The audio quality isn't very good, no radio ID being transmitted either. I heard it all day today too.

 

[RoninJoliet]

l also heard it but I didn't hear any digital associated with it just like a muffled key up every so often ?

 

[werinshades]

l also heard it but I didn't hear any digital associated with it just like a muffled key up every so often ?

Yes, that was it.