920.7125MHz????

[JHaislet]

I ran across what sounds like a really strong control channel in SE South Dakota on 920.7125MHz (NFM) and can't seem to figure out who's it is. I've checked the database, searching for 920.7125 in the tri-state area (SD/IA/NE) and nothing pops up.

I even tried programming a couple different types of systems (Mot/EDACS/LTR) and don't hear any traffic on any of them. Although the 396T does stay on the LTR system for 2 seconds, whereas the other 4 it just flies through (hold time is the same for all).

Any ideas?

 

[W4KRR]

I ran across what sounds like a really strong control channel in SE South Dakota on 920.7125MHz (NFM) and can't seem to figure out who's it is. I've checked the database, searching for 920.7125 in the tri-state area (SD/IA/NE) and nothing pops up.

I even tried programming a couple different types of systems (Mot/EDACS/LTR) and don't hear any traffic on any of them. Although the 396T does stay on the LTR system for 2 seconds, whereas the other 4 it just flies through (hold time is the same for all).

Any ideas?

920.7125 is not a valid frequency for a trunked system repeater output, so my guess would be an image of some sort.

If you program that frequency into the '396, does it display a system ID at the top of the display? It should if it's a valid Motorola control channel.

 

[JHaislet]

Nope, no system ID when I hold on that channel. BTW, thanks for jogging my memory about that feature on the Moto's; I had forgot all about it!

 

[W4KRR]

Nope, no system ID when I hold on that channel. BTW, thanks for jogging my memory about that feature on the Moto's; I had forgot all about it!

It may sound like a trunked system control channel, but may be something else, especially if this is the actual frequency it's on and not an image.

 

[mciupa]

Pure speculation , but.. could it possibly have something to do with weather monitoring ?

Maybe it is spitting out data to a weather station ? Make sense for your locale ?

 

[datainmotion]

From http://www.jneuhaus.com/fccindex/806_mhz.html

902 - 928 MHz

• United States Navy radars and other government operations - primary
• Industrial, Scientific and Medical [Part 18]
• Location and Monitoring Service ("LMS"). [Part 90 Subpart M] A: 902.000 - A: 904.000 Non-Multilateration
  B: 904.000 - 909.750 Multilateration
  C: 909.750 - 919.750 Non-Multilateration
  D: 919.750 - 921.750 Multilateration and Non-Multilateration
  E: 921.750 - 927.250 Multilateration
  F: 927.250 - 927.500 Narrow band associated with sub-band E
  G: 927.500 - 927.750 Narrow band associated with sub-band D
  H: 927.750 - 928.000 Narrow band associated with sub-band B

• Multilateration systems - use spread-spectrum technology to locate vehicles (and other moving objects) with great accuracy throughout a wide geographic area.
  • FCC Auction Fact Sheet
• Non-multilateration systems - typically use narrowband technology to transmit data to and from vehicles passing through a particular location.
• Automatic Vehicle Monitoring Service ("AVM") - 903-912 and 918-927 MHz [90.363]

Amateur (33 centimeter band) [Part 97]

Unlicensed low power services [Part 15]

• Unlicensed field disturbance sensors [15.245]
• Unlicensed spread spectrum transmitters [15.247]
• Intentional radiators, 50 millivolts/meter at 3 meters [15.249]
• Ricochet wireless data network

 

[JHaislet]

I did some searching for 920-921 within a 200 mile radius of here on the FCC side and while I didn't find an exact match, there were some licenses for Land Monitoring Systems as well as two of the regional electrical providers. I'm guessing it's some sort of telemetry/substation monitoring channel.

 

[Astrak]

POCSAG/FLEX. Just spitting ideas out there.

 

[datainmotion]

POCSAG/FLEX. Just spitting ideas out there.

Gesundheidt!

 

[elephant]

I ran across what sounds like a really strong control channel in SE South Dakota on 920.7125MHz (NFM) and can't seem to figure out who's it is. I've checked the database, searching for 920.7125 in the tri-state area (SD/IA/NE) and nothing pops up.

I even tried programming a couple different types of systems (Mot/EDACS/LTR) and don't hear any traffic on any of them. Although the 396T does stay on the LTR system for 2 seconds, whereas the other 4 it just flies through (hold time is the same for all).

Any ideas?

This may be a cordless phone. They operate in that band. I did some testing on my old cordless, and every time it rang, the scanner would stop and pick up what sounds like a trunking control channel. It was the base sending a ring tone to the handset. Once the handset was picked up, the sound would stop. Of course, then I could hear the conversation. YIKES! Right away went out and bought a 2.4Ghz, spread spectrum phone.

 

[JHaislet]

I doubt this is a cordless phone ringer as the tone is on 24/7/365 from what I can tell. It doesn't seem intermittent.

 

[Luis_C]

In almost every place of my city, in Hermosillo, Sonora, Mexico. In the 931.43125MHz, I hear some weird sounds too, I have always thought, it might be a cordless phone, but when I noticed that isn't only in my home, I discarted that theory. Normally is the same sound, but sometimes there's another sound, stops, and then starts again not with any special particular order.

I attached a recording. (It is a MP3 file, but ZIP compressed, because the forum won't let me to attach it.

 

[kb2vxa]

Hi all,

POCSAG/FLEX. Just spitting ideas out there.

Gesundheidt!

That doesn't help the schmutz on my monitor! Now get your naughty little butt down here and clean it up before your father gets home!

Like "Datawhazisface" pointed out in unusual detail 900MHz is a garbage band, a can of mixed nuts where just about anything can show up. I once heard the Mysterons' control signals operating Mechagodzilla battling our dear friend from Tokyo. BTW, thier saucer to saucer comms were on CB but when they heard all that nonsense they decided Earth wasn't worth the effort and went home. Hey, who wants a planet inhabited by CBers and a 400 foot lizard?

 

[321cm]

In almost every place of my city, in Hermosillo, Sonora, Mexico. In the 931.43125MHz, I hear some weird sounds too, I have always thought, it might be a cordless phone, but when I noticed that isn't only in my home, I discarted that theory. Normally is the same sound, but sometimes there's another sound, stops, and then starts again not with any special particular order.

I attached a recording. (It is a MP3 file, but ZIP compressed, because the forum won't let me to attach it.

Definitely POCSAG/FLEX aka pagers. You can decode them with a discriminator tap and a sound card quite easily. (With the right software of of course)

 

[tspainiv]

Definitely POCSAG/FLEX aka pagers. You can decode them with a discriminator tap and a sound card quite easily. (With the right software of of course)

I too was curious about these sounds. Now I know what the POCSAG/FLEX tones sound like, but what about this one???

 

[321cm]

I too was curious about these sounds. Now I know what the POCSAG/FLEX tones sound like, but what about this one???

Some sort of telemetry for a utility maybe...

You might find this interesting, it's a "sound dictionary" http://www.kb9ukd.com/digital/

 

[tspainiv]

Some sort of telemetry for a utility maybe...

You might find this interesting, it's a "sound dictionary" http://www.kb9ukd.com/digital/

I had found that long ago....I didn't even thing of looking at it again!! Thanks for bringing it up. I had used it once to figure out the type of sound I heard comming from one of our local PDs after they would key up on their radios.

 

[Luis_C]

Definitely POCSAG/FLEX aka pagers. You can decode them with a discriminator tap and a sound card quite easily. (With the right software of of course)

I see, really thanks for the answer.

Also, really thanks about the "sound dictionary".

Greets,

Luis

 

[nexus]

everyone should bookmark that digital sound directory. it's a great asset.

 

[datainmotion]

Hi all,

POCSAG/FLEX. Just spitting ideas out there.

Gesundheidt!

That doesn't help the schmutz on my monitor! Now get your naughty little butt down here and clean it up before your father gets home!

Like "Datawhazisface" pointed out in unusual detail 900MHz is a garbage band, a can of mixed nuts where just about anything can show up. I once heard the Mysterons' control signals operating Mechagodzilla battling our dear friend from Tokyo. BTW, thier saucer to saucer comms were on CB but when they heard all that nonsense they decided Earth wasn't worth the effort and went home. Hey, who wants a planet inhabited by CBers and a 400 foot lizard?

You're drinking again aren't you?:lol:

Sincerely,
Datawhazisface