ANF Service Net P25 ?

[Progline]

I'm getting a lot of what sounds like P25 regular bursts on the ANF Service Net 171.55 channel. Is this legit, or is my scanner hearing things? I thought ANF & LPF were still conventional analog.

(could be DMR, Nexgen or whatever, I can't tell the difference in digital sounds)

 

[iscanvnc2]

171.55 is LPF Admin Net which I just heard as I type this; good/old analog. I scan both Admin & Forest nets regularly & don't recall any P25.

 

[Progline]

EDIT _ My error. Frequency should be 171.500. I don't see the option to edit my original post, I guess too late to fix it.

 

[iscanvnc2]

I'm with you now. Interesting. It appears to be some type of periodic data burst, about one second long every 30-31 seconds. Something you might expect from telemetry, but on this frequency at 3 out of 5 bars?

Anyone care to jmp in?

 

[ladn]

Image/intermod product? Ducting?

I remember many years ago when ANF was on 171.575. I (and a lot of others) were suddenly hearing image/intermod on Forest Net from other 3-letter federal agencies. This was in the pre P-25, unencrypted analog days.As I remember, the problem had to do with a new transmitter antenna for KABC-TV on Mt. Wilson.

 

[bcorbin]

I'm with you now. Interesting. It appears to be some type of periodic data burst, about one second long every 30-31 seconds. Something you might expect from telemetry, but on this frequency at 3 out of 5 bars?

Anyone care to jmp in?

It’s P25 with an NAC of $293. They had something similar running on one of their primaries a year or two ago (much less frequent pinging).

 

[iscanvnc2]

For what purpose???

 

[bcorbin]

For what purpose???

No idea 8*) The transmissions are about 2 seconds in length and activate the audio output (though I haven't heard any audio). My suspicion is there may be something to look at in the data stream, but I haven't set anything up to do that.

While I'm here, I should correct myself - last time I heard something like this, it was on an LPF primary, not an ANF primary.