Digital signal motor boats when out of range (Ripon, CA)

[gusbuster1217]

A question out of curiosity and for some sanity.

This only happens with this one station\frequency for the PD of Ripon CA.

As I go out of range, instead of hearing a blank sound like I do for the city of Manteca and Tracy I get this annoying motor boat sound. Gets to the point where I have to either stop scanning that bank or do a L\O. I always forget to take the L\O off when I'm local, so do miss some of the action.

What is that motorboat sound I'm hearing? Is it a digital signal that the computers in their cars are sending and the 396 is trying to decode it?

Unless the signal is ENCRYPTED (so far, I've only heard the city of Manteca use this) their p-25 (nac) signal does get decoded properly and sounds pretty good. When it scans on this channel, I’m just looking for a possible setting that I can try and get rid of this annoying sound when out of range.

Thanks
John

 

[Lithium99]

I think I've come across the exact same issue! It happens around Tracy area, near the base of the Alatamont pass, right?

If it's the same sound my 396t is picking up, the best I can describe it is more of a harsh hammering sound that lasts only for a couple seconds at a time. It doesn't sound quite like the p25 digital sound as heard on an analog scanner to me. For sure, the 396t doesn't seem to decode the signal at all. I've just chalked it up to another agency in the area using the same frequency for data (MDT's possibly).

 

[gusbuster1217]

I think I've come across the exact same issue! It happens around Tracy area, near the base of the Alatamont pass, right?

If it's the same sound my 396t is picking up, the best I can describe it is more of a harsh hammering sound that lasts only for a couple seconds at a time. It doesn't sound quite like the p25 digital sound as heard on an analog scanner to me. For sure, the 396t doesn't seem to decode the signal at all. I've just chalked it up to another agency in the area using the same frequency for data (MDT's possibly).

Bingo, I forgot the name of the road (it's a bypass that I take to avoid traffic delays around the 580, 5 and 205 interchange, maybe Grant Line). It also happened to me quite a bit on hwy 88 as I got close to Lockford.
I didn't remember what the computers in the patrol cars were called. One thing that I did notice, anytime I heard (sounded like Morse code) the mtd signal; it would immediately make that awful sound.

But why only with the Ripon frequencies?

I know sometimes with some agencies, what they use for central control irrigation systems, I thought they broadcasted in the lower bands,via satilite link or were land line based.

 

[SCPD]

Bingo, I forgot the name of the road (it's a bypass that I take to avoid traffic delays around the 580, 5 and 205 interchange, maybe Grant Line). It also happened to me quite a bit on hwy 88 as I got close to Lockford.
I didn't remember what the computers in the patrol cars were called. One thing that I did notice, anytime I heard (sounded like Morse code) the mtd signal; it would immediately make that awful sound.

But why only with the Ripon frequencies?

I know sometimes with some agencies, what they use for central control irrigation systems, I thought they broadcasted in the lower bands,via satilite link or were land line based.

Before I can say for certain, which frequency is this? If its the frequency I think it is it's most likely AVL

 

[gusbuster1217]

Before I can say for certain, which frequency is this? If its the frequency I think it is it's most likely AVL

0460.0500 Dispatch Ripon

AVL? What is this\that?