Batboard

I would like to know what this "Chirping" noise is that is at the start of the transmissions on some radio systems.

If I hear it, it's typically on VHF police radio systems.

It's a chirping noise, and sometimes I hear it only on the dispatch side, sometimes I hear it only on the car side, sometimes I hear it on both sides and sometimes never hear it at all, or a combination of all these.

So it's obivously not some setting on the radios, so what the heck is it and can you identify what equipment they are using by hearing the chirp?

Here is a WAV file, just click on the link and it will play through your computers speakers. It's 380kb, so I totally understand if you don't want to do it.
The actual speech is unintelligible, but you will still hear the chirping I am talking about. It's in this 16 second recording about 3 or 4 times. Remember, the very first thing you hear in the transmission.
HERE'S THE NOISE
http://wwnoise.wav

Sounds like the same thing the PD here in Jackson uses. I think it has something to do with the console system they use... someone else may be able to give a little more insight.

BTW, we're up in the 500 MHz range.

Sounds like the tones from a Spectra tac.

Mike

We have a similar chirp on our ema's base for 155.220 simplex and 46.14 fire. You can only hear it on coded squelch (usually on the scanner). If your radio is set to pl squelch you don't hear it. I'll have to ask the ema director because I don't have a clue what it is.

Sure it's only been 25 minutes since I posted that but it looks like I got youse guys stumped!

First, I am listening in on carrier squelch. And I believe you may be correct in saying that with the TPL/DPL, they can't hear it because most of the transmissions... These people don't wait, they just start talking immediately and the first second of speech is not there, although I suspect they must hear the speech or pratice waiting a second before talking, like the rest of the repeater-using world.

I was watching this movie "Lucky Numbers". John Travolta is in it. If you've seen it, towards the end of the movie, just after John T. flips over an 18 wheeler, the cop gets dispatched. When the dispatcher talks, you hear that very same noise. AND when the cop resonds to the call, you hear it on his transmission too. Of course, I realize this is a movie and that must be some sound effect, but still... It was then that I realized I had to find out what that noise is, because I've been wondering for a long time.

Why don't I think it's a console? Because from time to time, I hear this noise on commercial systems, you know construction companies and things like that. Whatever the case is though, I don't hear it as often as I used to which makes me think it's something OLD.

Only thing that I can think of is that the tone remote tones are getting in. If I key up the console while someone is talking or if the repeater is still xmitting, you will hear them at the console, but that's it. I'll try to make a recording tonight. Lots of hum in there so I counldn't really hear it.

Lawrence Kansas had the same thing really bad on their old VHF system. It was twice as loud and as long as this. I think he's onto it maybe when talking about tone remotes. They were running some very old equipment. It sounded like some sort of filter/reed/part etc.... being pranged then quickly settling down making a binging noise.

They run a smartzone 800 system now. There are two 800 conventional towers patched into the main dispatch talkgroup on each side of the county to extend range. I notice that when someone keys these repeaters you actually hear the dit, dit, dit like from a trunking radio or almost like a nextel. It's almost like the audio lines are just patched into the mic of a trunking unit and are not going straight to the controller or base somehow. (I suppose they likely are).

I have one for you guys. It's on 154.480 here. It sounds like two units (machines) talking back and forth. It's a flute sound. Back and forth they go for years non stop seemingly at random intervals. One signal is always lower than the other. It sounds like two tones but they are kind of soft and are obviously data since the pattern changes. Well hell, for the first time I've heard voice on it now... I can't really tell yet who they are. They are talking about KCMO and Independence, something about big wigs from the state coming to look at some equipment. Maybe it's power company data or something.

???


mancow

pj wrote:Only thing that I can think of is that the tone remote tones are getting in.

I agree, if the dispatcher here keys while the base is still active, you hear the same exact noise.

You have so much hum on the audio recording, it makes it hard to hear the tones your talking about. Any chance of doing it again and try to reduce the hum level.

If you can hear it with a carrier squelch radio, do you also hear it with the squelch open and the base not transmitting?

I may have missed it in the posting, but what is the frequency your listening to? By any chance is it VHF around the 155.7 to 156 range? The first thing that comes to mind is cable TV leakage or off the air intermod from a local TV station. Need to hear more of the audio without the hum.

Jim

I'm going to go with Tone remote noises.

I know, that last recording was awful.
I tried to get that hum out, just can't. I think it has something to do with the mono-to-stereo because my line in cord is mono.

OK, this new recording is BETTER. The hum is not quite as loud.

AND, the very last thing you hear in the recording is the chirp.
It's a little smaller, 232kb I think, real short.

The frequency is actually 153- something. Don't want to reveal the name of the department because I don't want any radio salesmen calling them to get them to switch to trunked. I like to know where the bears are!

htradio.wav
Go to^ to hear it.

Oh I forgot, I do not have the PL tones, therefore I cannot listen with that. I was thinking of getting the Icom IC-R5 scanner which has a PL/DPL tone scan, but that would be the only reason, because I found it hard to use with no keypad.

Any other way to do a tone scan from afar?

Definately sounds like a short little blip of tone-remote noise is sneaking in.

Page not found is what I find??

That is tone-remote tone leaking through. CoolEdit says the tone is 2807.4 Hz.

As for the PL.. you will need to patch this into the sound card's "line in" rather then using a microphone.

The only PL tone I could decode was 120 Hz... the second harmonic of 60 Hz.

sounds like tone from the spectra tac. i jear it hear on rockland but you only here it on a scanner because the scanner doesnt have the filtering to take it out. you can here the full set of tones if you key the repeater just as it is going down.

A 'tone remote' tone is two tones. First is a queing tone, second tells the remote which channel to use. The common one is 2200 hz and 1950ish Hz to open up channel #1. I have a WAV file of it but nowhere to store it for y'all to hear.

What you are hearing may be from a Spectra TAC. I've never heard that tone before. But it doesn't sound like a 'tone remote'.

Guard tone is typically 2175, function tone is 1950. Most satellite receiver comparators(voters) use 2175 as well, so it could be either. This PC has no speakers so I cant listen to the wav file.

Another thing to point out - it could be the microphone on the console activitating just before the clear to talk tone is sent. Maybe your catching the end of that. I know one of the dispatch consoles here tends to do that.

-Alex

My county 911 (fire/ems side) is all on lowband, and a similar 'phenomenon' occurs whenever fire control keys up to talk - what sounds like a very short 2 tone chirp at the beginning. I've always wondered what it was - I figured it was their console. So can these quick tone chirps are used for "remote tone?"

[quote="GeorgeJEfferson"]Sure it's only been 25 minutes since I posted that but it looks like I got youse guys stumped!

Stumping this bunch ? Not likely with the talent pool here.

RadioSouth wrote:

GeorgeJEfferson wrote:Sure it's only been 25 minutes since I posted that but it looks like I got youse guys stumped!

Stumping this bunch ? Not likely with the talent pool here.

The Wayne County Sheriff (MI) 800Mhz type II trunked system has 2 repeaters that make a "bee boop" noise. One when anyone keys up, the other only when a dispatcher at a console keys the mic. None of the other repeaters make the noise.

-Josh

Its the tone remote keying and unkeying
You should hear the tone on the recorder at the dispatch site
Nice whine in the background when they are talking
Were now on 800 trunking with digital recorders. No more tone remotes, no whine.

Fowler

One of our tower sites do the same thing... Everytime you key it up you get what sounds like a "pleek" then a very low level whine. So I'll cast my vote for the tone remote leaking a little bit of the key tone.

On the MX Medic channel, the south transmitter is horrible. Either the filter is shot or the tone is out of alignment or something. As long as the dispatch mic is keyed, you hear the high pitch tone in the background.

Who cares about a slight bit of tone. What the heck is all that horrible hum about?!

Ok, so this tone remote things makes sense to me. However, not to sound like an idiot, but can anyone explain this to me? I'm not sure I completely understand what the tone remote is for. I'm used to using radio systems that when you key and talk, you hear the talk on a receiver

Is this tone remote thing because the console in question sends radio traffic out over another frequency (ie microwave uplink), and the tone remote opens and mutes the output from the tower? Thanks in advance!

~a curious individual

If anyone wants to hear the tones a tone remote will make on key-up, listen to http://personal.cmich.edu/~weirm1js/batlabs/beep.wav . That was taken from the local PD repeater, when the dispatacher keyed up before the repeater dropped.

To find out more about tone remote frequencies and what not, check out http://216.239.57.100/search?q=cache:VO ... cies&hl=en

x1sspic wrote:I'm used to using radio systems that when you key and talk, you hear the talk on a receiver

~a curious individual

It is usually transparent. You may never know it is there. The only time you would here them normally is on a parallel remote base (You'd hear the first two, a quick beep beep), or if you key up a base during the repeater trail. You can also hear the same soft beep-beep on the headset which is currently on my head when I key up.

Jonathan... My understanding is that's not the normal tone remote thingy. That's simply a warning tone to tell people that the console is taking over while another unit is transmitting. I believe that's a centracom 2 option. I could be wrong, but that's how it was explained to me years ago.

Pj wrote:Jonathan... My understanding is that's not the normal tone remote thingy. That's simply a warning tone to tell people that the console is taking over while another unit is transmitting. I believe that's a centracom 2 option. I could be wrong, but that's how it was explained to me years ago.

Nope. What Jonathan has linked is a tone remote. Put the frequencies into Cool Edit and make one of your own and see.

Pj wrote:Jonathan... My understanding is that's not the normal tone remote thingy. That's simply a warning tone to tell people that the console is taking over while another unit is transmitting. I believe that's a centracom 2 option. I could be wrong, but that's how it was explained to me years ago.

Not that it's all that important in the grand scheme of things... but I beg to differ.

I checked the recording link I gave in CoolEdit, and discovered that it is 120 ms of 2175 Hz, followed by 40 ms of 1950 Hz. In other words, that would be the typical tone-remote command to keyup on F1.

The only thing that boggles my mind is why the guard tone was 6 db LOWER in level then the F1 select tone. Typically, the guard tone is higher in level then the option function tone.

Check out http://www.vega-signaling.com/Applicati ... uide01.htm .

Sounds good to me. I'll try to make some more recordings tonight, as long as I remember to take the disk with me this time. The tone that you put up was the one that I was going to tape, however I failed to state that the tone I was talking about ealier is a different two tone. Springfield PD uses it and they run with Centracom Elite/MSF5000 and Quantar repeaters. Its a different set of tones that yours. Its also not the "Alert 2" tone. I'll see what I can grab tonight.

Oh for pete's sake, are you guys making mountains outta anthills?

Do you hear "DEE-DUL" then it's gone? It's a freakin tone remote. If you don't hear "DUL" then it's missing the 1950 thus a comparator(voter) system. (DEE) just 2175. DEE 2175 is guard tone.

Same :o you hear on "Cops" intro? "529 I have him at gunpoint" DEEDUL! 529 10-4......

Ok, it's a Centracom 1, or 2 or T1600, or CPI DR10, or...

I agree fully with tone remote tones. I ran the tone through a freq analyzer, and I get close to 2178 , and then 1953.

KH wrote: Same you hear on "Cops" intro? "529 I have him at gunpoint" DEEDUL! 529 10-4......

You forgot : "529 10-4 covers code 3" at the end.


Signed: Cops Freak..

KH wrote:
Same you hear on "Cops" intro? "529 I have him at gunpoint" DEEDUL! 529 10-4......

DUH! Yes, he's right. That's the one.

B

Is it MDC you are possibly hearing? I dont speak kasquaaaakian language so I cant tell you. Here a sound of my MDC PTT ID on my F.D radio.

<a href="http://www.realty-radio.com/14 - Data Burst.wav"> Nick's MDC Burst </a>

motorolamonster911 wrote:I agree fully with tone remote tones. I ran the tone through a freq analyzer, and I get close to 2178 , and then 1953.

KH wrote: Same you hear on "Cops" intro? "529 I have him at gunpoint" DEEDUL! 529 10-4......

You forgot : "529 10-4 covers code 3" at the end.


Signed: Cops Freak..

DAMMIT I GOT THE DEEDUL PART IN THERE SO HUSH!!!

hehehe

I thought LAPD's 'sound' went BEEEDAHLAHBOOP???

Am I missing something here?

Scott

Ok, if nobody else will I'll say it...
the LAPD thing is


MODAT


that's it, nothing more


mancow

I was just making a joke about the MODAT thing...
I was trying to get the correct sound for the spelling for it...lol

But they are right in saying that the tone remote sound can be heard on the intro to COPs.

Scott

I know.... so was I


mancow

hehehe...

Is MODAT suposed to sound like this?

I just made a fake cap-code (1234567) and it gave me this:
http://www.realty-radio.com/modat.wav

No, that is not MODAT. MODAT sounds like BEEEDAHLAHBOOP...
It's like 5 short bursts of sound...

There are some sound wavs of MODAT around here somewhere, but I can't remember where they are...

Scott

Courtesy of kb9ukd and his web site, here is a MODAT sample...

http://www.kb9ukd.com/digital/modat.wav

Hope this helps out the confusion about MODAT

Scott

Ok, I tried using 5 tones this time. (54321)

http://www.realty-radio.com/newmodat.wav

If this isnt it, I'm gonna throw this software out the window.

Listen to the sound that Rescue161 posted just before you. That is modat. Your computer generated sound is not the correct timing but the concept is the same.



Wanna hear what a parrallel tone-remote base would sound like?

http://www.lawrenceweb.net/sign_on.wav



And by the way, it is

"132 & Bush, I've got him at gun point."
"Roger, Gun point. 132 & Bush, covers code 3"
"yadda yadda use Tac 2"[/url]

Yep, that one sound sample higher up in this thread is indeed MDC.

nmfire10, your sound sample is the identical sound I hear on the county lowband frequencies here. You sound knowledgeable, so can you explain to me how a parrallel tone-remote base works? This is one area of radio technology that apparently is new to me, and as such, I'd love to understand it