Beeps/tones on trunk repeaters?

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Jay911
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Beeps/tones on trunk repeaters?

Post by Jay911 »

Hi there,

The Smartzone system that I use has recently developed a beep that occurs before & after some of the transmissions, and is audible on the radios and the consoles, and on my scanner as well.

The tone seems to go on for all the time the repeater is keyed up, except when voice traffic is present. So for example you'll hear "(tone) 21 Pump to Dispatch (tone)".

The tone before the transmission is not the remnants of the talk permit tones, which we also occasionally hear (the last half of the last beep, generally). It's a separate solid tone.

We were able to look at Zonewatch today and confirm that it is coming from one specific repeater on a site. We (the dispatchers and the techs) keyed mics until that repeater was next up in rotation, and every time, it would generate the beep when it was used.

The techs and bosses are looking at it themselves (all they've seemed to do so far is make it happen on almost all the repeaters). I am kind of interested in learning what this might be, even if not for purposes of solving the problem, but because I'm the inquisitive type.

One of the techs mused to the other that it might be a tone that comes onto the repeater by default after the site enters Site Trunking (which happened several times over the past week with all our sites, during 'upgrades'). The other tech didn't really seem sure one way or the other on that point.

The tone sounds to me like it lasts as long as carrier squelch is open. On the Centracom consoles, you can hear the end code cut off the sound almost to nil, but it still can be heard for another half-second or so while carrier is still open. On the portables and scanners ignoring the end code, it lasts until CSQ closes. And to me, it sounds exactly 1000 hz.

I'm going to try to get a sample from my scanner tonight. If I get successful, I'll post it here. In the meantime, has anyone had this occur before, and/or know what it is?

Thanks in advance...
PETNRDX
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Post by PETNRDX »

This is a long shot, but is there any chance its the "I'm running on battery" warning tone?
Will
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Post by Will »

The Battery Revert Tone is NOT (usally) a steady tone, it is a short tone every 30 to 60 seconds. BUT... It could be maybe?? programmed that way in the repeater or trunking controller.

The tip, that I read, is that the tone is steady, same frequency and is on the carrier for the entire TX, even when the low frequency connect tone is dropped. One place to look would be the repeater's mic audio and trunking controller TX audio inputs.

Someone left the "test tone" on!!!!
RKG
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Post by RKG »

As near as I can tell, there is as much black magic in the SmartZone controller as there is in some witch doctor religions, and I do not purport to understand it all. That said, and strictly as a guess, I'd bet this is a tone that signifies that the controller has detected some real, perceived or incipient failure of the backhaul data paths that could (but obviously hasn't yet) throw the system into either site trunking or failsoft. I'm surprised (well, maybe that's an overstatement) that it can't be found from the diagnostic messages.
ASTROMODAT
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Post by ASTROMODAT »

The DC revert tone on the Quantar is a momentary beep that is broadcast every few seconds with each transmission until AC primary power is restored. Sounds to me like the Quant that is spitting out the tone beeps is on DC back-up power.

larry
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Jay911
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Post by Jay911 »

I don't think it's a battery revert tone. It is still going on now, after 30+ hours (at least, that I'm aware of - surely longer). I've heard the battery tone on my VFD's conventional repeater, and if it's the same type of tone for both types of repeaters, that's not it.

One thing that was tossed into the air today was that this seems to be happening on the repeater that was "first" worked on when the "upgrades" were done earlier this week. So I'm thinking that RKG's appraisal is pretty close.

The techs believe they are going to have to go to each of the 6 sites (!) and check every repeater to make sure they're all reset properly.

Here's a sample I pulled off my BC250D scanner at home recorded today. Sorry for the scratchiness, my location is literally on the fringes, as my avatar message says. :)

Thanks for your input, everyone!
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Bob
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Post by Bob »

My ears aren't THAT good, but that tone does sound like it's in the ballpark of 1000Hz.

I'd check to make sure that someone didn't leave a 1k test tone on after service. That'd be the simplest thing to check. After that, I'd try to chase down RKG's theory.
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Jay911
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Post by Jay911 »

Well, I used a sound program to generate a 1000 hz tone and play it side by side for comparison. :)

One would hope that a test tone generator would be easy to find, but with the kind of results seen from the techs and Motorola (who seemed to have no idea or details on our setup, even having been given the sysid and city), I'm not sure at all. :oops:
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HumHead
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Post by HumHead »

Yup. That's 1K.
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wx4cbh
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Post by wx4cbh »

Similar problem in a nearby city with Type II system was revealed to be a 1K test tone from a station test set on one of the receivers was left on. It only appeared when that particular receiver was voted. Just a thought.
Alan
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Post by Alan »

If you narrowed down to one repeater at one site, then the first thing that I would do is reset the repeater. First download the error log from the Quantar (I assume Quantar). Then do a power down/power up.
I have had tones before and a reset fixed things up.
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Jay911
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Post by Jay911 »

Alan wrote:If you narrowed down to one repeater at one site, then the first thing that I would do is reset the repeater. First download the error log from the Quantar (I assume Quantar). Then do a power down/power up.
I have had tones before and a reset fixed things up.
Well, like I said, my input would probably not be requested.. I'm kind of doing this for my own edification.

The result on Friday night seems to be that almost every repeater (yes, Quantars, from what the techs were mumbling at one point) is generating the tone. It's driving the users nuts, asking us if there's a problem with their radios.

Friday evening it seems like someone has shortened the time for the turn off code so that the tone, while still there, is not heard for anywhere near as long. I can definitely still hear it on my scanner, but it's a fraction of a second instead of a full one.

Feels like they put a band-aid on an amputation. :roll:
Will
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Post by Will »

Jay911 wrote:<snip>
with the kind of results seen from the techs and Motorola (who seemed to have no idea or details on our setup, even having been given the sysid and city), I'm not sure at all. :oops:

This IS what gives us 'Real Motorola techs' a bad name.
bernie
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Post by bernie »

My two bits worth:
I have worked on Simulcast, AMSS, as well as stand alone 6809 trunking, but never on Smart Zone.

I presume that if the system infrastructrure is at all similar to the others that the site controller, or what ever performs this function can not modulate the transmitter, except for Control Channel, so that is not where the tone is coming from.

There has to be some sort of audio link from the central (master) site controller, or switch to each transmitter.

I would look here. This of course requires a site visit. Perhaps some one left a tone generator on one of the channels.

Unfortunately, trunking seems to be a dead issue with Motorola tech support, so many of their personell are not familiar with "legacy systems".
System support may not have the system diagrams for your installation.
Aloha, Bernie
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