Quantar Service Beeps

[n9jig]

We have a pair of Quantar repeaters, one of which is sending a series of rapid beeps over the air and to the consoles on occasion. The beeps tend to last for 30 to 60 seconds and then end.

You can hear a recording of this at http://www.n9jig.com/quantar.wav

The tech checked the mains and battery voltages, they are in spec.
He also checked the RF output and reflected power and they are correct.
No relevant messages appear in the logs.
I had him disable one of the repeaters for the weekend to see if we can isolate it to a specific repeater.

Any ideas?

[Rod Farva]

Just to confirm that the quantar error log has been checked thru the serial connection on the station itself?

[n9jig]

Yes, the logs have been checked thru the RSS according to the tech.

[RKG]

I'm not where my manuals are stored, but from memory, the Quantar has up to four status message beeps that can be sent over the air and (optionally) down the wireline.

One is for loss of 110V and station on battery (with power reduction).

One is for PA not fully loading.

Can't remember what the other two are.

This is covered in, I believe, the SCM portion of the Quantar Manual.

[Bill_G]

OMG. New one on me. I've never heard a Quantar do that. I would get a fresh pair of eyes on it. That is not the beeps they make when you have an out of lock or pa fail. I would be tempted to refresh the codeplug first.

Your statement about not knowing which repeater it is has me curious. Obviously you do not have wireline control. Otherwise, you would know which site it is already. So, you must have multiple repeaters with at least a common output. Is there anything external attached to the stations that could be passing on an alarm? Could it be a user with a bad radio? Are there users with digital capable radios trying to run out of mode?

[n9jig]

OMG. New one on me. I've never heard a Quantar do that. I would get a fresh pair of eyes on it. That is not the beeps they make when you have an out of lock or pa fail. I would be tempted to refresh the codeplug first.

Your statement about not knowing which repeater it is has me curious. Obviously you do not have wireline control. Otherwise, you would know which site it is already. So, you must have multiple repeaters with at least a common output. Is there anything external attached to the stations that could be passing on an alarm? Could it be a user with a bad radio? Are there users with digital capable radios trying to run out of mode?

We have a single conference bridge with a CTI controller available at the console position. The operators report that when the beeps are heard there is no indication from any of the 10 satellite receivers, so I don't think it is one of the AstroTac's or one of the subscriber fleet. I would imagine if the beeps could be generated by one of the consoles on the conference bridge (there are 5 in total, one local and 4 connected via dual FDDC lines) but the operators would have no indication on the comparater display. Our conference bridge does not indicate which console is talking, either at the rack or console.

The comparater audio is fed thru the CTI which allows the operator to switch from the "Main" to the "Standby", but all the CTI does is swap the audio path, both repeaters stay on-line. We found this out when we programmed in CW ID a couple years back...

AFAIK there are no digital radios among any of our 5 agencies sharing the channel. It is mostly Pro Series and Jedi portables, CDM mobiles and a few Kenwoods here and there.

The only other thing that comes to mind is that we reprogrammed to Narrowband a couple months before. Between that and the instant problem we have had no other issues other than a slight degradation in coverage, which was actually less severe than we thought would occur.

[Bill_G]

Sounds like you have wireline control of the two repeaters. No comparator indication and it's not heard over the air. That suggests the beeps are not coming from the repeaters either. Do the consoles get a call light when it occurs? If so the problem originates before the consoles but after the receivers. That leaves the comparator.

[n9jig]

It IS coming over the air.

[The Pager Geek]

The only other thing that comes to mind is that we reprogrammed to Narrowband a couple months before. Between that and the instant problem we have had no other issues other than a slight degradation in coverage, which was actually less severe than we thought would occur.

Well isn't this a fun problem...

Other than what was done above (wide to narrow) nothing else was changed?
Where was THAT recording taken from? Conference bridge?
Where is the function tone in the audio coming from? Console or Digitac?

Here's an interesting thing... during the function tones, the beeping is overridden by the function tones. IE: The function tones are either being caused by the device, or "below" the device.

While the beeping is occurring, is there any way to make them go away? Subscriber transmits, console transmits?

tpg

[Bill_G]

It IS coming over the air.

Doh! You're right. Ya said so in the very first msg. So, the Quantars are programmed to send alarm tones over the air and down the wireline. But! Nobody seems to be able to notice which line it is on the comparator. That is strange. If any of the rcvrs or one of the two repeaters were to drop status tone so they could send in an alarm, and make it past the comparator which will stay muted until it has a carrier det, you would see the activity light on the comparator, and see a call indication on the consoles. You should verify that the comparator remains muted until carrier det by injecting a tone at one of the inputs without dropping status tone. If that is true, then it is very probably the comparator making the beeps. If it is false, then you could be enjoying beeps on the phone lines connecting the sites back to your dispatch.

[n9jig]

The only other thing that comes to mind is that we reprogrammed to Narrowband a couple months before. Between that and the instant problem we have had no other issues other than a slight degradation in coverage, which was actually less severe than we thought would occur.

Well isn't this a fun problem...

Other than what was done above (wide to narrow) nothing else was changed?
Where was THAT recording taken from? Conference bridge?
Where is the function tone in the audio coming from? Console or Digitac?

Here's an interesting thing... during the function tones, the beeping is overridden by the function tones. IE: The function tones are either being caused by the device, or "below" the device.

While the beeping is occurring, is there any way to make them go away? Subscriber transmits, console transmits?

tpg

We tried having he console operator key up to clear it, in fact that is the function tones you hear. We also tried a portable, same lack of joy there.

The recording was off the conference bridge, so it is the same audio that the dispatcher hears. We take it there so that we can record the console intercom audio as well as the OTA traffic.

[Bill_G]

We tried having he console operator key up to clear it, in fact that is the function tones you hear. We also tried a portable, same lack of joy there.

The recording was off the conference bridge, so it is the same audio that the dispatcher hears. We take it there so that we can record the console intercom audio as well as the OTA traffic.

Can a mobile / portable user talk through the beeps, or are they fully interrupted?

[n9jig]

Well, we are pretty certain it is coming from one of the 5 consoles on the conference bridge, or from one of the line amps attached to the them. It isn't coming from any of the satellite receivers since there is no indication on the comparater. There are no notations in the Quantar logs either, so that probably rules that out. In addition, there seems to be no reference to a continuous beeping like that in the service manual. That leaves the consoles and associated phone lines.

On our system there are 5 consoles. 2 are year old ModuComs, one is a NineOneOne system, one is a Gold Elite and the other an old CentraCom II.

Unfortunately (or not) the beeps seem to have stopped for now, and when they did occur we have not been able to get downstairs to the repeater room in time to pull conference bridge cards. If/when the beeps reoccur we will try and get there to pull the cards one by one til it stops to see if we can isolate the source.

Thanks for the help guys!