Check for open mic .... ??

[wabc770]

....just heard that dispatched again for the umpteenth time
after somebody accidentally keys up for a minute or so.

If you're keyed up, could you still hear such a call? Just wondering....

 

[n2mdk]

Only if your near your mobile or have a partner with a radio.It's generally portables that get keyed up accidentally.

 

[wabc770]

It's generally portables that get keyed up accidentally.

I can see that being the case - this latest incident was during a barn firefight.

I guess it would be easier to spread the word of an open mic with many other
users nearby.

Thanks!

 

[br0adband]

Trunked systems sometimes (if they're set up correctly) will let a Dispatcher override a unit stuck in transmit so the person with the radio will hear the Dispatcher talking. Not all of the systems I've ever monitored allow that, but it is a feature that trunked systems are quite capable of.

 

[hoser147]

Seems to occur more often thru the winter than other times. But know matter when you always get that extra inside conversation.............Hoser

 

[wabc770]

Trunked systems sometimes (if they're set up correctly) will let a Dispatcher override a unit stuck in transmit so the person with the radio will hear the Dispatcher talking. Not all of the systems I've ever monitored allow that, but it is a feature that trunked systems are quite capable of.

Interesting. I figured professional equipment was capable of far more than the
consumer-grade stuff I'm familiar with and just wondered if they were indeed
capable of that sort of thing!

 

[wabc770]

...no matter when you always get that extra inside conversation.............Hoser

Yep, that's when it can be especially juicy to listen - not quite so cool
and impassioned and professional!

Back when, I remember hearing many a late night chat between dispatchers
and their dispatchees on those now-forbidden 800 mhz freqs, and it was
amusing how much more raw and harsh and cynical the conversations were
vs how buttoned-down they were on the air.

 

[SLWilson]

Yes and no...

The actual answer to your question is maybe yes, maybe no, but probably no....

If it is a conventional system, straight TX/RX (Same freq) then no, the guy with the keyed mike ISN'T going to hear anything. And, even if there is someone "close" to him, they also won't hear dispatch key up because of their proximity to the guy with the keyed mike will OVERIDE the dispatcher's signal.

Now on a repeater type system, here's where you get the maybe (only if someone else close to the keyed radio can hear dispatch)...If the guy is by his lonsome, no, he's NOT going to hear the dispatcher.....

On a system such as Ohio's MARCS system, if it is programmed for dispatch overide, then the guy "should" get the message....

Like Hoser says, generally happens in the winter when the field guys are all bundled up in their jackets with their lapel mikes....

In programming on most newer equipment, you can set a time out timer for the transmit time the radio will talk w/o letting off the mike.

We have our mobiles set at two minutes, the base stations at three minutes....Anyone THAT long-winded needs to take a break anyway!!!!
Steve/KB8FAR :roll:

 

[mikeydcg2003]

I know with some of the 800 moto systems if it doesn't detect any talking for so long it starts buzzing at the person. I know my dad said he has done that before and had his radio buzz at him

 

[wabc770]

Thanks to all for the insightful points! Never considered the winter angle. Obviously, bundled up and fighting a fire in single-digit wind chills, it'd be easy to miss a keyed lapel mic.

 

[trace1]

It's generally portables that get keyed up accidentally.

Awhile back there was a system that I monitor and it was the Dispatcher that had the "open mic", happened several times over a couple of days.

 

[DaveNF2G]

It always seems to happen during major incidents. You have to wonder why the offender doesn't realize that his radio is too quiet.

 

[SLWilson]

Foot Pedal...

Awhile back there was a system that I monitor and it was the Dispatcher that had the "open mic", happened several times over a couple of days.

We have a TRANSMIT Foot pedal at each of our console positions....We have to be careful that we don't inadvertently step on them!!!

Steve/KB8FAR :lol:

 

[wlmr]

We have a TRANSMIT Foot pedal at each of our console positions....We have to be careful that we don't inadvertently step on them!!!

Steve/KB8FAR :lol:

If you use 6-wire headsets (the ones with a transmit button built into the headset cable) having one get partially pulled out can also key up a console.

The only trunking system I'm familiar with leaves the keyed up portable behind on the frequency it's locked up on and sends everyone else to a new frequency to hear the dispatcher. IF there's another person close they can help narrow down who's keyed up (in addition to the fact the dispatcher is able to broadcast the unit ID of the radio that's keyed.)

 

[slicerwizard]

Trunked systems sometimes (if they're set up correctly) will let a Dispatcher override a unit stuck in transmit so the person with the radio will hear the Dispatcher talking. Not all of the systems I've ever monitored allow that, but it is a feature that trunked systems are quite capable of.

So how does a radio that is transmitting manage to receive a signal from the dispatcher?

 

[bwhite]

So how does a radio that is transmitting manage to receive a signal from the dispatcher?

I believe the short/simplified version is that the dispatcher can remotely take over control of the portable and stop the transmitting.

 

[mdulrich]

So how does a radio that is transmitting manage to receive a signal from the dispatcher?

Through the control channel.

Mike

 

[robbinsj2]

Through the control channel.
Mike

I think slicerwizard's point is, can it really receive any sort of a signal while it is transmitting? The trunked radios I've used don't check the control channel until I release the PTT or reach the time-out period. Radios which are receiving may be checking the control channel (or data running under the audio on the voice channel) and may know when the dispatcher terminates my transmission, but I will not know.

I've found "check for an open mic" announcements sometimes helpful because my radio isn't turned up loud enough to cause feedback to the nearby open mic, and the sounds coming over it are the same I'm hearing from the local environment.

Jim

 

[bwhite]

I'm nearly 100% certain trunked radios are always receiving even during a transmission. You may be transmitting on one freq/talkgroup it is always tracking and listening to the control channel. The term I last heard used when it came to stopping unwanted open mic transmissions was "emasculating" the radio. (spelling)

 

[slicerwizard]

So when the radio's PTT timer triggers, dekeying the radio, and the control channel inhibits or regroups the radio, you come to the conclusion that a half duplex radio is somehow actually a full duplex radio?