Totally confused on 800MHz talkaround or direct communications.

[altec]

I'm confused on how the "talkaround or go to direct means" on 800MHz Comms. Is there a wiki or link to this subject on how this works. I somewhat know what it means on vhf frequencies but 800MHz is more complicated? For ex: 856.762 thru 860.762 are the primary 5 repeater channels a user is using. When they say go to "talkaround or direct" I lost the rest of the conversation.

I know you would have to be within a half mile to listen in on it but how does that work when you have 5 channels to listen in on and your scanner is set to a motorola system setup? Do you have to set the frequencies up on a conventional mode?

Also is it possible for them to use a vhf frequency using their 800MHz antenna on their vehicle? I'm confused on this because during certain busy times they say to switch to "direct" so their operations won't disturb everyone else. I heard some systems have a repeater talkaround but I think mine are using portables where you would have to be within a mile of them to hear them. They primarily use 800MHz. Any thoughts or links of this would be great! Thanks, Altec.

 

[RodStrong]

Are you referring to a trunked 800 system or a conventional repeater system? If it's conventional, then the same theory applies with VHF or UHF repeaters.

If they say "go to talkaround, or direct", they could be talking about the receive side of a repeater, or even perhaps a special simplex they have set aside specifically for car to car or radio to radio comms that is completely different than the frequencies they are normally on.

And regarding your other question, I suppose somone could physically talk on VHF out of an 800 antenna, but that would be abnormal.

 

[CCHLLM]

Well, kinda hard to say what it really means on a trunked system. As Rod posted, the normal logic might well be the same in their minds as VHF/UHF, but trunked systems don't really make that an option in the same sense as conventional repeater systems. In most places I've heard that used on a trunked system, "talkaround" or "direct" means a pre-arranged simplex tac channel, and the designation seems to be just a carryover from their previous conventional systems. I've seen simplex tac channels alpha tagged as "Direct 1", "Direct 2", etc., or "Direct1Alpha", "Direct1Bravo", etc. That tells me that it's more likely dependent on local preferences and system configurations.

 

[altec]

I forgot to tell you it was a trunked 800MHz system. My bad. Yes it is trunked. Thats what confuses me, trunked vs talkaround. Also I have tried monitoring the trunked frequencies in a conventional setup but I get heavy feedback. Lots of noise that seem to make your ears cringe. I'm assuming its the powerlines or something like that. It works perfect though in a motorola setup.

 

[wlmr]

Just to muddy the waters, another option is to create a trunking talkgroup the dispatchers don't normally monitor and just use it for radio to radio stuff.

Direct or Talkaround is a very generic term that has been done LOTS of different ways.

In order to get a more accurate answer, you'll have to ask in the State Forum where the system you are monitoring is. Someone there may know exactly how the system you're listening to is set up. All we can do is give the standard answers - but we're still guessing ourselves.

 

[Astrak]

I think it really depends on the system and how it's set up, but I would say talkaround is a talkgroup and direct would be a simplex frequency. Radio's capable of trunking can also operate on conventional repeater and simplex frequencies as well as trunking systems

 

[kb2vxa]

On a trunked system it's not a talk group in the normal sense, I can't recall the specifics offhand but it involves a "00" when you program it in a scanner. In any case the conversation goes direct car to car bypassing dispatch. Maybe someone could elaborate?

 

[Astrak]

Are you talking about I-calls?

 

[zz0468]

A few points to ponder...

1. Trunked radios are also capable of conventional operation.
2. True direct "talkaround" requires transmission and reception on the same frequency, not paired as in repeater operation. This is a non-issue for the radios. They can just do it.
3. What the users call "direct" or"talkaround" may or may not be what they say it is. They don't always know.
4. There are a number of conventional frequencies that could be utilized along side a trunked system to give true direct capability.

 

[flecom]

Are you talking about I-calls?

this is what i was thinking, either that or they are going to conventional/simplex channels...

i really doubt they are using a different band also

 

[peterjmag]

What trunked radio system are you talking about?

 

[Astrak]

this is what i was thinking, either that or they are going to conventional/simplex channels...

i really doubt they are using a different band also

I'm not sure what type or receiver you are using but you would be able to monitor with a GRE, RS, or a uniden scanner. I don't know much about Uniden but with the GRE or RS new models you could set a private wildcard object so you can monitor icalls. Simplex would be a little different obviously but just try programming in some repeater outputs from the trunked system you are listening to as conventional and monitor away.

 

[ILMRadioMan]

Well I wont beat the "direct" or "talkaround" dead horse anymore.

However, in regards to VHF on an 800 MHz antenna: Its "possible", but you will have a high amount of SWR. This will cause the PA in the radio to blow out.

It wont really hurt it once or twice, but anything regularly will kill it.

 

[APTN]

A few points to ponder...

1. Trunked radios are also capable of conventional operation.
2. True direct "talkaround" requires transmission and reception on the same frequency, not paired as in repeater operation. This is a non-issue for the radios. They can just do it.
3. What the users call "direct" or"talkaround" may or may not be what they say it is. They don't always know.
4. There are a number of conventional frequencies that could be utilized along side a trunked system to give true direct capability.

Some users do use the term "talkaround" incorrectly. I tried to explain to some dispatchers I know that they were not changing frequencies, but merely talkgroup affiliation when they turned the dial. They sill did not understand the concept of trunking. :roll:

 

[ILMRadioMan]

They never will APTN. Nor do they really need to, for that matter.

 

[zz0468]

They never will APTN. Nor do they really need to, for that matter.

They don't need to understand it to the level that they could trouble shoot it, but they very much need to understand how to use it and what it's capabilities are. I've seen too many mutual aid situations go sideways for lack of communications. The systems take a bad rap for not being interoperable enough, but the whole time everyone had conventional talkaround capability and just didn't know how to use it.

It's a training issue more than anything. But I disagree that they don't need to understand. They do.

 

[APTN]

They don't need to understand it to the level that they could trouble shoot it, but they very much need to understand how to use it and what it's capabilities are. I've seen too many mutual aid situations go sideways for lack of communications. The systems take a bad rap for not being interoperable enough, but the whole time everyone had conventional talkaround capability and just didn't know how to use it.

It's a training issue more than anything. But I disagree that they don't need to understand. They do.

I'm somewhere in the middle, because I agree ILMRadioMan and zz0468. Users don't need to know every little feature, but they should have a basic understanding as zz0468 describes, and they should be able to fix minor malfunctions (perhaps inadvertent settings changes caused by wrong buttons being pushed) without calling external radio techs. Besides, they could learn a lot just by spending a little time browsing this site.

 

[ILMRadioMan]

Ok we are talking apples and oranges.

I agree with you zz.

But please read what was said:

Some users do use the term "talkaround" incorrectly. I tried to explain to some dispatchers I know that they were not changing frequencies, but merely talkgroup affiliation when they turned the dial. They sill did not understand the concept of trunking. :roll:

I was responding to what APTN had said.

IMO:

1) It doesnt matter at all if they use the term talkaround. Its the idea that matters.

2) They dont need to understand the concept of trunking. Yes they need to understand patching, interoperability, etc... but trunking? I dont think so.


So while I definitely agree with what you SAID zz. I think you took it down a rabbit-hole.

 

[ecps92]

As others have said

Talk-Around or Direct could be a Talk-Group on the TRS, it also could be a Conventional channel, either Simplex or Repeater. All depends on how the
original design was made. Talk-Around aka T/A could be Simplex on a conventional 800 Rptr as well.

Also Pvt-Call, which creates an on-the-fly T/G [Motorola] for two users to chat. Many Sys-Admins have disabled this feature as it locks up a frequency on a system. [Scanners call this I-Call, as it's an Individual unit to unit]

Here in Boston our MSP have
a.) Talk-Around as a Talk-Group on the TRS
b.) Direct as a Conventional Simplex Channel

What other 800 Frequencies does your Agency use that are not part of the TRS??

I'm confused on how the "talkaround or go to direct means" on 800MHz Comms. Is there a wiki or link to this subject on how this works. I somewhat know what it means on vhf frequencies but 800MHz is more complicated? For ex: 856.762 thru 860.762 are the primary 5 repeater channels a user is using. When they say go to "talkaround or direct" I lost the rest of the conversation.

I know you would have to be within a half mile to listen in on it but how does that work when you have 5 channels to listen in on and your scanner is set to a motorola system setup? Do you have to set the frequencies up on a conventional mode?

Also is it possible for them to use a vhf frequency using their 800MHz antenna on their vehicle? I'm confused on this because during certain busy times they say to switch to "direct" so their operations won't disturb everyone else. I heard some systems have a repeater talkaround but I think mine are using portables where you would have to be within a mile of them to hear them. They primarily use 800MHz. Any thoughts or links of this would be great! Thanks, Altec.

 

[kb2vxa]

"Are you talking about I-calls?"
Yes Astrak, I just couldn't recall the name of it. That's the usual car to car "channel" on a trunked system.