Basic Question re Channels per conversation

[buckyswider]

Hi gang, I've read the WIKI and several of the linked FAQs and such...all good stuff, but possibly TOO good for me to glean the info I'm seeking.

We have a mixed-mode Smartnet system. 14 channels assigned to our zone. 10 sites.

How many conversations does that support (I guess to simplify the answer I'll qualify that as 'per site' assuming that users are all clustered around a single tower :0) ).

If my thinking is correct, it's 7 conversations- transmit takes one channel, and receive happens on all the othere listening radios. I'm thinking that the transmitter can't transmit on the same as the receive channel, because if they did, they receivers would hear the conversation twice- one as 'talkaround' directly from the transmit radio and again when it is repeated from the tower.

Am I thinking correctly here? Is there someplace better (meaning 'simpler') I can find this? Thanks.

 

[seamusg]

Hi gang, I've read the WIKI and several of the linked FAQs and such...all good stuff, but possibly TOO good for me to glean the info I'm seeking.

We have a mixed-mode Smartnet system. 14 channels assigned to our zone. 10 sites.

How many conversations does that support (I guess to simplify the answer I'll qualify that as 'per site' assuming that users are all clustered around a single tower :0) ).

If my thinking is correct, it's 7 conversations- transmit takes one channel, and receive happens on all the othere listening radios. I'm thinking that the transmitter can't transmit on the same as the receive channel, because if they did, they receivers would hear the conversation twice- one as 'talkaround' directly from the transmit radio and again when it is repeated from the tower.

Am I thinking correctly here? Is there someplace better (meaning 'simpler') I can find this? Thanks.

The database doesnot show the input freqs only the output - if it's a MOT system it would be 13 conversations. one channel is the control channel. so if the database shows 14 freqs for one site there are 13 voice channels and one control channel. Channels are assigned in pairs.

 

[N_Jay]

Am I thinking correctly here? .

I don't think so.

It is hard to tell if you understand the basic operation of a repeater.

Each "Channel" is actually a channel pair. One for the input to the repeater, and one for the output.

All field equipment transmits on the repeater input and listens on the repeater output for the channel it is assigned to.

If you have 14 channels (channel pairs) at a site, then you have 14 repeaters at that site.

One of these repeaters and its channel pair are used for the control channel, and the other 13 are available for assignment.

So you have have 13 people TALKING at one time and any number listening to those 13 talking.

Since conversations are made up of strings of transmissions, often with a lot of gaps, you can have more conversations as long as no more than 13 people are actually Talking (transmitting) at one time.

Hope this helps.

 

[buckyswider]

Thanks, I think I understand now. If I have ten * frequencies listed here, that's just for listening purposes....in reality there are 20 frequencies....so one 'channel' is two frequencies....

Thanks for the help!

* I don't know why I thought 14 before.....

 

[seamusg]

Thanks, I think I understand now. If I have ten * frequencies listed here, that's just for listening purposes....in reality there are 20 frequencies....so one 'channel' is two frequencies....

Thanks for the help!

* I don't know why I thought 14 before.....

If I did my math right the first four pairs should be:
Output......... Input
854.96250 - 809.0625
855.23750 - 810.2375
855.93750 - 810.9375
856.73750 - 811.7375