DMR and frequencies

[Clats97]

I have a question about programming a system into a radio or scanner. In the table below, it shows 2 frequencies that are the same, under slot 1. Then you see 2 frequencies that are the same under slot 2.

I'm not sure I understand this. It's a dmr system. My understanding is that DMR trunked systems use the same receive and transmit frequency. So what's up with there being 2 frequencies under one site? If I were to program it with the frequency for slot 1 and leave it at that, will I only hear half the traffic because I didn't program in the frequency for slot 2?

Sorry if my question is confusing, I'm struggling to put this in words. Basically I don't understand why there are 2 frequencies and I'm wondering how that would affect the programming Intp a radio or scanner.

In the CPS programming software, you must add the talkgroup, then you add a channel, and input the transmit frequency, receive frequency, colour code, and slot.

But because there's 2 frequencies, it's confusing me.

Do I create the talkgroups, then add a channel with the first frequency, then add a channel with the second frequency?

How do I determine which talkgroups I link to which frequency? Or do I esentially have to program everything twice, so the talkgroups, the first frequency, the second frequency, and esentially have them mirrors of eachother?

Here's the chart:

LCNLSNFrequencyColor Code
01 1 123.456 5
01 2 123.456 5
02 3 789.101 5
02 4 789.101 5

If you don't understand what I'm asking, I will do my best to clarify. Basically the 2 frequencies under 1 site is confusing me and I'm not sure how to program.

Thanks.

 

[RaleighGuy]

@Clats97 first, this is not a general scanning question and would be better placed in a programming forums for your radio or scanner, secondly, if the system is in Radio Reference database please provide a link to make it easier to see what you are talking about. Finally, there is a difference between programming a radio and a scanner, as well as different programming for each, it would help us to help you if you identify what you are trying to program and then (as I said in the first suggestion) click on REPORT in the lower left of your original post and ask for this to be moved.

Please do not start a new post as double posting is discouraged in the forums.

 

[Whiskey3JMC]

My understanding is that DMR trunked systems use the same receive and transmit frequency.

So what's up with there being 2 frequencies under one site

Wrong! They have input frequencies like every other repeated signal. Where you seem to be confused is how one DMR frequency is typically divided into two 6.25kHz timeslots (1 & 2 respectively) so traffic from two talkgroups can be carried on the same frequency simultaneously if need be, this is why on a trunked system's frequency map you see the same frequency listed twice, each with its own LSN or Channel ID. In the case of MotoTRBO CAP+ your LCN for the two-slot pair will always be the higher, even numbered LSN divided by two, as is the case with the example you provided in your opening post

TDMA - The RadioReference Wiki

wiki.radioreference.com

 

[Clats97]

@Clats97 first, this is not a general scanning question and would be better placed in a programming forums for your radio or scanner, secondly, if the system is in Radio Reference database please provide a link to make it easier to see what you are talking about. Finally, there is a difference between programming a radio and a scanner, as well as different programming for each, it would help us to help you if you identify what you are trying to program and then (as I said in the first suggestion) click on REPORT in the lower left of your original post and ask for this to be moved.

Please do not start a new post as double posting is discouraged in the forums.

OK I will try to do that right now... My bad I looked at the different sub forums and thought this was most appropriate... I'm actually asking about both programming into a scanner AND a radio because I want to see what picks up more traffic, the scanner or the radio. The software allows me to put it into rx mode

 

[Clats97]

Wrong! They have input frequencies like every other repeated signal. Where you seem to be confused is how one DMR frequency is typically divided into two 6.25kHz timeslots (1 & 2 respectively) so traffic from two talkgroups can be carried on the same frequency simultaneously if need be, this is why on a trunked system's frequency map you see the same frequency listed twice, each with its own LSN or Channel ID. In the case of MotoTRBO CAP+ your LCN for the two-slot pair will always be the higher, even numbered LSN divided by two, as is the case with the example you provided in your opening post

TDMA - The RadioReference Wiki

wiki.radioreference.com

I'm not sure I understand. There's a system in my area that I monitor that receives on the same frequency it transmits on. It's capacity plus single site. But in all honesty that may not always be the case and my case in point is my original post lmao. There's 2 freqs in one site when all the other times I've done dmr the rx and tx is the same. That's why I'm confused right now and asked this question. And the 1 frequency is on slot 1 and the other is in slot 2, so it's not one freq being divided into 2 because one slot goes to freq 1 and 1 slot goes to freq 2... You don't further divide slot 1 and 2 no?

 

[littona]

Repeaterbook.com - Understanding DMR for the New Guy

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