BCD436HP/BCD536HP: DMR CAP ?

[joejo95]

I am picking up what I think is a new DMR system for my country's school bus. I am using just one freq and the scanner is showing CAP. So can a CAP System just use one freq. I ask cause I am not getting any audio but I do get the color code to show.

 

[dave3825]

Do you have the Dmr paid upgrade?

 

[joejo95]

Yes

 

[Whiskey3JMC]

I am picking up what I think is a new DMR system for my country's school bus. I am using just one freq and the scanner is showing CAP. So can a CAP System just use one freq. I ask cause I am not getting any audio but I do get the color code to show.

Yes it is possible for a CAP+ system to only utilize one frequency. However there are times when LRRP messages may be misidentified by the scanner as CAP+. Best way to rule this out if the frequency(ies) isn't(aren't) identified in the RR database is to consult the agency's FCC license to try the other listed fixed base frequencies. Basically CAP+ has a rest channel which emits a data burst every few seconds. After a period of time the rest channel may switch to another frequency on the license. Once you determine which frequencies on the license are indeed active then you'll need to run LCN finder to determine proper LCNs so the system can be tracked properly. Be sure to submit your findings to the database once confirmed. Hope this helps

 

[joejo95]

There is only 2 frequency in the system by the license so I think will add both and see what happens. ProScan is showing some of the transmissions as ENCed put not all of them. That was why I was asking if a DMR CAP system will just use one freq cause everything I have read says it is a trunked system.

 

[joejo95]

Thank you sir. That does help.

 

[dave3825]

Is Proscan listing any color codes? If any other entities in the area are using the same freq, you will need the color codes.

 

[joejo95]

Yes it is showing CC 1 and one TG 16

 

[joejo95]

The school closed today for weather so I do not know if there testing or installing equipment. The system has been analog.

 

[Ubbe]

Program it as One Frequency Trunk and it will monitor both slots without considering any trunked channel numbers. Only if a CAP system uses two or more frequencies will you need to program correct LCN numbers in a MotoTrbo system mode to follow calls. But even then you could probably monitor both frequencies using OFT without missing much.

If you listen in analog mode, do you hear the idle data bursts that tells that it has a control frequency and are using trunked mode?

/Ubbe

 

[joejo95]

In analog mode I do not hear the data burst you are talking about. That is why I am thinking it is just a one frequency CAP system. I stopped getting anything after about a hour so I am hoping they started back up tomorrow cause it is a school day and they were out due to weather today.

 

[Whiskey3JMC]

I do not hear the data burst you are talking about. That is why I am thinking it is just a one frequency CAP system.

One frequency CAP+ freqs still emit data bursts when idle

 

[joejo95]

Ok I did not know that. This maybe a dumb question but can they use analog and DMR on the same freq. at the same time.

 

[werinshades]

Program it as One Frequency Trunk and it will monitor both slots without considering any trunked channel numbers. Only if a CAP system uses two or more frequencies will you need to program correct LCN numbers in a MotoTrbo system mode to follow calls. But even then you could probably monitor both frequencies using OFT without missing much.
/Ubbe

This is not correct on Uniden Cap+ system programming. If I program any known Cap+ system as One Frequency Trunk (OFT), it will not track it properly even if it's only a 1 frequency Cap+ system. The rest channel will still "hang up" the scanner on 1 of 2 active slots it's using. By programming it properly, this won't happen. Experiment with LCN's 1 & 2 on the Cap+ system, and if it's not tracking, then run LCN Finder and it might show LCN's 2,3 etc. which would mean their is another frequency out there.

 

[Ubbe]

If I program any known Cap+ system as One Frequency Trunk (OFT), it will not track it properly

Correct, it will not track at all, only monitor both slots. But usually a call will stay on the same slot thru the whole call.

The rest channel will still "hang up" the scanner on 1 of 2 active slots it's using.

?? This is what NOT happens if programmed as OFT and one of the reasons to use OFT. It will only "hang" on the idle bursts if you program the frequency as conventional.

/Ubbe

 

[Ubbe]

This maybe a dumb question but can they use analog and DMR on the same freq. at the same time.

Not at the same time from a single base station. But it can switch from DMR to analog depending of what it receives, a DMR signal or a CTCSS tone. I have one such system just being put up a few weeks ago. When one mode are in use other users with the other mode are blocked and gets a busy. It can also be two different base stations on the same frequency, one in DMR mode and the other in analog mode, but then they would have problems if they are too close to each other as they will create huge interferences to each other communications.

/Ubbe

 

[ka3jjz]

This might be helpful....

Entering an Unknown MOTOTRBO system using Sentinel - The RadioReference Wiki

wiki.radioreference.com

Mike

 

[werinshades]

Correct, it will not track at all, only monitor both slots. But usually a call will stay on the same slot thru the whole call.
?? This is what NOT happens if programmed as OFT and one of the reasons to use OFT. It will only "hang" on the idle bursts if you program the frequency as conventional.

/Ubbe

It won't track a Cap+ system as an OFT, because the rest channel will transmit a data burst. Even the "known" voice frequencies rotate rest channels and eventually the frequency you have programmed will be the rest channel. If it's a known Cap+ system, program as a MotoTRBO system (As seen in Sentinel), if only 1 frequency is being used, use LCN 1. If transmissions are being missed, look for another frequency(ies) and/or run LCN Finder to confirm the LCN. If the only frequency is other than 1, start researching and looking for others.