Can someone explain as to why simply monitoring a DMR frequency, whether it is a trunked frequency or not, is so difficult on the 436HP compared to the TRX-1? You simply enter a frequency on the TRX-1 and it will monitor it. The 436 however seems to need it programmed as a single frequency trunked system. Does a true conventional programming even exist on the 436 for NXDN and DMR? For instance after finding a DMR frequency on the TRX I tried to just manually tune to it on the 436. The screen would show details of the system but would not decode voice?? Why? I am finding monitoring DMR and NXDN to be much easier with the TRX even thought it is not truly trunking.
BCD436HP/BCD536HP: DMR single frequency programming
- Thread starter frazpo
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You do not get the full functionality of DMR or NXDN on that TRX. You can not get all of the TGs in use on the Time Slots on an DMR system thus the ability to monitor only specific TGs among other things on the TRX. You can just conventionally monitor an DMR system on a 436, just set the Tone setting to digital and put in the Color Code, or set to search. You will not know which user group is on but you can do this. Same on NXDN. But if you want the full details you must program it as an OFT. And considering that most DMR conventional systems are basically a trunked system, especially IP Site Connected ones.... Its logical to set it up as such.
While Milf excellently lays out the differences between the 2 let me be more to the point:
--Whistler half @sses DMR/NXDN which is why they are "easier" to get up and running.
--Uniden gives you full DMR/NXDN trunking which allows monitoring of specific TGs and Radio IDs.
Marshall KE4ZNR
troymail
Silent Key
OK , This all helps. I think one thing worth noting is that I don't have any elaborate systems to monitor. Mainly just 1-2 frequency systems. I am experimenting on which options receives the best.
I have a multi frequency NXDN system that the 436 follows beautifully on. Hope to see the same results on DMR. Thanks !
I have a multi frequency NXDN system that the 436 follows beautifully on. Hope to see the same results on DMR. Thanks !
Ubbe
Member
Whistler and Uniden have different patents and use different techniques to monitor digital systems.
Some systems will let the Whistler excel and on other systems the Uniden will perform better.
Try and use each scanner where it perfomes best.
Generally speaking on a big trunked system the Uniden will do better. With medium and small systems that have low to medium traffic intensity, and not use super many frequencies on each site, the Whistler is doing a better job.
I don't know what they mean by saying that the Whistler doesn't have full functionality in DMR. It often performes better than a Uniden that skips active conversations way too often.
If there are a private mobile-mobile conversation in a system the information on the control channel are only sent once and if you do not scan that frequency when the call is set up you will loose it totally with a Uniden scanner while the Whistler will let you monitor all private calls at all times as it scans the actual active voice channels.
I have commercial DMR radios monitoring systems and the Whistler never miss a talk group call while the Uniden sometimes skips the call setup and comes in late or continues to scan to the next system as if it never where a call on the system.
Whistler have other issues like a small display with minimal information, terrible keypad buttons, a squelch that lives it owns life, bad RF performance in some frequency bands, no multiple search ranges, CTCSS/DCS search are awful. But instead have an excellent audio recording system, superior LED light indication, detachable front panel, great audio quality from speaker, discriminator output, parameters like delay can be set to any value up to 60sec, a sweeper function that catches transmissions from a great distance.
You really need scanners from both Uniden and Whistler to be able to satisfy most of your needs.
/Ubbe
jonwienke
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You're always better off programming OFT over programming conventional freqs. You can set the location(s) of the system to accurately reflect the coverage area of each transmitter, as well as the usage area and other information for each talkgroup. You can program labels for individual unit IDs. And despite all the extra options, the scanner will never scan a OFT system slower than the corresponding conventional freqs.
jonwienke
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The kind of systems being discussed here don't have control channels. But on systems that do, following the control channel generally misses less traffic than scanning the voice channels. If you're holding on a site, the scanner is listening to the control channel, and only switches to a voice channel then the control channel announces a transmission in progress. If you're not following the control channel, you're still scanning all the site frequencies, even if doing a site hold, and will miss the beginning of transmissions when the scanner is listening to another site freq when a transmission starts.
It's also worth noting that you can force a Uniden to scan voice channels on a system, instead of following the control channel, by programming the system as One Frequency trunked rather than trunked. So if private call traffic is important to you on a particular system that only broadcasts private call info on the control channel once, that's an option.
lu81fitter
Member
I know I don't have the same radio (996P2) , but there is a department near me that uses a DMR channel. The channel is set up to either use it analog or DMR. I have one analog system programmed in my radio with that channel. If they happen to use DMR mode when I am scanning it with the analog system, it still picks up the transmission and says "DMR" in the lower right hand corner. Must be different on the 436. I do not have any color codes or slots on that channel. It is programmed simply as conventional.
jonwienke
More Info Coming Soon!
The x36 scanners are the same, you can pick up analog or digital traffic on a conventional channel if you don't program a tone/NAC/CC/RAN. You just can't program talkgroups for digital traffic when programmed as conventional.
It is good to know that I’m not imagining the issues and the behavior I’m seeing just isn’t specific to my scenario.
Also, is there a DMR type of system that uses a CC as a voice channel also? I swear I’m seeing this in a newer system here locally.
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Also, is there a DMR type of system that uses a CC as a voice channel also? I swear I’m seeing this in a newer system here locally.
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troymail
Silent Key
You could notice a "idle burst" on a DMR system/frequency every few seconds and eventually hear a voice call on that frequency. I believe the bursts inform the radio of the frequency that should be used for the next voice call. It moves to a different frequency as frequencies are used. These bursts are one of the things that cause problems on Uniden scanners when programming as conventional because it causes the scanner to never release back to scan other things.
Keep in mind that DMR also allows for data to be sent on the same frequencies. This data could be as simple as a text message or feeding apps on the devices.
On a related note, NXDN systems I've monitored use the (full time data) control channel to carry voice. A local system here is mostly (at this point) a single frequency that switches to voice and then back to control signal constantly. I saw this same thing on a Maryland system as well. On a 4 frequency NXDN system in Philadelphia, the control channel frequency was used as "overflow" - once the 3 "voice channels" were all busy and a 4th users wanted to transmit, voice temporarily replaced the control channel signal. Of course, this meant that no other talkgroups on the system could be activated during that time....
Very helpful. The first paragraph illustrates exactly what I have noticed and the problem I found with programming that type as conventional. These DMR and NXDN systems seem to work so much differently then your standard P25 systems where there is simply a CC and then multiple VC to program.
Still learning. This thread has definitely helped me understand the differences between the systems and the best way to program them. I seem to have a variety of different DMR and NXDN systems here locally.
troymail
Silent Key
Each radio has it's strengths and weaknesses.
The Whistlers are great because I got DMR and NXDN without whipping out my credit card to get those modes and because they make it easy to program and monitor these digital modes without much hassle. I don't need to know if it is trunked or conventional - I don't need to figure out what the LCNs are first. This allows users to very easily start listening even when only limited information is known about the system (i.e. you don't know all the frequenquencies, you don't know the LCNs, etc.) They properly handle conventional DMR attributes like slot, color codes, etc when programmed as conventional. The radios perform fairly well on smaller systems but will struggle a bit on trunk DMR or NXDN systems that have alot of frequencies.
Unidens will tell me if the frequency is conventional DMR (even though they don't allow it to be programmed properly as conventional), CON, CAP, etc. The programming is more tedious - even more so when trying to figure out a new system. However, they can perform better on those larger (more frequency) systems... I say "can" because you still need solid reception of the system like other trunk systems because without good reception of the control channel/indicators, the radio won't switch to the voice transmissions.
FWIW - I'm monitoring a single frequency multi-state NXDN system site in my area on 3 different radios and none of them are picking up 100%. Many times I only hear the transmission on 2 of the 3 radios but it "rotates around" among them...
The Whistlers are great because I got DMR and NXDN without whipping out my credit card to get those modes and because they make it easy to program and monitor these digital modes without much hassle. I don't need to know if it is trunked or conventional - I don't need to figure out what the LCNs are first. This allows users to very easily start listening even when only limited information is known about the system (i.e. you don't know all the frequenquencies, you don't know the LCNs, etc.) They properly handle conventional DMR attributes like slot, color codes, etc when programmed as conventional. The radios perform fairly well on smaller systems but will struggle a bit on trunk DMR or NXDN systems that have alot of frequencies.
Unidens will tell me if the frequency is conventional DMR (even though they don't allow it to be programmed properly as conventional), CON, CAP, etc. The programming is more tedious - even more so when trying to figure out a new system. However, they can perform better on those larger (more frequency) systems... I say "can" because you still need solid reception of the system like other trunk systems because without good reception of the control channel/indicators, the radio won't switch to the voice transmissions.
FWIW - I'm monitoring a single frequency multi-state NXDN system site in my area on 3 different radios and none of them are picking up 100%. Many times I only hear the transmission on 2 of the 3 radios but it "rotates around" among them...
Ubbe
Member
I've seen that option in some systems but users normally don't want that enabled as higher priority calls like emergency calls and all kind of status messages also are ignored. Maybe emergency calls can brute force themselves into a conversation and make the system restore the control channel?
/Ubbe
troymail
Silent Key
Agree - perhaps there is some type of interrupt - don't know. For that system, however, from my monitoring, it was fairly rare that all frequencies became voice and when it did, it was for a very brief period as most voice calls were very short.
The weird one is this single frequency system in my area. Most of the activity is "over the network" from another state. Given the activity, I suspect there are other frequencies assigned to the site (or there will be) and I just haven't found them yet - but certainly not for a lack of trying. In it's current mode, it would seem that when a voice transmission actively replaces the control channel that other talkgroups would get some type of "bonk" but maybe only at the system level. Perhaps it's just a system setup and troubleshooting mode in this case as they test and build out the system. Just part of the mystery and fun of the hobby I guess...
This response sums up my experience with the 436 and the TRX-1 while trying to monitor different types of systems. Like you said reception is a big deal with the 436. The trx will outperform on a trunk system until you get the reception you need (CC) and then it is rock solid. Like someone mentioned each radio has its advantages depending on what you are trying to monitor.
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