close call for DMR freqs

[gary123]

I was wondering if it is possible or practical to create a second close call option setting?

The idea is to increase the time closecall looks at activity on a found frequency. Currently it ignores anything less than 30ms although I am not sure of the exact timing used. I know that increasing the time will result in a lot of possible false hits but anyone using it should be ready to accept the issue. This would make locating new DMR channels and services easier.

Since I am doing a wish list is ity possible to change the sensitivity of closecall? The current settings are good for cities but in the country there is less rf noise and a higher sensitivity would be useful.

 

[UPMan]

The nature of the method used for Close Call means that it will never be able to reliabely detect a DMR simplex signal. It relies on comparing multiple short samples. An intermittent signal will never look coherent.

 

[gary123]

UPman

Thanks for the info.

I know that the method would not be reliable, Many services do use repeaters and locating these repeaters is a pain. In many cases it is necessary to park near the service and directly search the suspected band segments hoping for a hit. Currently I use a SDR as a limited spectrum analyzer and have found numerous DMR freq by this method. The Canadian TAFL (I am in Canada) is almost useless and locating DMR users is a uphill battle.

The other item I suggested, a selectable city/rural mode for close call is that a possibility?

 

[pro106import]

DMR Search

OK here is how I do it with my Whistler scanner. I am sure the same procedure would work wit a Uniden except I'm sure the software looks different. But you can get the concept and incorporate the idea into your Uniden Software.
However, I am not sure about the Uniden's as far as DMR receive. With the Whistler, if you set a conventional frequency to DMR mode, it will not stop on any other modulation that may be on the frequency when it samples it. So my radio will just scan by anything that is anything other than DMR when I set it up as what follows:

First set up a bunch of systems in 1 MHZ. or 2 MHZ. chunks in the most popular DMR ranges.



Now use Excel to produce a list of all freqs in that range as seen partially in this photo, and import them into your software (not sure how you do that with the Uniden software, but with EzScan there is an "import from clipboard" feature which makes it stupid simple :wink: )



And I set all freqs to RECORD so I can do unattended searches and see what it found. Also set the Color Code and Talkgroups and Slot to ANY so the radio will stop and record any DMR signal regardless of those.
Do this for each range and now you can let her go!
I know it takes a while initially, but you only have to set it up once.
Enjoy, Bob

 

[SCPD]

Where do you put the "ranges" in the software? (as seen in 80-96 above)

 

[pro106import]

Where do you put the "ranges" in the software? (as seen in 80-96 above)

IN EzScan those are the Alpha tags for the systems on the General Configuration Settings

 

[gary123]

Pro106import; I am using a similar process. I use a SDR stick to actually look at the spectrum in small chunks and log any new activity that way. I have used the scanner in analog mode only to search small segments then review the activity heard.

I was looking for something in the CC function that might have been more DMR friendly but given the way that CC and the DMR systems function I see UPmans point that it simply is not practical to modify the CC operation to accommodate DMR.

 

[racingfan360]

I've been looking for a reliable method to hunt out DMR [simplex] signals for some time now.....I often attend events where I'll have a good idea which band the radios are operating on, but frequencies are unpredictable and the DMR radios operating in simplex just simply 'fly under the radar'. I tried many different tools and approaches (SDR, close call, digital frequency counters etc).

Without doubt, the best method I've found is using the Search and Store function with custom bands set. And while I've tried this with various different scanner models (including most of the Uniden portable models made in the past 10 years), the unit that stands out as the best is the SC230. I don't understand why that's the case, but it seems to work really well. Performance is obviously helped if you get the custom search bands right, the right step size for a fast search, a good antenna and proximity to the transmitter. It obviously just finds the frequency, and you'll get other hits from non-DMR signals too. But I simply use the 230 to hunt down frequencies, and use this frequency info with say a BCD436HP to listen in.

When I bought my first uniden, I did think close call was its best feature: its the one feature most people rave about....but personally, I've found the search and store is just as useful if not better.

I should add I've never had an issue with finding DMR repeaters.....I've found close call works fine on any of the undien models I've owned, and just as reliable for this purpose as it is for analogue or NXDN radios, be they repeated or not. Again, using Search and store with custom search bands is also very good for this, if not better.

It's also a reason why I was so disappointed to see that Uniden dropped the search and store function on the 436 :-(

 

[SCPD]

yes

IN EzScan those are the Alpha tags for the systems on the General Configuration Settings

View attachment 56776

Yes but can you search those ranges and turn them on and off OR
are those ranges just places you've stored frequencies in that range?

 

[pro106import]

Yes but can you search those ranges and turn them on and off OR
are those ranges just places you've stored frequencies in that range?

yes you can select just one range to "scan". Maybe you just want to look for DMR activity from 451 to 453. So just select bank 80 and lock everything else out. You will continuously scan every freq. between 451 and 453 for DMR activity and log and record it. All night if you want while you sleep (if you can).
You are actually scanning every frequency in the range because you store them as separate frequencies, as you would your local list of frequencies. This way you can lock out the ones you identify if you like or just scan the whole range, or several ranges at the same time.
It is not a search range. The trick is to store the frequencies yourself in a system (using that Excel spreadsheet to obtain them) and SCAN them as you would any other frequencies. But they are all set to receive DMR modulation only, so they will not stop on anything else.
I have been doing basically the same for P25 signals for years with my BCD396XT's. Same concept, different radio and modulation and frequency range. My P25 interest is from 162-174 and 408-420. Nuff said.

 

[motogo2000]

Now use Excel to produce a list of all freqs in that range as seen partially in this photo, and import them into your software (not sure how you do that with the Uniden software, but with EzScan there is an "import from clipboard" feature which makes it stupid simple :wink: )

View attachment 56775

And I set all freqs to RECORD so I can do unattended searches and see what it found. Also set the Color Code and Talkgroups and Slot to ANY so the radio will stop and record any DMR signal regardless of those.
Do this for each range and now you can let her go!
I know it takes a while initially, but you only have to set it up once.
Enjoy, Bob

Can you please attach the excel format so It can be imported properly by ezscan? I have no luck to do that.. Thank you..

 

[pro106import]

Can you please attach the excel format so It can be imported properly by ezscan? I have no luck to do that.. Thank you..

OK the excel file is for 451-453
I had to zip it for it to accept it
View attachment 451.zip
just highlight all 3 columns and click copy and then go click "import clipboard" on the conventional tab of EzScan


Name the 3 columns as seen here:


The rest of the options like Record and delay you have to change once the freqs are imported into the software
Good Luck

 

[motogo2000]

OK the excel file is for 451-453
I had to zip it for it to accept it

thank you very much for your help.. It works now..

 

[ynot58]

Close call

Whistler trx 1 and 2 use spectrum sweeper as close call. It sweeps through the bands you enable in the sweeper settings and catches all signals including dmr and nxdn outputs and inputs. It sweeps very fast and adjusted using squelch. Longer range than close call uniden and turning squelch down makes it catch only very close signals. Tried with nxdn and dmr and shows input frequencies with talk groups and other detailed info

 

[Voyager]

Spectrum Sweeper cannot detect DMR inputs. It can pick them up as a result of a hit on another frequency, but the Nearfield receiver cannot detect them just the same as Uniden's Nearfield receiver cannot detect them.

When you hear DMR inputs on Spectrum Sweeper what is happening is this:

SS sees a hit on a frequency and initiates a 1 MHz search (that's how they get around the Close Call patent). At that point the receiver is as sensitive as any other Search function and it will pick up any signal that is above the squelch threshold INCLUDING signals other than the one that triggered the hit. If it finds a DMR input and happens to be tuned there during the search, it will stop on it. It's just as likely it will miss the DMR input since it only transmits half the time. It's a matter of odds.

So, when you "get a SS hit on a DMR input", it was not triggered by the DMR transmission, but by some other constant-carrier signal.

Outputs (both DMR and NXDN) and NXDN Inputs are constant carrier modes that can be detected by Nearfield receivers, so both SS and CC will hit on those.

 

[G7HID]

Somehow I don't think that is how it works, my TRX1 will detect and stop on DMR inputs/simplex frequencies with no problem - no relying on a carrier within 1 MHz...
I am told by Avera, the people who market the UBCD3600XLT (European 436) that the Uniden Close Call will not stop on a DMR input/simplex frequency because the signal is not present long enough to trigger the Close Call, to overcome this Uniden would need to modify their Close Call..

Mike

 

[Voyager]

Somehow I don't think that is how it works, my TRX1 will detect and stop on DMR inputs/simplex frequencies with no problem - no relying on a carrier within 1 MHz...
I am told by Avera, the people who market the UBCD3600XLT (European 436) that the Uniden Close Call will not stop on a DMR input/simplex frequency because the signal is not present long enough to trigger the Close Call, to overcome this Uniden would need to modify their Close Call..

Mike

Well that is how it worked when GRE had it.

Develop a new nearfield receiver? Unlikely.

 

[k3fs]

Whatever. The TRX works, and lands on freq.

 

[ynot58]

Dmr spectrum sweeper

I have sat outside many places with spectrum sweeper and locked on to dmr and nxdn input repeater frequencies with all trunk and tg info displayed including nxdn 96 and many times set search range to 896.000 - 901.000 input frequencies for 935 - 940 mhz trunk range and scans all quickly and catches all that way I only get whats close .

 

[ynot58]

Dmr spectrum sweeper

By the way uniden doesn't really do it with close call or searching repeater inputs 896 - 901. In search mode only catches dmr base inputs and not always with info displayed but trx shows all info site tg color code etc