DPD switch to digital?

rainmaka

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dallas,tx
Been using my bc370crs and uniden bct15x for year's I notice a month ago listening to police chatter has gone down on my old analogs and now atm I can only hear dispatch sometimes I can here chatter but its either a silent like someones holding the mic and not talking or broken chatter unrecognizable.Have they switch to p25 and is it encrypted or opening to monitor can anyone confirm? Just wanna make sure before I make a purchase on a digital scanner.
 

KevinC

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See this thread…

 

hiegtx

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Been using my bc370crs and uniden bct15x for year's I notice a month ago listening to police chatter has gone down on my old analogs and now atm I can only hear dispatch sometimes I can here chatter but its either a silent like someones holding the mic and not talking or broken chatter unrecognizable.Have they switch to p25 and is it encrypted or opening to monitor can anyone confirm? Just wanna make sure before I make a purchase on a digital scanner.
Dallas PD & Dallas Fire Rescue, as well as all the non-public safety agencies, are moving from their legacy Uhf channels to the NTIRN trunked system. This is a P25 Phase II system, with two simulcast sites (Dallas Layer 1 & Dallas Layer 2). You will need a digital scanner to monitor the new talkgroups. As they are simulcast, this can be a problem with any scanner other than Uniden's SDS series, one of the Unication pagers, or use one of the SDR dongles & a PC. Simulcast is extremely location specific. If you are near one of the sub-sites (transmit towers), you might not have any problems, There are a few other things to try, but often not successful. More on Simulcast is in the Wiki.
Simulcast digital distortion - The RadioReference Wiki

In some cases, the NTIRN talkgroups are still patched to the Uhf channels, but once everything is moved over, and field units are trained in how to utilize the new system, I would expect the patches to Uhf to be taken down,

Dallas County is also moving to this system, from their old Vhf channels. Here again, some of their traffic is patched from the trunked system to the old channels, but that will fade away as well. Cedar Hill, Desoto, & Duncanville have moved from their NXDN system (SWRCC) to NTIRN, and Lancaster has moved from their NXDN system to NTIRN as well.

The various non-public safety agencies for the various cities are also moving. Once everyone is moved & fully up to speed on the new system, Dallas Layer 1 should be used by the various public safety agencies, with Dallas Layer 2 used for all the non=public safety traffic.
 

rainmaka

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dallas,tx
Thank you hiegtx for the reply this explains everything and ty for the extra links! : ) Hopefully Broadcastify will update there dallas tx audio stream to new system till I can save up for a new sds radio.
 

rattlerbb01

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Thank you hiegtx for the reply this explains everything and ty for the extra links! : ) Hopefully Broadcastify will update there dallas tx audio stream to new system till I can save up for a new sds radio.
Broadcastify and the Radioreference database and wiki are all user dependent. Scanner and SDR owners provide streams with their own equipment, and listeners provide database updates to be worked. I am sure there will be plenty of support for the Dallas area streams pretty soon.
 

alexkjohnson

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I've got the DPD North Central dispatch feed up and running again, using an RTL-SDR and OP25 software. Will be fine-tuning over the next few days/weeks, so bear with as the kinks are ironed out.
 

IAmSixNine

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Im in the same boat.. testing out SDRTRunk recorder with RDIO-Scanner and just not that happy with how well the audio sounds. Got a newer computer, got better antennas for the RTL SDR dongles, set them up on a usb c hub.. still not happy with the audio. I want to continue to provide feeds but i dont want to provide a crappy feed.
 

rainmaka

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Update I went ahead and over nighted a Uniden bcd966P2 from amazon I'm having no issues picking up P25 Phase II with two simulcast sites beside's DPD being on layer 1 and 2(for me they seem to be on layer 2 on 860.7375c site) ,I'm using it with a Tram-1094 antenna getting full bars unit came with fireware version 1.10.01 my p25 threshold is at 7 I must be by a transmit towers defiantly saved me some money instead of getting a SDS and also has the option for provoice,dmr,nxdx upgrade later if needed.

 

jasonk

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Update I went ahead and over nighted a Uniden bcd966P2 from amazon I'm having no issues picking up P25 Phase II with two simulcast sites beside's DPD being on layer 1 and 2(for me they seem to be on layer 2 on 860.7375c site) ,I'm using it with a Tram-1094 antenna getting full bars unit came with fireware version 1.10.01 my p25 threshold is at 7 I must be by a transmit towers defiantly saved me some money instead of getting a SDS and also has the option for provoice,dmr,nxdx upgrade later if needed.

The biggest issue is not knowing what you may be missing. Even with an SDS scanner you typically only capture about 75% of the transmissions.
 

riverradio68

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If you have a lot of favorites in your Dallas favorites list then yes you can miss stuff because its a slow scanner compared to older "Hyper Scan" Scanners. BUT if you only have DPD in that one list and nothing else in scan, you can get upwards of 95% of the traffic.
 

hiegtx

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Have a BCD 436 HD is that a good scanner for Dallas can anybody help or don't need to upgrade to the SDS 100
What part of Dallas are you in?

Simulcast distortion is extremely location specific. Even to the point that a move of only a foot or two, inside your house, can make all the difference between decent receptor, or practically none at all, or only a garbled mess.

I am using one of my 436HPs to monitor the system & keep track of any new talkgroups. I have it laying flat on my desk, with a Diamond RH77CA antenna. It's doing reasonably well, and gets very nearly the same reception that my SDS200, a couple feet away,

At a fixed location, you may have to try various places in your house, to see if you can find a sweet spot where it works. Metal siding, or foil backed insulation in the walls, can give you a spot where the scanner is only getting the signal from one sub-site and receives well. Sometimes, something else, like a metal file cabinet, or a refrigerator on the other side of the wall, helps create a spot where it may work. Hills & clusters of taller buildings between your location & the various transmitters may also help create a space where it will work. You can also use a directional antenna, such as a yagi, aimed at one specific sub-site. Remember that, where simulcast is involved, less antenna can work better that than a gain type antenna, even to the point of using a paperclip for an antenna.

Of course, all of these possible countermeasures are mainly effective when used at a fixed location. Out driving around in your vehicle, there's little you can do that will help. My other 436HP struggles when out in my SUV, so I generally carry my SDS100, not a 436HP.
 

kmartin

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I've been listening to the blue highlighted TGs on the NTIRN in the database or nodes. I have noticed improvement in the quality of how they sound. Before it was very hard to follow a conversation. Good job to whomever is providing these.
 

IAmSixNine

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That was the issue i had with my set up as well. So in the beginning i had 3 RTL SDR v3 dongles set up to monitor the new dallas site 3-1 (700mhz) and i was getting a lot of garbled transmissions. I also tested on a BK KNG2-P800, SDS100 and Unication G4. I got some very odd mixed results The SDS100 had excellent decoding while the KNG2 and G4 had intermittent audio cut out, almost like a funky AGC setting. The transmissions were clear (no garbling) but they would just cut out or go to very low audio and come right back up. The RTL SDR dongles had a lot of garbled transmissions.

BUT if i set stuff up to monitor on the Dallas 3-2 site (800mhz) all the equipment now functions properly. So why the RTL SDR and KNG2 and G4 didnt like the 3-1 set up is an odd ball issue i cant figure out. About once a month i re-test to see if its any better and this weekend is my next date to test the dongles on site 3-1.
Also if you are using RTL SDR with something like trunk recorder i highly recommend RDIO Scanner software. Been using it a few months and i really like it. Definitely helps me monitor stuff while at work and/or out of range.
 
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