200mhz?

[CDS-INC]

I want to use a Decoder software to decode MPT1327 systems,
What kind of scanner or radio will i need to get to do this?
and will i be able to locate/listen to the talkgroups?

Please go slow with me, i am new to MPT1327

[loumaag]

Originally Posted by CDS-INC

I want to use a Decoder software to decode MPT1327 systems,
What kind of scanner or radio will i need to get to do this?
and will i be able to locate/listen to the talkgroups?

Please go slow with me, i am new to MPT1327

When you say Decoder software, I assume you mean something like UniTrunker or another software specifically designed for MPT-1327 systems. If this is the case, any radio that covers the spectrum and supplies the audio will do.

As for tracking the "talkgroups", that is a function of having another "steerable" radio used with decoder software that can steer it. Most of these questions can be answered by searching through the Trunking Decoder forum. You might also look through the MPT-1327 forum as well as the RR Wiki.

Edit: To those of you who keep reporting this thread, take a good look and you will notice that it really does belong in this forum; at least I think it does or I wouldn't have replied here.

[jb872033]

So you dont have to have a computer controlled scanner? i thought you had to have a computer computer controlled scanner to even hear these systems...

JB

[wayne_h]

Moved.

[CDS-INC]

ok, i have a Tait 200mhz mobile radio, can i program the control channels in this radio and do the Tap and use the software to listen to voice on this MPT 1327 system?.
Im really confused about what i need to do?

[citylink_uk]

I find the best way is to hook a scanner up to one of the free decoding programs such as Trunkview (http://www.linato.net/trunkview/.)

No disc tap is required; all you require is a scanner that is computer controllable (most modern ones are), a lead from PC to Scanner and an audio cable from Scanner to PC's sound card Input or Mic.

Enter a few settings and it will be decoding.

Not sure about using the radio, I think there are multiple system numbers you would require to get it tracking. The only way to decode is via static PC monitoring at the moment as no scanner manufactures have included the open protocol in their scanners yet.

Of course you could always just enter in the voice frequencies and press scan, but you wouldn't know who’s talking.

[CDS-INC]

so, with this software, you can track the Talkgroups and listen to them?

[citylink_uk]

Originally Posted by CDS-INC

so, with this software, you can track the Talkgroups and listen to them?

Yes you can.

You can assign alpha tags to each talkgroup and even filter out talkgroups you don't want to listen too. It will also log traffic for you and allow you to store talkgroups and ID's, if only it could be implemented into a handheld!........

[CDS-INC]

So what kind of Scanner or Receiver would i need to track 200mhz?

[Jay911]

I believe the only place where the 200MHz MPT systems are in place are in the European Union, which means you would need an EU-market scanner to be able to tune that frequency band.

Almost every MPT system I've been exposed to in North America lies squarely between 422.0 and 424.9875MHz.

Could you give us a hint where you are and what system(s) specifically you're looking to listen to?

[jb872033]

I am interested in listening to http://www.radioreference.com/apps/db/?sid=5085 which is a public utility system on ~217 mhz ... i know i am not the original poster in the forum and in no way am attempting to "hijack" it, but i think our questions are one in the same...I have a non computer controllable scanner (pro-97) and am interested in listening to this system...can i? i know tgids wont be possible, but i would like to hear voice for this system. thanks for any input....

JB

[Jay911]

Ok, well, evidently there are systems out there I don't know about.

If you only have the one scanner, you won't be able to follow audio conversations with something like Trunkview. However, you will be able to figure out talkgroup and radio IDs.

All you have to do for MPT1327 is take a cable and patch it from the headphone jack on your scanner to the line-in jack on your sound card. Make sure your system is set up to use the sound card for "recording" (I don't have a Windows machine handy, but if you go Start>Control Panel>Sounds & Audio Devices>Volume Control, I think you may be 90% of the way there). Run Trunkview and it should start receiving data almost right away.

Determining the channel number(s) will be your next task. Much like UHF/VHF Motorola trunking, MPT systems have a base, step, and offset setting. The only way to know what setting to use is to start running the Trunkview program and get some data, then figure out what you have. Having a second scanner you can play with while Trunkview is running is especially helpful here. For example, if you see a voice call (known as a Go To Channel on an MPT system) come up, scan (with your non-Trunkview occupied scanner) through the other frequencies on that site/tower. Once you hear a voice, you're (hopefully, if the system isn't too busy) on the right channel.

Now, the frequency shown by the channel number and the one you see on your second scanner are almost certainly going to be not the same. For example, Trunkview might say the GTC (Go To Channel) command should move to channel 105, or frequency 187.2250, when you see on your other scanner that the actual voice channel is 217.1250. That would mean that you are exactly 29.9 MHz off (too low) in your settings. If you're lucky, Trunkview will catch at least one other channel while you're doing all this. If not another voice channel, then the control channel - which may come in the form of a Clear Down message. Let's say it says "Clear-down - return to control channel 135 (187.6000)". In this case you'd be lucky because 187.6 is exactly 29.9 less than 217.5 - the control channel of the site I'm using as an example (from your referenced public utility system). You'd then know that channel 135 is actually 217.5, channel 105 is actually 217.1250, and thus you have 12.5 kHz spacing (step) - because the difference (0.375) between the two channels goes into 0.0125 exactly 30 times.

Now you can figure out the base with a little bit more simple math. If 217.5 is channel 135, and the step is 12.5 kHz (0.0125 MHz), then channel 1 would be 217.5 minus (134 times 0.0125), or 215.825. So, with base 215.825, offset 0, and step 12.5 kHz, you should then get the right frequencies showing up on your Trunkview display. And now if you have a computer-controllable scanner, Trunkview will tune it to the proper frequency on every Go To Channel call, and you will hear calls on both "talkgroups" and "private calls".

I know that's a little lengthy, but it'll get you where you want to be. If you need more help, this thread is the place to come - citylink has a ton of info and spends a lot of time on these systems, I think, more than I did when I had them available in my area.

[jb872033]

Thank you for your weatlth of information, and once again proving that i am a mere neophyte in the ranks here...it is much appreciated, i plan on figuring this all out this weekend, and once again am greatful for the RR forums for brining people with so much knowledge into one place...

JB

[citylink_uk]

Originally Posted by Jay911

If you only have the one scanner, you won't be able to follow audio conversations with something like Trunkview. However, you will be able to figure out talkgroup and radio IDs.

Hi,

I use a Uniden UBC3500XLT which runs into Trunkview with the serial connector and a 3.5mm audio cable from the Headphone jack on the scanner, to the 'Line In' or Microphone socket on the PC.

You can run the tracking perfectly on just one scanner. Mine monitors the control channel and decodes all of the system info, but when a voice call is passed it tunes the scanner to that channel so I can monitor the conversation. When the 'clear down' message is picked up by Trunkview and the conversations over, it retunes the scanner back to the control channel to continue logging.

I find this works great for me. You can set it up with two scanners so one constantly decodes data whilst the other tunes to voice channels but I havn't found the need to do that yet.

Yes, MPT is the only trunking protocol over here and I currently have over 30 control channels in range from 86mhz to 457mhz.

[Jay911]

Originally Posted by citylink_uk

You can run the tracking perfectly on just one scanner.

The OP (or the person I was replying to) stated he has a PRO-97 - a non-computer-controllable scanner.

No matter how hard you try, that combination won't get you any tracking, using Trunkview or any other program.

[CDS-INC]

can 200mhz MPT 1327 Systems be tracked conventionally?
I have a Tait Radio that is 200mhz and if i just put the frequencies for this system in conventional mode, will i be able to listen to the system without knowing the talkgroups?
I dont really care about the talk groups at this point because on this particular system there are only 3 for right now,
So i am wondering if MPT 1327 can be monitored in conventional mode?

[Jay911]

Yes MPT1327 can be monitored conventionally.

I was in a boat similar to yours for several years here in my area - the neighboring FD employed an MPT system with only 4 talkgroups. Our crews still wanted to be able to hear them, so we had their freqs in our radios in receive-only mode, and just locked out the control channel whenever it rotated.

[morfis]

Originally Posted by citylink_uk

Hi,
Yes, MPT is the only trunking protocol over here .....

Off topic regards the original post but how can you say this Rich? Customs are using several different trunked protocols, you've replied elsewhere about TETRA, SPTA are using several protocols including EDACS, Staffs Fire & Rescue are still using their Smartnet system

[citylink_uk]

Originally Posted by morfis

Off topic regards the original post but how can you say this Rich? Customs are using several different trunked protocols, you've replied elsewhere about TETRA, SPTA are using several protocols including EDACS, Staffs Fire & Rescue are still using their Smartnet system

Hi, I agree but I was trying to make a general statement about the commercial sector.

There's the two site SPTA Army EDACS system, two P25 ENC TRS's for USAF bases and one Motorola SmartZone system, the latter in its final two years of operation. That's it. For the whole of the UK.

Customs were using P25 ENC in Conv/Repeater modes non trunked, however they are upgrading to the Airwave TETRA network.

Yes there's TETRA in use; but apart from one commercial user and an airport, it's Public Safety only.

There's hundreds and hundreds of MPT1327 systems in use so these special cases are exceptions.