MDT's

[DSYCUTTER]

Im trying to understand how these units work. If I were to get my hands on any of the variety offered and set it up to run through a scanner can i get it to receive the data. I should mention I am aware that it has to go through a discriminator output. any info would be greatly appreciated.

 

[SAR923]

Short answer is no. They are now commonly referred to as MDC's (Mobile Data Computers). There are a number of different standards fro MDC's sp having any one of them, or even several, wouldn't mean you had the right one for your area. They also have affiliate with the system used before the will receive anything. If you could receive anything, all the reaffic is encrypted so you'd need the correct key, which changes frequently, before you could read anything. If you were able to get the right MDC and jump through all the other hoops, you'd also be violating federal and probably many state laws about intercepting encrypted communications. All this means a quick trip to the hoosegow so finding another project would be a wise idea.

 

[INDY72]

AzScanner was working on a MDS project, but have not heard anything new from that in a while.

 

[Steve2003]

Most agencies use gprs and other cell phone companies for their data. I know that here in Colorado, Douglas County uses AT&T wireless for their MDCs. It is illegal to monitor any traffic on the cell band, so you are pretty much sol.

 

[richster]

Up here in Canada the MDT (mobile data terminals) use the 1.9Ghz cellular band as well. It's not illegal to monitor this band up here, but alot of good that does because all traffic in that band is all digitally encrypted. I think it's CDMA encryption, I'm not sure.

Regards,
Richster.

 

[INDY72]

MDS's use anything from VHF Hi, thru Sat Coms, and most are digital, with some encrypted. The problem is that for most of them to work as a data scanner, they have to affiliate with the network they are on. In this regard, they are as useless as trying to take a XTS5000 on a Motorola ASTRO-25 TRS as just a scanner,.... its not gonna happen. The same problems go with trying to get a sattelite radio, and using it as a scanner, it must affilliate with the sat net being used for a particular system's uplink/downlink, and thats the only way that it can access the talkgroups.

 

[AZScanner]

AzScanner was working on a MDS project, but have not heard anything new from that in a while.

Well I guess it's time for an update then...

Sorry but the MDT's I purchased fro this purpose are DOA, so I'm still at square one. I did manage to write a simple program to accept sound card input and slice it into 4 levels for the purposes of reassembling a bit stream but so far have not had any luck getting a recognizable RD/Lap frame sync or symbol sync , so I'm doing something wrong obviously. I play with it a little each day when I'm bored, but nothing new to report yet.

I'll definitely let everyone know if I get something working.

-AZ

 

[DSYCUTTER]

I appreciate all the info. Basically I was trying to set it up so that i could monitor the local power companies system. I am fully aware that monitoring a law enforcement system is a no no because of the fact they run DLs and have access to NCIC and ACS. So im not looking to break any laws. I just thought it'd be kinda neat to montior the power company, being that im an electrician in the area. I'd have a heads up when there were pwoer outages. Heck I'd even be able to know if those linemen were coming to power up my services that im waiting for.

But if it's truly a lost cause, I'll find some other project to get into.

sean

 

[Stephen]

In my city we use an 800mhz frequency for CAD and such and ATT for internet and out side communications.

 

[hcsd35-32]

At the agency where I work, we have never had MDTs. But, now thanks to the new Statewide system (Indiana Project Hoosier SAFE-T), we are due to get them soon. They will work on the 800MHz band that the system is on.