Sound Card MDT decoding!!!!

Sound Card MDT decoding!!!!

Post by Jac » Tue, 24 Nov 1998 04:00:00

If you have not yet tried it, do it now!
http://www.jps.net/gordone/mdt/

That's right! You can now decode MDT with your soundcard
+ an awesome windows interface.

-
UTC-5
26.1972800/-080.1707083  
Fort Lauderdale, FL
http://www.geocities.com/SiliconValley/Network/8916/

 
 
 

Sound Card MDT decoding!!!!

Post by Ramjet » Tue, 24 Nov 1998 04:00:00


This is a great program. I downloaded it, plugged in my scanner with the
discriminator tapped, plugged in the Alerts freq. of 857.7375 and the screen
filled with info.

>If you have not yet tried it, do it now!
>http://www.jps.net/gordone/mdt/

>That's right! You can now decode MDT with your soundcard
>+ an awesome windows interface.

>-
>UTC-5
>26.1972800/-080.1707083
>Fort Lauderdale, FL
>http://www.geocities.com/SiliconValley/Network/8916/

 
 
 

Sound Card MDT decoding!!!!

Post by Phil Smalle » Tue, 24 Nov 1998 04:00:00


>If you have not yet tried it, do it now!
>http://www.jps.net/gordone/mdt/

>That's right! You can now decode MDT with your soundcard
>+ an awesome windows interface.

I too have tried this program, last Friday. I really like the interface, and
the ability to decode directly from the soundcard is very cool, but alas,
the program sat there on my screen looking at me, and doing nothing. I tried
the Mic input, the Line in input, every possible setting, searched for

lump. (gloom)

So, my question is:

To those who got it working, what kind of soundcard do you have? Perhaps
it's time to upgrade...

What settings worked for you? Maybe I'm missing one?

What frequencies do you monitor (perhaps the ones in my area are using the
cursed 19.2 baud rate, although it *sounds* like MDC-4800 to me....) I know
there are some nationwide ones out there, anybody have those handy?

If you live in the Phoenix area, then this information is even more relevant
for me. If you live in Phoenix and use a BC895 for this then let me buy you
lunch if you get this thing to work!

I know I've got the discriminator tap right because I can turn on my PC
speakers and hear the audio coming thru clearly. The tap was installed per
the instructions provided by Greg Knox. (Have you gotten this to work Greg?)
I can also record the sound with Windows Sound Recorder, and play it back,
no problem, nice and clear. I receive a strong signal (4 bars on the BC895's
display), so I know that's not it. I'm installing it on a laptop today, and
will try it tonight since it's built in sound card is newer than the one in
my PC. (The laptop was to be the desired destination for this thing anyway,
I think you can see where this is going...).

I mean it guys, I've tried everything under the sun. I read, re-read, and
read again, the FAQ, the discriminator tap instructions, the Bible (hey, you
never know), everything. I did everything by the numbers, but no data (not
even in the Raw Data window! ACK!) I drew the line at diving into the source
code, but (sigh) that's next.

Bottom line: If you got this thing to do more than sit there, PLEASE
respond! I too want to revel in the glory of tasting the "forbidden fruit"
that is MDT data! ;-)



Thank you , thank you, THANK YOU in advance for any help,
-Phil

 
 
 

Sound Card MDT decoding!!!!

Post by Greg Kn » Tue, 24 Nov 1998 04:00:00



The problem is probably that the system you want to monitor is using a
different protocol than that for which the software was developed. There
are a few protocols and several different manufacturers.

Greg Knox


>>If you have not yet tried it, do it now!
>>http://www.jps.net/gordone/mdt/

>>That's right! You can now decode MDT with your soundcard
>>+ an awesome windows interface.

>I too have tried this program, last Friday. I really like the interface, and
>the ability to decode directly from the soundcard is very cool, but alas,
>the program sat there on my screen looking at me, and doing nothing. I tried
>the Mic input, the Line in input, every possible setting, searched for

>lump. (gloom)

>So, my question is:

>To those who got it working, what kind of soundcard do you have? Perhaps
>it's time to upgrade...

>What settings worked for you? Maybe I'm missing one?

>What frequencies do you monitor (perhaps the ones in my area are using the
>cursed 19.2 baud rate, although it *sounds* like MDC-4800 to me....) I know
>there are some nationwide ones out there, anybody have those handy?

>If you live in the Phoenix area, then this information is even more relevant
>for me. If you live in Phoenix and use a BC895 for this then let me buy you
>lunch if you get this thing to work!

>I know I've got the discriminator tap right because I can turn on my PC
>speakers and hear the audio coming thru clearly. The tap was installed per
>the instructions provided by Greg Knox. (Have you gotten this to work Greg?)
>I can also record the sound with Windows Sound Recorder, and play it back,
>no problem, nice and clear. I receive a strong signal (4 bars on the BC895's
>display), so I know that's not it. I'm installing it on a laptop today, and
>will try it tonight since it's built in sound card is newer than the one in
>my PC. (The laptop was to be the desired destination for this thing anyway,
>I think you can see where this is going...).

>I mean it guys, I've tried everything under the sun. I read, re-read, and
>read again, the FAQ, the discriminator tap instructions, the Bible (hey, you
>never know), everything. I did everything by the numbers, but no data (not
>even in the Raw Data window! ACK!) I drew the line at diving into the source
>code, but (sigh) that's next.

>Bottom line: If you got this thing to do more than sit there, PLEASE
>respond! I too want to revel in the glory of tasting the "forbidden fruit"
>that is MDT data! ;-)



>Thank you , thank you, THANK YOU in advance for any help,
>-Phil

 
 
 

Sound Card MDT decoding!!!!

Post by Phil Smalle » Tue, 24 Nov 1998 04:00:00


>The problem is probably that the system you want to monitor is using a
>different protocol than that for which the software was developed. There
>are a few protocols and several different manufacturers.

>Greg Knox

Ohhhhh I want to believe that, but the Motorola emblem on Phoenix PD & FD's
MDTs is casting some doubts.... however they *are* newer models and may use
a different protocol. (That'd just figure, too, dammit..)

I went to the home page for this thing and listened to the .wav sample of
MDC-4800 and I swear it sounds identical to what I'm trying to decode. But
you may be right. I just wish I knew a local frequency that *is* MDC-4800 so
I can be sure.

Anyone in Phoenix have the answers?

-Phil

 
 
 

Sound Card MDT decoding!!!!

Post by Jac » Tue, 24 Nov 1998 04:00:00

On Mon, 23 Nov 1998 12:20:49 -0700, "Phil Smalley"


>Ohhhhh I want to believe that, but the Motorola emblem on Phoenix PD & FD's
>MDTs is casting some doubts.... however they *are* newer models and may use
>a different protocol. (That'd just figure, too, dammit..)

Their is a 19.2k version.

Quote:>I went to the home page for this thing and listened to the .wav sample of
>MDC-4800 and I swear it sounds identical to what I'm trying to decode. But
>you may be right. I just wish I knew a local frequency that *is* MDC-4800 so
>I can be sure.

I noticed that the input level needs to be set to 20% on my awe64
soundcard for the decoder to work. I also noticed their is an invert
setting under options, might make it start working. If you have the
dos version and a slicer, if you just scan the band's you should
eventually find one. You will know for sure because something will
start happening immediately if you hit one. Might be a row of
asterisks if it needs to be inverted. With the soundcard version if
their is no activity it will appear that nothing is happening.

-
UTC-5
26.1972800/-080.1707083  
Fort Lauderdale, FL
http://www.geocities.com/SiliconValley/Network/8916/

 
 
 

Sound Card MDT decoding!!!!

Post by Phil Smalle » Tue, 24 Nov 1998 04:00:00


>Their is a 19.2k version.

Yeah, and I bet that's what they use too - those bastards! ;-)

Quote:>I noticed that the input level needs to be set to 20% on my awe64
>soundcard for the decoder to work. I also noticed their is an invert
>setting under options, might make it start working. If you have the
>dos version and a slicer, if you just scan the band's you should
>eventually find one. You will know for sure because something will
>start happening immediately if you hit one. Might be a row of
>asterisks if it needs to be inverted. With the soundcard version if
>their is no activity it will appear that nothing is happening.

Well I know I'm getting activity, I even recorded the sounds I was
receiving, and watched them in the meter in Sound Recorder. But the protocol
might be wrong.

I did some digging and found the frequency for the Nationwide Ardis Network
and I can receive it here in Phoenix. (For anyone interested, the frequency
is 855.8375) so I will try this one and see.

Thanks,
-Phil

 
 
 

Sound Card MDT decoding!!!!

Post by Jac » Wed, 25 Nov 1998 04:00:00

On Mon, 23 Nov 1998 16:48:42 -0700, "Phil Smalley"


>I did some digging and found the frequency for the Nationwide Ardis Network
>and I can receive it here in Phoenix. (For anyone interested, the frequency
>is 855.8375) so I will try this one and see.

Ardis! I forgot all about that one! Most of the traffic I have
received there in the past was encrypted, but it would make a good
test bed for most everyone in the USA!
-
UTC-5
26.1972800/-080.1707083  
Fort Lauderdale, FL
http://www.geocities.com/SiliconValley/Network/8916/
 
 
 

Sound Card MDT decoding!!!!

Post by SSchreibe » Wed, 25 Nov 1998 04:00:00


>>If you have not yet tried it, do it now!
>>http://www.jps.net/gordone/mdt/

>>That's right! You can now decode MDT with your soundcard
>>+ an awesome windows interface.

Is MDT only in the USA to hear or can I decode this also here in
Europe, Germany?  Any 1 have freqs for me?
Thanks, Stephan
 
 
 

Sound Card MDT decoding!!!!

Post by Bob » Wed, 25 Nov 1998 04:00:00

Phil,

Motorola has at least 4 actively used MDT over the air protocols, and a couple
of retired ones.

MDC600, No Longer Used for MDT

MDC1200, No Longer Used for MDT, but still around used primarily for call
alerting and signalling on convetional.

MDC4800, Legacy Data Systems, Not a production protocol except for system add
ons to legacy systems.

MMP4800, Legacy Data Systems (old MDI Protocol),Not a production protocol except
for system add ons to legacy systems.

RD-LAP  9.6

RD-LAP 19.2

Most of these PC based decoders are for MDC4800.  To date, it is the only known
Motorola MDT protocol which has been "cracked/hacked".

It should also be noted, that even if you decode the data stream, what you will
see on the screen is mostly header and other FEC info, with an occasional glips
of use text.  One needs to remember that MDC is a 1/2 rate code, which means
that 50% of every message is FEC.  You may be able to decode the  data stream,
but don't expect to see crystal clear messages popping up on your PC.  It's just
not going to happen.

Good Luck!



> >The problem is probably that the system you want to monitor is using a
> >different protocol than that for which the software was developed. There
> >are a few protocols and several different manufacturers.

> >Greg Knox

> Ohhhhh I want to believe that, but the Motorola emblem on Phoenix PD & FD's
> MDTs is casting some doubts.... however they *are* newer models and may use
> a different protocol. (That'd just figure, too, dammit..)

> I went to the home page for this thing and listened to the .wav sample of
> MDC-4800 and I swear it sounds identical to what I'm trying to decode. But
> you may be right. I just wish I knew a local frequency that *is* MDC-4800 so
> I can be sure.

> Anyone in Phoenix have the answers?

> -Phil

 
 
 

Sound Card MDT decoding!!!!

Post by Gordon Edwar » Wed, 25 Nov 1998 04:00:00



>>>If you have not yet tried it, do it now!
>>>http://www.jps.net/gordone/mdt/

>>>That's right! You can now decode MDT with your soundcard
>>>+ an awesome windows interface.

>Is MDT only in the USA to hear or can I decode this also here in
>Europe, Germany?  Any 1 have freqs for me?
>Thanks, Stephan

Some people are using it to decode MDT traffic in Denmark and Australia.

Gordon