Scanners and MDC - That AWFUL Squawk...
- Thread starter rescue161
- Start date
- Status
n2nov
Active Member
You mean like the databurst noise that some local hams from Brooklyn have when they buy a Moto radio on eBay and use it on the ham channels? Yeah, real annoying!
Bentley
Member
I know, wrong forum....BUT, I see it in n2nov's signature....what the heck does 73 mean?? I see it all over the place here.
As I scanner hobbyist, I found the MDC and G-Star signalling noise to be a nuisance.
As a fire chief, I'm glad it's there. We know who is talking and we know who is in trouble. So that little irritation is okay with me.
Having said all that, we use MDC stuff as do the local police folks. I rarely hear it on my scanner. I suspect that when the MDC signalling goes out, it doesn't include PL tones, so my audio doesn't open up, or perhaps the repeaters are not repeating it.
As a fire chief, I'm glad it's there. We know who is talking and we know who is in trouble. So that little irritation is okay with me.
Having said all that, we use MDC stuff as do the local police folks. I rarely hear it on my scanner. I suspect that when the MDC signalling goes out, it doesn't include PL tones, so my audio doesn't open up, or perhaps the repeaters are not repeating it.
MDC can transmit the characters 0 thru 9 and the letters A, B, C, D or E. It actually uses hex numbers from 0001 thru DEEE, which allows up to 57070 different ID's. I don't know why the letter "F" is not allowed.
Some manufacturers of MDC decoders allow you to create a Call List that allows an alias to be displayed instead of the actual ID transmitted. For example the number 0410 would be transmitted but the display could read "Sgt. Smith" instead.
Therea re several ways a scannist can decode MDC. The WinMDC program already noted would work, as would outboard decoders. Cimarron makes a line of decoders that work well with record level or discriminator audio. I also occasionally see at hamfests or eBay various Motorola desk sets that decode MDC.
My agency's network uses 3 digit numbers for star numbers and each officer has an assigned portable, so they ID with his or her star number (0410, 0592 etc.). Mobiles have the letter "C" in the first position, to ID it as a car. Therefore my portable shows up as 0410, my car as C410. Since, as the local radio guy, I have more than 1 portable, I have other radios that ID as 410A, 410B etc.
Our local Fire dispatch center uses a different system. Rigs ID with the first 2 characters as the station assigned, the third as the type unit (xx1x are engines, xx2x are ambulances etc.) and the last character id's which radio on the rig. 2110 is the main radio from Engine 21, 2111 is the rear radio, 2112, 2113, 2114 are portables from the same engine.
If you can decode MDC it only takes a short while to figure out the numbering system.
Some repeater systems have a delay that keeps the MDC from being retransmitted most of the time. I have that "feature" disabled on my repeaters so that my mobiles and portables can decode the MDC (and I can watch it from home when I am really bored!).
When we rebuilt our system and replaced our old GE Mastr2 repeaters (with GE-Star) with Motorola Quantars a couple years ago the guys complained for a couple days about the MDC squawks, but eventually got so used to it that they do not even notice it any more.
Some systems also are set up to deny access unless a valid MDC code is transmitted.
GE-Star is another popular format. I happen to have an old GE-Star decoder that I occasionally set up. I recovered it from a console that I deconstructed a few years back.
Some manufacturers of MDC decoders allow you to create a Call List that allows an alias to be displayed instead of the actual ID transmitted. For example the number 0410 would be transmitted but the display could read "Sgt. Smith" instead.
Therea re several ways a scannist can decode MDC. The WinMDC program already noted would work, as would outboard decoders. Cimarron makes a line of decoders that work well with record level or discriminator audio. I also occasionally see at hamfests or eBay various Motorola desk sets that decode MDC.
My agency's network uses 3 digit numbers for star numbers and each officer has an assigned portable, so they ID with his or her star number (0410, 0592 etc.). Mobiles have the letter "C" in the first position, to ID it as a car. Therefore my portable shows up as 0410, my car as C410. Since, as the local radio guy, I have more than 1 portable, I have other radios that ID as 410A, 410B etc.
Our local Fire dispatch center uses a different system. Rigs ID with the first 2 characters as the station assigned, the third as the type unit (xx1x are engines, xx2x are ambulances etc.) and the last character id's which radio on the rig. 2110 is the main radio from Engine 21, 2111 is the rear radio, 2112, 2113, 2114 are portables from the same engine.
If you can decode MDC it only takes a short while to figure out the numbering system.
Some repeater systems have a delay that keeps the MDC from being retransmitted most of the time. I have that "feature" disabled on my repeaters so that my mobiles and portables can decode the MDC (and I can watch it from home when I am really bored!).
When we rebuilt our system and replaced our old GE Mastr2 repeaters (with GE-Star) with Motorola Quantars a couple years ago the guys complained for a couple days about the MDC squawks, but eventually got so used to it that they do not even notice it any more.
Some systems also are set up to deny access unless a valid MDC code is transmitted.
GE-Star is another popular format. I happen to have an old GE-Star decoder that I occasionally set up. I recovered it from a console that I deconstructed a few years back.
N9JIG said:
That's what I'm talking about. You could enable DOS on their radios and they wouldn't even hear the burst anymore, just a single beep.
I'll make some sounds samples today and post them.
Well, as promised, here are two MP3s to compare. Sorry for the bad quality. The scanner file (Without DOS) is VERY loud. I guess I can play with the volume settings to get them right, but traffic on this system on a Sunday is next to nothing.
I think the folks that say MDC is a sound that they like would change their minds if they ever listened on a Motorola radio with DOS enabled. It makes a WORLD of difference.
Let me know if you think I'm crazy ;-)
I think the folks that say MDC is a sound that they like would change their minds if they ever listened on a Motorola radio with DOS enabled. It makes a WORLD of difference.
Let me know if you think I'm crazy ;-)
Here is another scanner file that is a little easier on the ears. I didn't catch it in time to get the Motorola radio recorded. I guess I should be doing this on a Friday night.
R
Rayjk110
Guest
"I don't know why the letter "F" is not allowed."
Because "F" is involved in MDC "All Calls", IE if you were to page "FFFF", all radios with MDC enabled, presuming that MDC RX Alerts ara enabled in CPS/RSS, they would all go off on that frequency. One of my AstroSaber's can do it, but that's the only radio I have that can from the front panel.
Because "F" is involved in MDC "All Calls", IE if you were to page "FFFF", all radios with MDC enabled, presuming that MDC RX Alerts ara enabled in CPS/RSS, they would all go off on that frequency. One of my AstroSaber's can do it, but that's the only radio I have that can from the front panel.
n2nov
Active Member
73 is morse code/telegraph shorthand for "best wishes". That's why is is not 73's, because it would translate to "best wishes-es"! On a connected note, if you've ever heard Ian McFarland of Radio Canada International fame on shortwave in the 80's and 90's, you would have heard him end the program with "73 and 88 to the ladies". 88 means "hugs and kisses".
clyde
Member
I also have same problem as MB with my 780. Cant seem to get program to work. Any thoughts? Tanks
Rayjk110 said:
I did not know that, thanks!
Multiple site programming for conventional systems.
It appears that only trunked systems can be programmed with multiple sites. The Kentucky State Police uses a conventional P25 UHF system. Each post has its own frequencies and several transmitter sitates within the post area. The multiple site feature would work well for this, but I can't seem to figure out how to do multiple sites for a non-trunking system.
Does anyone have any suggestions (other than building one system for each post)?
Thanks!
It appears that only trunked systems can be programmed with multiple sites. The Kentucky State Police uses a conventional P25 UHF system. Each post has its own frequencies and several transmitter sitates within the post area. The multiple site feature would work well for this, but I can't seem to figure out how to do multiple sites for a non-trunking system.
Does anyone have any suggestions (other than building one system for each post)?
Thanks!
ofd8001 said:
This is where NAC would come in handy if they are using it. NAC is like PL/DPL in digital land.
ofd8001 said:
Just put each of the freqs in the same system. If you are in range of the repeater you will hear the traffic. Be sure to program the System as conventional.
Hello,
Thanks for the thread. I tried the program and found that my local police use MDC1200. I have been listening to the data burst for years. It appears the id is the car number for mobiles and higher numbers for portables. Very interesting to watch although the program does not decode all the MDC1200 bursts.
73 Eric
Thanks for the thread. I tried the program and found that my local police use MDC1200. I have been listening to the data burst for years. It appears the id is the car number for mobiles and higher numbers for portables. Very interesting to watch although the program does not decode all the MDC1200 bursts.
73 Eric
I've tried this program on 2 different computers today (one running XP, the other Win2k) with no results what so ever. Doesn't do a thing. Out of curiosity I downloaded WinCTCSS from the same site and it works great. Anyone have any suggestions as to why it may not be working? I've tried both line in and microphone, and I can hear the scanner audio just fine on my speakers. Any suggestions welcomed! Oh... and I have the scanner listening to multiple agencies with the MDC 'sqwak' at the end of their transmissions, so it's not just one agency I'm trying to decode. Anyone know if there are any other MDC1200 software decoders out there?
Forts said:
Its working fine for me with a 246T and a 780XLT. You may have to play with your volume, I had to make some adjustments on my volume on the Mic input and the scanner till I could decode. I have it decoding my local PDs IDs just fine. You have to play with your settings if the transmitting station is too loud I've noticed it wont decode properly.
73
Thanks! I'll give that a try. I'm using a 780 as well. Maybe I'll try my 246 too.
- Status
Similar threads
XTL/XTS5000
MDC Select Calling Help
