MDC Signal Sound

[Squad5]

How do I change the sound of the MDC sound that is transmitted?

[jmr061]

How do I change the sound of the MDC sound that is transmitted?

Um what are you looking to change it to?

Jason

[N6LAU]

You could always enable "preamble with pre-time" which adds extra data noise (almost similar to a generic cell phone ringer) during the pre-time before the actual ID is sent. There is also "preamble bit sync" which is essentially the same thing with the length of the extra noise being adjustable independently of the pre-time via a numeric value. The higher the value the longer (aka more obnoxious) the extra noise becomes.

If you're dealing with a Saber you could opt to use MDC-600 which has a somewhat different sound than 1200, almost similar to GE Star signaling.

I suppose, technically, changing the ID number of the MDC message being transmitted would change the sound although whether it would be noticeable to the human ear is another story.

[Squad5]

I've just heard different signaling sounds one our PD band, other FD bands Etc. Just wondering how to change it

[N6LAU]

Chances are you're hearing, MDC1200, GE Star, or maybe even MODAT. On the LA County Sherrifs TAC frequencies here in SoCal you usually hear a mix of MDC1200 or GE Star. The majority of other agencies around here use MDC1200 for they're signalling if any at all. There are several Motorola radios that offer MDC1200 AND GE Star as a selectable signalling type. Fewer are Motorola radios that offer MODAT. What radio are you looking to change this on or were you merely curious on how this is done?

[Squad5]

Its on a xts 5k. Pretty sure it is MDC but not too sure lol

[N6LAU]

I think you can only do MDC1200 with a 5k unless you have another signalling type in your flash options like GE Star.

Joe

[MT2000 man]

What's the flashcode of your 5K ? As was said, it all depends on your flashcode on what signaling options your radio can do, however, most of the 5000's I've seen can at least do MDC signaling. Others MODAT, GE Star, etc. are all flash options. Hell, I'm not even sure you can even flash an XTS5000 for MODAT, (I know you can on the Astro Saber line, XTS3000, etc., so I would assume you can for the newer 5000's as well).


If you are looking to MUTE the incoming MDC "squawk" on the reciving audio, simply activate DOS (Data Operated Squelch) in the MDC Signaling menu in the CPS.

[d119]

Hell, I'm not even sure you can even flash an XTS5000 for MODAT.

Nope, no MODAT in anything past the XTS 3000. I'm fairly sure the only reason MODAT was in the ASTRO Saber was because LAPD required it before their digital transition, and it likely ended up in the XTS 3000 because it and the ASTRO Saber are so very closely related.

It's likely that because the radio operating system and firmware are vastly different in the ASTRO25 series vice the original ASTRO series, and the fact the ASTRO25 series came out after the LAPD digital conversion, it was never carried over to the ASTRO25 series.

I'm not entirely convinced LAPD was even decoding it in the last few years of their analog system once they made the switch to Centracom Gold Elite dispatch consoles. I think the consoles they were using to decode MODAT were a special product engineered and built by Rockwell. Sure wish I had more details on it.

For that matter, I've never seen an ASTRO25 radio that offered GE-Star signaling. But that should not be taken as an implication that they can't support it.

[Squad5]

Flashcode is : 540008-101C86-7

I did have a 3k before this 5k, and the original owner had it make a sound (can't really describe it) when keying up instead of the normal just short tone BEEP my 5k does.

As for the MDC after a transmission, I have heard different ones on different channels. Mostly some the same on both channels. Just wondering how to change it

[Squad5]

Did a bit more research on this and found a good website : http://www.w2sjw.com/radio_sounds.html

The normal one Mine does now is the first one, But I the other one I hear is the echo one. Just wondering how to change it to that if I ever need to in the future.

Also, Is MODAT is what my 3k used before keying up on the VTach channels. But I see that they do not have that after the 3k now

[bezking]

You can't turn on the echo - some radios will transmit the end of the MDC sidetone over the air because the transmitter is turned on just a bit too early, but it's an accident and a bug in the firmware. It's not supposed to happen so there's really no way to replicate it.

[MT2000 man]

Hell, I'm not even sure you can even flash an XTS5000 for MODAT.

Nope, no MODAT in anything past the XTS 3000. I'm fairly sure the only reason MODAT was in the ASTRO Saber was because LAPD required it before their digital transition, and it likely ended up in the XTS 3000 because it and the ASTRO Saber are so very closely related.

It's likely that because the radio operating system and firmware are vastly different in the ASTRO25 series vice the original ASTRO series, and the fact the ASTRO25 series came out after the LAPD digital conversion, it was never carried over to the ASTRO25 series.

I'm not entirely convinced LAPD was even decoding it in the last few years of their analog system once they made the switch to Centracom Gold Elite dispatch consoles. I think the consoles they were using to decode MODAT were a special product engineered and built by Rockwell. Sure wish I had more details on it.

For that matter, I've never seen an ASTRO25 radio that offered GE-Star signaling. But that should not be taken as an implication that they can't support it.

Ahhh, good to know !

I would assume the LAPD now currently uses primarily XTS5000 radios, and ditched all of thier old Astro Sabers by now ?

Also, for the OP - yes, as was stated that MDC "echo" of the beep, is just the transmitter getting the last half of the PTT beep from the other transmitting radio. A lot of our cars do the same thing (person keys up the mic, MDC1200 noise emits, followed right after with a little "PTT beep". As was said, firmware issue. I just have all of my radios set for DOS, so it mutes the MDC noise (or at least a good part of it) all together.

[d119]

Ahhh, good to know !

I would assume the LAPD now currently uses primarily XTS5000 radios, and ditched all of thier old Astro Sabers by now ?

More or less. LAPD made a large purchase of XTL 5000 mobiles and XTS 5000 handhelds, and were decommissioning the ASTRO Saber portables by means of the drill press. (I know, I agree, and I don't want to hear about it).

There are still plenty of ASTRO Sabers being used by LAPD, but they are not long for this world.
They've also upgraded their dispatch centers from Motorola Centracom Gold Elite to Motorola MCC 7500 series consoles. No more rooms full of DIU's. And of course, no more audible signaling either since they went to digital. It's all embedded signaling now.

I wish I'd have had the sense to record a few days worth of LAPD radio traffic back when they were analog. There aren't really any good, long recordings from back in those days floating around the internet, other than the North Hollywood shoot out, which you can only listen to so many times. The analog T-band system was pretty cool. It was a very unique system with a very unique sound.

[MT2000 man]

Thanks for the info. !

I kinda figured the LAPD would eventually migrate over to the newer XTS5000's / XTL5000's.

Also good info. on the dispatch consoles as well. Being on the other side of the country, (that, and I hardly travel to LA anymore ) I haven't kept too up-to-date on what the LAPD was up to in the radio department in the last year or so.

[d119]

Thanks for the info. !

I kinda figured the LAPD would eventually migrate over to the newer XTS5000's / XTL5000's.

Also good info. on the dispatch consoles as well. Being on the other side of the country, (that, and I hardly travel to LA anymore ) I haven't kept too up-to-date on what the LAPD was up to in the radio department in the last year or so.

Yep. They are more or less a cookie-cutter ASTRO25 7.x Conventional system now, nothing special or custom like it used to be. Word on the street is that Motorola is not really into doing the whole SP thing anymore, so you will take what flavor cake they are serving and like it.