Can it be Done??

[Mikey]

Ok Guys, Here is what i'm trying to do, Can it be done?

I want to take a Radio and program a MDC Pre-key ID in it so every time that radio keys up it transmits the MDC ID String, Now on the other end i have a Mobile that i want to be Muted Audio Wise until it receives that MDC ID from the first radio at which time it will unmute the Audio and they can hear radio traffic. I would like this mobile radio to reset to a muted condition after X Number of seconds after carrier drops, but if i need to reset manually that is ok too. Can this be done?

[Mikey]

Can i use the MDC Repeater Access Function Possibly?

[thebigphish]

So you want essentially a SelCall done by MDC, and then auto mute on the recieving end? What kind of radios?

[Mikey]

Yes, i'm actually needing to use the MDC kinda like a Pl Tone. I'm Using CDM1250 and HT1250 Radio's. I new i could send out a MDC Select Call using a button programmed on the front, but i wasn't sure if i could do it using the Pre Key ID?

Mike

[wavetar]

No, the radio requires the Selcall to unmute...just because it's MDC doesn't mean PTT-ID is treated the same as a Selcall, it's an entirely different command.

[dbfd588]

string isn't even possible as a MDC ID is it? I think its letters A-E and 0-9.....Am I wrong?
And only 4 digits..

[Mikey]

So there is really no way of sending an MDC pre-key and getting a mobile to unmute just off that Pre-key ID.

[akardam]

Probably about the closest you're going to get is with the Auto Sel Call feature.

[wavetar]

So there is really no way of sending an MDC pre-key and getting a mobile to unmute just off that Pre-key ID.

As I said above, no. You might as well ask the radio to respond with a 'radio check', or react like you sent a 'radio disable'. Different MDC functions, plain & simple.

[WB6DGN]

There is a stand-alone MDC decoder that I used to use at the shop where I worked that will decode both MDC and emergency codes and display them on an LED display. We used to use it to check MDC function on repaired radios (what a waste!) I never had a reason to check if there were relay contacts available for such a function or not but by the looks of it that should be easy to add if they're not already there. I've been away from there too long to remember the model number of that thing but it does exist and I'm pretty sure it would do what you want. It would require a manual reset, however. By the way, I'd like to find one of those for a use I have as well.
Tom DGN

[Mikey]

You know that might work, I bet i could even incorporate a timer kinda like a time out timer that would reset the relay after a predetermined amount of time and mute the audio coming from the radio. Thanks a buinch

Mike

[pfd radio]

Why can't he assign a call tag to the ID of the transmitting radio on the receiving radio? I think you can assign those to alert on receipt of a particular ID. Set an alert volume that is a fixed level and turn down the volume on the (receiving) radio. When the radio beeps, turn up the volume. When you're done turn the volume back down.

[Mikey]

The mobile radio is going to be in the Radio room and tied to the dispatch consoles via wireline tone remote. I was hoping to have the radio audio muted unitl it received a MDC selective call then the radio would unmute for X number of minutes before it reset back to a muted state. I need to use MDC instead of CTCSS because this radio is a control station that will be monitoring 2 repeaters and then repeaters can't pass the CTCSS tones like i need them too.

[pfd radio]

What about using another signaling format? Like a Quick Call (setup two tones) to be transmitted every time or DTMF. Have the receiving radio unmute when it hears the correct sequence? Instead or the default "OR" setting have it setup for "AND".

I'm pretty sure this can be set in the "signaling squelch" section on the signaling page for conventional personality page.

[WB6DGN]

Check this out.....

http://www.midians.com/html/specspage.a ... +Signaling

Tom DGN

[WB6DGN]

Here's one that will do four different ANI types: G-Star, MDC1200, FleetSync (KWood) and DTMF:

http://cimtechcorp.com/C_Plus_I.asp

Tom

[SlimBob]

The mobile radio is going to be in the Radio room and tied to the dispatch consoles via wireline tone remote. I was hoping to have the radio audio muted unitl it received a MDC selective call then the radio would unmute for X number of minutes before it reset back to a muted state. I need to use MDC instead of CTCSS because this radio is a control station that will be monitoring 2 repeaters and then repeaters can't pass the CTCSS tones like i need them too.

I don't understand your application. Why are you using a radio for what a scanner can do?

[Mikey]

Its not being used as just a receiver, thus i cannot use a scanner. They are going to use it as a Control Station, but the dispatchers don't want to listen to all the "Chit-Chit" of the electric lineman on the channel. They want the lineman and service trucks to "Unmute" the dispatchers radio when they are calling dispatch, and since the mobiles are going thru multiple repeaters they cannot pass the PL tone's thru the repeater to use them, hence why i wanted to use MDC or some other fast signalling protocall.

[SlimBob]

Tell the linemen that the radio isn't their personal CB provided by the company, and tell the dispatchers to get over it. Cite FCC Part 90 regulations.

[Mikey]

Well i would love to do that, but then i would be out a very very good customer and then i would starve and i would have to start looking for another job. LOL

[SlimBob]

Well, are there other users on the channel who are using MDC? Is there a specific subset of users that you just want dispatch to be able to hear? I'm trying to understand why you're reinventing trunking, but I gather that CTCSS isn't a choice. Is this a situation where a common channel is shared by multiple agencies and one agency is using MDC?

There's still the "monitor before you talk" function that needs to be addressed as well.

[Mikey]

Ok, here is the rundown, the main co-op has there own system and the neighboring co-op has there's, at night the main co-op does dispatching for the neighboring co-op. the main co-op's dispatchers do not want to listen to the neighboring co-op radio traffic unless the neighboring co-op needs to contact the dispatcher; since the neighboring co-op goes thru multiple repeaters assigning a pl tone just for dispatch is not an option since the repeaters will not pass the pl tone thru. I was thinking about using MDC Selective Call to open the dispatchers radio to an unmuted state kinda like what the Railroad uses here to alert there dispathers (they use DTMF). I'm not trying to reinvent trunking, this has nothing to do with trunking down to different channels or increasing the capacity of a system, all i'm trying to do is keep the dispatchers radio muted until a end user in the field pushes a button on his mobile to unmute the dispatchers radio.

[SlimBob]

Sounds like a good case for DTMF select call.

I'm going to give them a try and see what does what.

[akardam]

So, if I understand correctly:

- There's two co-ops, co-op A (main) and co-op B (neighboring)
- During the day, each co-op uses their own radio system(s) with their own dispatch
- During the night, both co-op A and co-op B are dispatched by dispatch A
- During the night, dispatch A will talk to co-op B only if co-op B calls them

So, why doesn't co-op B just stay on their own system unless they have traffic for dispatch A?

[Mikey]

Political BS won't let Co-Op B have Co-Op A's Frequency in there radio so that's why we have to install a control station with just Co-Op B's Frequency in it. I know if they could that would make it so easy.

[akardam]

Ok, so dispatch A has a base with co-op B's frequency in it. Here's what you do:

- Setup co-op B's radios with MDC SelCall encode
- Setup co-op B's radios with a MDC Call List with one entry in it (namely, the MDC ID of dispatch A's B-system base)
- Setup a button (ideally) on co-op B's radio for SelCall (or menuitem if there isn't a button available)

- Setup dispatch A's B-system base with MDC SelCall Decode, Unmute Type: And
- Setup dispatch A's B-system base with Sell Call Reset: Auto
- Setup dispatch A's B-system base with Auto-Reset Timer: 10-30 seconds (or whatever is reasonable based on expected length of and pauses during conversation

- Train co-op B's monkeys that when they want to talk to dispatch A in the middle of the night, beep-boop-squawk, and if they pause during a conversation for more than the auto-timer value above (e.g. if it's been more than N seconds since they last talked to dispatch), beep-boop-squawk again

Problem solved.

[Mikey]

Thanks, That's exactly what i was needing. I'm going to set the Auto Reset timer farely long, so the dispatcher will have to listen to traffic at least 5 minutes after the radio has decoded a MDC. Thanks again

Mike