Mixed Mode

[AEMTKieran]

What does it mean when someone says a radio should be programmed in mixed mode? I have an Astro Saber I'm going to send out for programming, and I found P25 repeaters in the Florida area and Denver area I am going to have put into the Saber...the repeaters have both analog and digital, so I've been told my radio should be in mixed mode. Help out a Motorola newbie, please! Thanks.

[studgeman]

There are two ways that "mixed mode" is used. The first way, "mixed mode" is used to describe the entire radio or radio system, where the radio, repeater, basestation etc. can be programed to operate in analog and digital mode.

The second way referes to programming of an indivudal channel in an radio. Most P25 radios can be programmed for Analog only, Digital only or both (mixed mode). When programming for mixed mode, it can be a little tricky. I haven't personally programmed an Astro Saber, but what you need to look for is how to program it so your initial transmission is in the mode you want.

Quick example, Some PDs will run entirely digital, but leave the programming mixed mode in the system and subscribers, when another user comes onto the system in analog, it will drop all the users to analog for interoperability.

Mixed mode progamming has logic built into it at the subsciber level so that if the radio recieves a digital transmission, it will respond in digital. If it recieves an analog, it will respond in analog.

Mixed mode can be quite tricky, have fun!

[Josh]

Long story short, for programming, you're going to need to program two channels. One (or both) with mixed mode RX (because Mixed mode is for RX only on anything but repeater programming).

One channel will TX in digital, the other in analog. In mixed mode you can hear both analog and digital on the same channel, but in order to TX, you'll need to select which transmission mode you want to communicate in.

[PeterGV]

studgeman is exactly correct. Let me see if I can provide some more Astro Saber specific information to add to what he said, so you know what to tell the programming folks.

When you have a channel that has both analog and digital info on it, the important info to provide the folks programming your radio (aside from the frequencies) is:

a) Any PL/DPL used for analog transmit and receive -- or if you want CSQ.

b) The NAC (network access code) for transmit and receive for digital transmissions -- If you're not familiar, the NAC is roughly the digital equivalent of the analog PL tone.

c) Whether you want the radio to transmit in analog or digital when you PTT

d) Whether you want the radio to restrict digital reception to only those messages with the NAC you indicate, or whether you want the radio to receive any digital transmissions regardless of NAC (the latter being "digital CSQ")

There are tons of other more "exotic" options, of course... like direct support, digital talkgroups, and the like. But those are the basics.

Hope that helps,

de Peter K1PGV

[VPD463]

Originally Posted by studgeman

Quick example, Some PDs will run entirely digital, but leave the programming mixed mode in the system and subscribers, when another user comes onto the system in analog, it will drop all the users to analog for interoperability.

I think studgeman explained it well. The above section is important where I work. My agency uses an analog system and we frequently colloborate with another using a digital system. Fortunately, the other agency uses mixed mode so we can still communicate with their personnel. You'll need to decide whether interoperability may be important for you.