DTR 550 problems

OK, just bought 2 DTR 550’s for evaluation and about to give up!!

I can’t get them to work as described in the manuals, I am using the CPS to program from my PC and have done a bit of testing, they only work when everything is on one channel, regardless of what the manual and the Motorola website says!

Here is the example:Two Radios “Eric” and “Kristen”.

Radio Eric – Channel 8
Radio Kristen – Channel 8

According to the manual, a radio can receive a private call regardless of channel, ie Eric can have Kristen programmed as a private contact at channel 1. BUT it doesn’t work that way. The only way a private call works is if the private call is on the same channel as both radios are set to, ie channel 8 in this example. If I change a private contact to channel 1 it doesn’t work, manual says it will.

For public groups, again the manual says a group can be on any channel (channel scan is on). So I should be able to make a public group “cave” on channel 10, ID 2 and be able to select that public group in the radio, press PTT and receive on the other radio (which also has the public group programmed into it on ch10, ID2, scan on) – doesn’t work. The only way I can use a public group is if it is the same channel as the radio is set to, in this example channel 8.

The whole idea of these radios is that I could use multiple channels, for example moving away from the public group channel and have a private conversation on a separate channel, thus keeping the first channel free, ie other radios would continue to talk on channel 8 as I was have a private conversation on channel 10 (either private or private group)
Any help on how I can use multiple channels? Am I doing something wrong, is the manual wrong or the CPS??

On a related note, what is the change in the firmware between R5E.06.00 and R5E.06.02 for the DTR550?? - I got one of each!


…or do I misunderstand and everything can and should go on one channel? - ie that multiple communications can occur on one channel at the same time?


Yes, that is the beauty of digital radios. They can all occupy the same “channel” simultaneously.

They don’t use a real channel in the traditional sense. It is more of a programming algorithm that specifies the actual frequency they use as they hop from frequency to frequency every 90 milliseconds. This is why several communications can occupy the same “channel” at once.

Your first step is to set ALL your radios to the same channel and the same ID number. That is the only way they work.

Once you have them all set to the same channel and same ID number, you can dive back into the manual and look up how to program multiple public and private groups. All your groups will occupy the same frequency programming algorithm.

Because there are 10 channels and 100 ID numbers, there are thousands of combinations and it is virtually impossible that someone else will be on your exact channel and exact ID number as you within your range.