Curious about dPMR446

Hi again,

I'm curious to know more about dPMR446 and how it's used compared to the analogue PMR446.  I've had a look on Wikipedia etc but am still struggling with the concepts as the digital system seems very different.

For example, is it possible in theory to call CQ on a dPMR channel, or is it just intended for using between specific users or groups of users, more like a whatsapp call in concept?

Given that dPMR is licence free, how is the issue of Radio ID addressed?  

Is it possible to program a DMR radio like the RD-5R to work on dPMR446? (I do realise that it wouldn't be compatible with the fixed antenna and 500mW limit though)

Are there any specific recommendations for a good introduction to all this on YouTube etc, that would help me start to get my head around it all?

Lots of questions I know

Thanks
- Z

The calling channel is 15 on dPMR.16 is the scan channel.It would be a miracle if You called cq and got a reply.I have tried.

Thanks for the reply!

Now I've managed to get my hands on an RD-5R. Sigidwiki https://www.sigidwiki.com/wiki/Digital_Private_Mobile_Radio_(dPMR) tells me that channel 15 is on 446.190625 MHz but I can't even seem to program that in to the RD-5R, it just jumps to 446.19250 . Frequency step is set to 6.25 KHz but changing that doesn't seem to make any difference.

There is clearly an awful lot that I don't know, and so far Google hasn't been much help in getting me started unfortunately :/

I am curious about DMR as well, is there actually anyone using it? is the range greater than standard analogue?

Alot of people are getting confused about digital so I will try to explain as simply as possible.

Simply put dPMR and DMR are two different standards and are not compatible with each other.

What is called dPMR is actually FDMA teir 1
DMR is TDMA.

FDMA ( dPMR ) uses 6.25khz step
DMR uses 12.5khz step

Channel 1 for DMR and Analogue is 446.00625
Channel 1 for dPMR is 446.0031 ( If I remember correctly )

As you can see the FDMA channel frequencies are not the same as DMR/Analogue.

Most chinese digital radios are DMR but there are a few chinese radios that use FDMA such as TYT DM UVF10 there isn't many of them. I'm not 100% sure but the RD-5R will most likely be DMR.

Realistically you can still use it on pmr446 but lawfully you cannot that is a topic by its self.

If you still want to use it then just program the 16 channels that start from 446.00625.

You will need to know what talkgroup and colour code the other person is using to hear and talk to them but most DMR radios that I've came across just use CC1 and TG1 so that is a start.

On PMR446 ( and any radio to radio ) internally the time slot cannot be changed and it will always use timeslot 1 regardless of whether you change it to timeslot 2 unless you have a radio capable of DCDM but that is a whole story by its self and I'm trying to keep it as simple as possible.

I've just put my RD-5R onto the GD77 open source modified software. Far better now all though the buttons operate differently now so need to keep a reference picture to remind me the functions. Now it can scan all zones at once.

Hi

What sort of range do you get with the PMR?

Complete noob to this!
Thanks. 

John

Hi John, as a general rule line of sight but from high ground some pretty amazing distances have been achieved. If you google UHF propagation you should find more detailed info.

73's Gary.

Tristar wrote:

Hi

What sort of range do you get with the PMR?

Complete noob to this!
Thanks. 

John

In the right conditions / locations you can get some long ranges....these two videos are of the same QSO between Southern England and Normandy, France. This contact was made using 100% legal radios with 0.5 Watts power output and fixed antennas.

https://www.youtube.com/watch?v=fxaQwQZdlCc

https://www.youtube.com/watch?v=MqDDguVwqQo&feature=youtu.be

Many thanks Pagan
I’ll take a look. 
Sounds quality contact
Especially on 0.5 watts. 

Brilliant!,

John