OpenGD77

elmanoduarte wrote: ↑

Mon Feb 13, 2023 10:22 pm

If there s a way I may see its the MK2 or not!

Not without opening the radio, and the radio is glued together and it is hard to open and then to re-assemble, and can easilty be damaged

Does the radio support Tier 2 DMR (TS1/ TS2) with the official firmware

Hi.

Does the radio support Tier 2 DMR (TS1/ TS2) with the official firmware....

I. Dont know!!!

My experience with this DM-5R:

I could not get the OpenGD77 to work on a single time slot. Always transmitted on both at the same time.

You need the original firmware, "RD-5R Firmware software V2.1.6" in my case, and program a channel. Pay Attention to the following Item
in the channel window: "Dual Capacity Direct Mode", make sure it is hooked.

With this item activated, I was able to talk through my (simplex) hotspot on TS2. And after writing the OpenGD77 firmware this setting
stayed and opengd77 transmitted in TS2. But after manually selecting TS1 and back to TS 2 via *-button, this was gone and it transmitted
in both TSs again. So the DM-5R with the 6000 Chip is capable of single time slot transmitting, but the opengd77 Firmware has the
option DCDM missing in its firmware for DM-5R.


Help text in the BAOFENG CPS:
The Dual Capacity Direct Mode (DCDM) feature supports two simultaneous subscriber transmissions within a 12.5 kHz
channel bandwidth for Direct Mode transmissions. The radios within the same group must use the same timeslot
so that the group using timeslot 1 does not interfere with the group using timeslot 2.
For proper operation, the radios need to identify and track the timeslot structure.
A unique radio is elected as a channel timing leader.
The other radios adjust their clocks to synchronize as possible with the channel timing leader.

This, for me, means DCDM is a switch for TS1/2 or both TSs.

Please, add this option (DCDM) to openGD77. This would make the DM5R a perfect DMR mini radio.

Open GD77 does not transmit on both timeslots at the same time. It does however only support the DMR standard Direct mode for simplex. Direct mode transmits with a 50% 'Single Slot' duty cycle but the transmission does not contain any information regarding timeslot. There is no master timing reference which would normally be supplied by a repeater and used to determine the timeslot. Therefore only one transmission per frequency is supported. The Timeslot selection on the radio makes no difference.

Dual Capacity Direct mode is an enhanced DMR mode that is patented by Motorola. (A recent court case resulted in Hytera having to remove DCDM from their radios and replace it with their own 'Pseudo Trunk' system, M haven't got around to the minor radio manufactures yet!).

Even if we wished to implement DCDM we do not have enough information on how it is done. The HRC6000 datasheet contains no information and the DMR specification only has limited references.

In practice DCDM is not used much in amateur radio systems as we generally have plenty of frequencies available. DCDM is really aimed at commercial users who often only have one RF channel available.

Colin G4EML

Cthulhu wrote: ↑

Mon Feb 13, 2023 1:33 pm

Everything works fine
I have a model with Tire 2
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Did you manage to get it into DMR mode or just FM/FMN ?

Cthulhu wrote: ↑

Fri Feb 24, 2023 9:14 pm

2E0GMY wrote: ↑

Fri Feb 24, 2023 5:12 pm

Did you manage to get it into DMR mode or just FM/FMN ?

Yes
I set up the DMR both through a local repeater and just between two radio stations

"repeaters" are always Tier 2, so the radio this person has, is Tier 2. i.e its the same radio as the RD-5R.
The problem is that Baofeng released the DM-5R in several versions of hardware without significantly changing the model number.

The later DM-5R was called the DM-5R MK2, and was renamed to the RD-5R

Well, the DM-5R does not work with my hotspot in simplex FM, when I use the standard way of operating, i.e. select the channel and cc, and TS2, my Anytone AT-D878 works, the DM5R only, when I select DCDM in the CPS for this channel. It did not work in openGD77 either. Now since I found out about this DCDM-Option (I am not saying, this DCDM in Baofeng Lingo is what it is in Motorola terms) in the DM-5R CPS, I could get my DM-5R to work with my simplex hotspot. What I saw is, I can select the TS2 in simplex, confirmed with my Anytone, which confirms TS2 transmission. If I deselect DCDM, it makes no difference, which TS I select, Anytone always reports TS1. So again, my Anytone doesnt have any problem (hence anytone ) txing in TS2 on simplex channels, Baofeng needs DCDM selected to do that. At least this is what it looks like to me.

Regards from Hamburg, DL9HAM, Michael

DL9HAM wrote: ↑

Sun Feb 26, 2023 5:42 pm

Well, the DM-5R does not work with my hotspot in simplex FM, when I use the standard way of operating, i.e. select the channel and cc, and TS2, my Anytone AT-D878 works, the DM5R only, when I select DCDM in the CPS for this channel. It did not work in openGD77 either. Now since I found out about this DCDM-Option (I am not saying, this DCDM in Baofeng Lingo is what it is in Motorola terms) in the DM-5R CPS, I could get my DM-5R to work with my simplex hotspot. What I saw is, I can select the TS2 in simplex, confirmed with my Anytone, which confirms TS2 transmission. If I deselect DCDM, it makes no difference, which TS I select, Anytone always reports TS1. So again, my Anytone doesnt have any problem (hence anytone ) txing in TS2 on simplex channels, Baofeng needs DCDM selected to do that. At least this is what it looks like to me.

Regards from Hamburg, DL9HAM, Michael

Sounds like you are using the official firmware in your baofeng

Also hotspots do not work well with different radios unless you calibrate the RF freq in the radios to be exactly tgye same , to an accuracy of 100Hz

This is because the ADF7021 in the hotspots is not designec for DMR or other streaming digital audio modes, it is designed for short range telemetry bursts

Roger,
thanks a lot for your help, I built a duplex MMDVM tofay and bought a Retevis RT3S
as well, just because this OpenGD77 such a joy to use.

Both RT3S and DM-5R work well.

Again, thanks alot for your work!

Regards from the "southern most point of Hamburg"

DL9HAM
Michael

Do you have link?