VFO DMR Monitoring issue

[TA2ISO]

I have been using OpenGD77 to monitor DMR frequencies for a while but recently i noticed that when i change the frequency the green led does`t even turn on. When i put the same frequency to Retevis RT3S, the led comes on and it decodes the CC, TG,ID... (RT3S never plays audio though)

439.175 >> GD77 decodes everything, plays sound with no issue (RT3S decodes TG differently, No audio is heard)

440.775 >> GD77 has no signal(Green LED does`t turn on while RT3S has the signal and green led flashes as long as there is signal and decodes CC,TG,ID with no sound)

Another separate issue apart from monitoring is whenever i use different TX and RX frequencies with a dmr channel, the led blinks red for a second than goes off as long as i press the PTT button, it just does`t transmit (I don`t get any signal from the repeater itself, most probably i`m out of the range but i don`t know if this is the normal behaviour ) simplex works fine.

Thank you.

[VK3KYY]

Are these 2 separate repeaters.

I.e This has nothing to do with frequency of operation, and more to do with the repeater you are listening to.

Are both repeaters on the same colour code etc etc etc

[TA2ISO]

Yes, they are separate repeaters. I copied color code from RT3S to GD77 and now it receives the signal and decodes properly, have`t tested audio output yet.

Eventually, GD77 does`t decode CC while in monitor mode but RT3S picks the right color code. Is there a way to implement this for monitor mode only ?

[VK3KYY]

Yes, they are separate repeaters. I copied color code from RT3S to GD77 and now it receives the signal and decodes properly, have`t tested audio output yet.

Eventually, GD77 does`t decode CC while in monitor mode but RT3S picks the right color code. Is there a way to implement this for monitor mode only ?

The DMR chip will not receive unless ip the colour code is set correctly.

The data sheet for the DMR chip does not say whether is is possible to disable this form of filtering

[TA2ISO]

i am going to use RT3S to decode the CC and apply it to gd77 to monitor some specific commercial DMR frequencies then.GD77 decoded sound on both frequencies with no issues. Thank you.

[VK3KYY]

@TA2ISO

Does the RT3S have a way to listen to DMR signals without specifying the colour code value??

Or are you using a scan function on the RT3S to find the CC value.?


If the RT3S can listen to a DMR signal without setting a Colour Code, then technically I think as the RT3S uses the same DMR chip, then it may be possible for the GD-77 to do this.
The problem is however, that the official GD-77 firmware does not do this, so we have no way of knowing how to configure the C6000 chip to do this.


If you are using a scan function in the RT3S to find the value, the OpenGD77 has the same function.

[TA2ISO]

RT3S lets you listen the DMR signals without specifying the color code, that`s correct.

I believe there is an experimental OpenGD77 firmware now which does the same thing, i am going to try it, thank you.

[VK3KYY]

RT3S lets you listen the DMR signals without specifying the color code, that`s correct.

I believe there is an experimental OpenGD77 firmware now which does the same thing, i am going to try it, thank you.

We are trying to implement this fun action in the OPENGD77 but it’s not perfect yet

[TA2ISO]

RT3S lets you listen the DMR signals without specifying the color code, that`s correct.

I believe there is an experimental OpenGD77 firmware now which does the same thing, i am going to try it, thank you.

We are trying to implement this fun action in the OPENGD77 but it’s not perfect yet

Thank you, its going to be really nice to have as a feature.