MMDVM hotspot ,TX problem

[ap2mhc]

Greetings.
i have an mmdvm hotspot that is connected to tg 91, I can receive it on my ailunce HD1 but i cant transmit on it, if immediately press ptt after receiving any call , then i am able to transmit to hotspot and it shows in the dashboard,other wise if the talkgroup is silent i can't transmit on it,

i am unable to address the issue.

Help needed

[AF6VN]

Are you sure the radio is configured on a channel for talk-group 91? Depending upon configuration your "working" replies might be going as private replies to whatever DMR ID came in to it.

Second, what setting(s) does the channel have for color-code? It may be that you have some setting that only allows transmitting when the color-code is an exact match (though I've not seen this condition with my TYT units... "Admit Criteria: Color Code", "In-call Criteria: Always"). I've never really found clear documentation on what those options really control (Admit has always/channel free/color code). My Anytone D878xxxx has "TX Permit" with always/channel free/Different Color Code/Same Color Code -- I have it set for "different". According to the hint text in the editor:

• Always -- radio will transmit at any time
• Channel Free -- radio will transmit only if there is no other traffic on the channel
• Different CC -- radio will transmit on a busy channel IFF the color code is a mismatch
• Same CC -- radio will transmit only if a received signal on the channel matches the configured color code

There is no explanation as to what happens if one has one of the CC options selected, and there is no recently received traffic (I'm presuming "no recent CC" qualifies as "different", but a strict interpretation of "same" could mean the radio can only reply during the interval when the received contact is still active on screen).

A third factor -- may not apply (I run D-STAR and DMR on the same unit) It sometimes takes me two or three PTT cycles (of a few seconds each) when the Hotspot is in "Listening" (vs "Listening DMR") for the decode to figure out what mode the inbound RF is using.

[UT4URT]

Greetings!
I have exactly the same issue with my MMDVM. I have been experimenting with my radio channel settings, CC settings, and private/group settings for Contacts. It took some time but had no affect on the issue in general at all. Still I can listen to TGs(which I subscribed to) but I can't TX when I push PTT to call any of those TGs. And, yes, i can Tx immediatly after someone who talks on GW releases the PTT. I can even Tx on TS2 while TS1 is active, or can transmit on TS1 while TS2 is active.
Well, I just have one question: Is the problem is solved? If yes, which steps proved to be helpful for that?
Thank you.

[AF6VN]

You mention TS1 and TS2... To my understanding, the only boards which make use of both time slots are the "dual" (and not "dual BAND") versions. These operate as mini-repeaters, not plain simplex hotspots.

If so, your channel configurations will need to incorporate the correct offset between the Rx and Tx modules.

Also, what radio, what DMR server? (The comment about "subscribed to" is a bit perplexing -- Brandmeister, for example, has dynamic talk groups; the first time you transmit on a TG it becomes the active TG for your node, and will stay active for around 15 minutes if a repeater node, perpetually if hotspot. The active TG is the only one on which you will receive traffic.)

Other than that, I can't offer anything new. Once I learned the hassle of having to define TGs, THEN defining a channel for each TG and repeater/hotspot combination, and setting the color code permits, my radios have just... worked!

[UT4URT]

You mention TS1 and TS2... To my understanding, the only boards which make use of both time slots are the "dual" (and not "dual BAND") versions. These operate as mini-repeaters, not plain simplex hotspots.
ch
If so, your channel configurations will need to incorporate the correct offset between the Rx and Tx modules.

Also, what radio, what DMR server? (The comment about "subscribed to" is a bit perplexing -- Brandmeister, for example, has dynamic talk groups; the first time you transmit on a TG it becomes the active TG for your node, and will stay active for around 15 minutes if a repeater node, perpetually if hotspot. The active TG is the only one on which you will receive traffic.)

Other than that, I can't offer anything new. Once I learned the hassle of having to define TGs, THEN defining a channel for each TG and repeater/hotspot combination, and setting the color code permits, my radios have just... worked!

Yes, the hotspot is really dual, it is set for two different freqs - one for Rx(431.200) and one for Tx(438.800), so the offset is 7,6MHz.

As regards to the radios, for the purpose of hotspot testing I use two types of radios: Motorola Mototrbo R7(UHF) and dual-band Baofeng DM-1801. Both radios have similar settings(freqs, contacts, channels which I use to work with my hotspot are all the same on both radios).

Currently I use BM 2551 server, and before it was BM 2001.
On both radios a separate channel is created for each TG. And each of these channels are named after the names of TGs. When creating channels i used corresponding contacts. The contacts had the same IDs and ColorCofes(CC) as the IDs and CC of corresponding TalkGroups, i.e. 255, 2555, 25501, 25504, 25516, etc.

To all said above I can add that I set the RF power to minimum. This had no positive affect: I still can't Tx to the TGs.

By the way, here on the forum I read something on the necessity of calibration of MMDVM. I do not have a clear understanting so far of what it is for. The idea was it's mandatory to use pistar-mmdvmcal utility to do proper settings to the modem. Are you familiar with this operation? If this procedure is realy needed and helpful for my no-Tx issue, i would be happy to learn how to do it step by step.

[AF6VN]

My hotspot runs a DV-Mega board, which is not supported by the MMDVM calibration routine.

Calibration is used to fine-tune the less-than-ideal MMDVM frequencies to better match the frequencies programmed into the radio; too great a mismatch and the BER will be extreme. Note that, with two radios, it is possible to encounter the situation where one radio may need a -cal value, and the other needs a +cal value -- in that case you will have to hope you can find a compromise value that works with both radios.

For those moments when your board does respond to the PTT signal, what does the Pi-Star dash board show for BER?

[UT4URT]

My hotspot runs a DV-Mega board, which is not supported by the MMDVM calibration routine.

Calibration is used to fine-tune the less-than-ideal MMDVM frequencies to better match the frequencies programmed into the radio; too great a mismatch and the BER will be extreme. Note that, with two radios, it is possible to encounter the situation where one radio may need a -cal value, and the other needs a +cal value -- in that case you will have to hope you can find a compromise value that worndks with both radios.

For those moments when your board does respond to the PTT signal, what does the Pi-Star dash board show for BER?

Hi, Dennis!
After quite a lot of struggling with this issue by now, I don't even know where to look for solution. Finding a compromise value ideal for both radios is not even a priority for me now. I would be already happy to make at least one radio make friends with the hotspot. I'm not 100% sure the calibration will solve the problem, but why not to try at least.
Sorry if I misunderstood your question, but I unfortunately just can't tell you what the Pi-Star dash board shows for BER. This is because my hotspot plainly ignore ANY Tx signals from any of my radios. The hotspot does not respond to my radios. I checked the radios, separately cheched each one of them, no problem found. Each radio work fine either in direct communication with another radios in FM&DMR or via local FM repeater.
If the calibration should be performed in CLI on my shotspot, which command is to be used for that? My command line looks like pi-star@pi-star(ro):~$ ,
now i want to make sure which command to type to encrease\decrease Rx offset?

[AF6VN]

Sorry if I misunderstood your question, but I unfortunately just can't tell you what the Pi-Star dash board shows for BER. This is because my hotspot plainly ignore ANY Tx signals from any of my radios. The hotspot does not respond to my radios. I checked the radios, separately cheched each one of

Perhaps I misunderstood your earlier post...

And, yes, i can Tx immediatly after someone who talks on GW releases the PTT.

That was interpreted to mean that you could get a connection when (immediately) replying to something that just came in. Which led to my comments that some radios supported a "direct reply" mode, which basically configured the channel to the exact specification of the inbound traffic, before later reverting to the programmed specification.