RT-3S not being received by Pi-Star hotspot

[DW7GDL]

I added a digital channel with TX and RX frequencies the same as that used by my simplex hotspot, which is a Pi Zero 2 W with an MMDVM hat. I'm running the radio at low power on that channel as I do on my Yaesu FT-70DR. The hotspot has DMR, YSF and POCSAG modes enabled. YSF mode is working with my FT-70. When I press PTT on the RT-3S I don't see any local RF activity on the Pi-Star dashboard. I'm also not receiving anyone on TG 91 slot 1 or slot 2.

When monitoring the hotspot's frequency on an FM radio I hear a burst of I assume data but it's very noisy and sounds like it has a lot of static so apparently the hotspot's radio isn't recognizing it as DMR digital voice. I went to the Signal Identification Wiki and listened to the audio sample of DMR and what my radio's transmitting doesn't sound the same as that. Like I said, it sounds like there's a lot of noise and static.

I've tried different antennas including connecting an outdoor dual-band slim jim. I've tried temporarily setting the MMDVM modem's TX and RX offsets to 0. I've tried different power levels including 5W. I'm starting to wonder if I have a bad radio? That or I've really messed something up or forgotten something in the radio's settings. Could it be a calibration issue?

[F1RMB]

There are so many variables here, check the two following first:
- does the radio's DMRId matches the one defined in your PiStar (as long as it's configured as a private hotspot).
- what MMDVMCal tells about BER (if you're a little too out of frequency, it won't work).

Since your hotspot is simplex, there is no TS1.
When you say you don't hear anyone on TG91, are you at least linked to that TG, does the PiStar dashboard reports some TG91 reception/transmission.

[DW7GDL]

The radio's DMR ID is 5151726, the one I got from RadioID. As far as the DMR settings in Pi-Star go these are all I have:
DMR Master (set to BM_5151_Philippines)
Hotspot Security (set to the password I set on Brandmeister's Self Care page)
DMR ESSID (set to 07)
DMR Color Code (set to 1)
DMR EmbeddedLCOnly (disabled)
DMRDumpTAData (enabled)

If I enable YSF2DMR it lets me set a default DMR TG, and when I link the hotspot to the YSF00002 (YSF3DMR) reflector it works and I can talk to people. (I had a nice QSO with a Moroccan ham on TG 91 once.) But I don't see anywhere to set a TG in Pi-Star's DMR mode settings. I thought maybe the hotspot would pass through whatever talkgroup the radio was set to. (Can you tell I'm a total DMR newbie, hihi?)

Re the BER calibration in Pi-Star it's not even seeing anything from my RT3S, so it's not telling me what the current BER is.

[F1RMB]

Hmmm,

make a configuration backup of your PiStar (you have that in PiStar dashboard, in Configuration page, IIRC), then send it to me, my email is available on QRZ.com.

About the MMDVCal, did you put your transceiver on 433.000.000 (+ or - the RXOffset/TXOffset value), DMR, TG9, then pressed 'b' key in the console then used F/f key to try to get any decoded signal, refining until you get the lowest BER value ?

[DW7GDL]

Hmmm,

make a configuration backup of your PiStar (you have that in PiStar dashboard, in Configuration page, IIRC), then send it to me, my email is available on QRZ.com.

Will do.

About the MMDVCal, did you put your transceiver on 433.000.000 (+ or - the RXOffset/TXOffset value), DMR, TG9, then pressed 'b' key in the console then used F/f key to try to get any decoded signal, refining until you get the lowest BER value ?

No, I'm using Pi-Star 4.2.1 which has a GUI interface for mmdvcal similar to the one in WPSD. I used that.

[F1RMB]

Okay.

I never used that (I don't use any WPSD or official PiStar), I'm always using MMDVMCal from the console (running "pistar-mmdvmcal" script).

[DW7GDL]

It suddenly started working. I have no idea what was wrong but at around 07:15 UTC I had TG 91 time slot 1 selected on the radio which was set to the hotspot's frequency in digital mode, transmitted "DW7GDL testing" and to my surprise had a brief QSO with a ham in southern California who said I sounded good, followed by another good signal report from someone in England. So at least the radio's OK, and now I'm seeing RF activity on the Pi-Star dashboard after having redone the calibration in YSF mode using my FT-70DR to make the TX and RX offsets the same as F1RMB suggested in email. Maybe having RX offset at 525 and TX offset at 100 was the problem.

Thanks to Daniel and everyone for being patient with a DMR and OpenGD77 newbie.
73.

[DW7GDL]

Playing with the RT-3S some more today. I was able to receive from it in Pi-Star's calibration utility and found that an offset of 600 (both TX and RX) gives me a 1% or less BER, both in DMR mode and YSF mode (with my Yaesu FT-70D.) Looks like I'm good to go.

Now I need to figure out how to set the frequency that APRS transmits on. More Fun With Radios.
Edit: I already figured out APRS and verified that it's working.