REV2.1 No longer Receiving Packets

[sethpark777]

Hardware Version: T-TWR REV2.1
Firmware: ESP32APRS_T-TWR V0.4

I'm trying to do some troubleshooting here, so maybe someone can offer some ideas/assistance.

I have been using the 2.1 board for a while now, and it has been working well. However, the other day, i noticed that i was not getting any RF packets, only packets from the internet via the igate. I had thought maybe it was just bad conditions and i was not receiving any packets. But this continued for a while, and then i noticed that the green RX LED was never coming on. I have tested with a handheld nearby (applied attenuation) to double check that there are no RF packets being received.

Is it possible that the front end has been blown out somehow? Transmitting still works as expected and can be received via handheld or SDR.

I have been running no squelch, and a volume of 6-8, depending on me playing around with things.

Any thoughts would be appreciated!

[kkwestt]

same problem on v2.1

[nakhonthai]

V2.1 hardware not support and i don't have this device for test.

[sysadminpower2019]

can we buy you a 2.1 to continue dev work?

[podgorskik]

Hi, I noticed similar problems on my board:
Hardware Version: LILYGO T-TWR Plus
Firmware Version: V0.4
RF Analog Module: MODEL: SA868_VHF
In my opinion it isn't SW but HW problem
I also noticed that the problem does not occur after completely turning off the transmitter (all - tracker, digi and igate set to off.)
My first suspicion was that using a poorly matched portable antenna would have an RF impact on the system's operation.
However, when testing with an external antenna or dummy load, the problem continued to occur, but less frequently.
Another assumption was that the problem could be caused by a large change in current consumption when the transmitter was started.
I mounted a 100µF electrolytic capacitor directly on the SA868 power pins (VBAT, GND) and placed it in the free space on the other side of the board next to the GPS antenna.
After this modification, the problem completely disappeared, regardless of whether I use low or high power. I'm not sure if this is a universal solution that also addresses similar stability issues, but in my case it works great.

[podgorskik]

I would like to add I tested this my solution by over 24h and no any problem apeard. Earlier The Rx was blocked after 2-3h.
I think it's worth to check :)
Regards - Krzysztof SP9SVH