BATC Forum

I would like to get in touch with other users of the Portsdown 4 - LimeSDR Mini combo to check some things like:

- transmission delay
I measured ~12 seconds from when I press the TX button to when the Raspi GPIO pin 40 (PTT) goes high, while in a 2019 post (related to Portsdown 2020) a delay of 7 seconds was indicated.
choosing "Never Calibrate" or "Calibrate if needed" doesn't change the delay...

- Lime firmware
testcard transmission with various SR and FEC works very well with firmware 1.30. however, when I load the DVB-FW firmware the Lime does not transmit a decodable signal by my MiniTioune. returning to 1.30 everything is fine.

- band viewer
it works, but it seems that the CPU and GPU of my Raspi are very stressed: after about 5 minutes of operation I receive the "excessive temperature" warning and when I check (M1=>Info) I see that the temperature measured by the Raspi exceeds 75° C.

thanks in advance!

i2NDT Claudio

PS
I plugged the Lime into one of the USB3 ports using a USB3 cable 30cm long.
I started my tests with an old version (Buster 202104...) and than upgraded to the latest 202201110 but didn't see any difference.

Hi Claudio

Some of the easier questions to answer

I increased the Lime PTT delay to 12 seconds because some users reported that 7 seconds was not long enough. I think that the time taken before calibration can be variable depending on other parameters. I am about to remove the "Never Calibrate" and "Calibrate if Needed" options as they seem to have ceased to work properly since a LimeSuite software update.

Are you selecting "Lime DVB" as the output device once you have loaded the Lime DVB firmware?

Yes, BandViewer does work the CPU hard. It needs a heatsink or fan for sustained operation.

73

Dave

thanks Dave!
...I missed the Lime DVB output...will try now!

Claudio

GRRRRRRR!
unfortunately it doesn't work!
loaded the DVB FW and changed Output to Lime DVB but still no signal out.
I also checked the "Lime FW Info" but I get the same result as for the FW 1.30!
so I don't know if I have loaded the right firmware.

Claudio