BATC Forum

Hello all,

I'm new to the Langstone, my initiation being coincident with the Raspberry Pi update issue last week so I'm running very recent software. The system (Pi 4 with official 7" screen and Pi 4 PSU) is now up and running but I've noticed that it creates an S6 level of noise on 80m. I can reduce this by disconnecting the ethernet cable but then the PTT becomes extremely slow to respond - in the order of 10-20 seconds. Plugging the ethernet back in normalises the PTT response but also the noise. I have another internet connected Pi 4 doing WSPR that does not create noise but it's running headless so perhaps the screen on my Langstone system is the origin? The bigger issue though is the PTT response as I don't want to run all the time with an internet connection. Does anyone have any ideas?

73 Chris G4SDG

Hi Chris

Are the power supply arrangements for the 2 Pi 4s the same? Whilst the screen might be the issue (and possibly its power wiring?) I would look to the power supply first.

No ideas on the PTT - my Langstone runs fine both on or off LAN. Does it affect both the on-screen PTT and the hardware PTT switch? Do you have the resistor pull-ups installed? Particularly pin 11?

Dave

Thanks Dave. As it happens I was talking to Martin G4FKK and after comparing our set-ups he suggested a complete re-install using a different SD card and that has solved the PTT oddity. Goodness knows why though!

As for the interference I'll check that tomorrow to see if it has changed when 80m is a bit less active. I've powered the Pi 4 from an official Pi 4 power supply and then powered the screen via the jumper wires which is the same way Martin's done his and he doesn't suffer a noticeable noise increase but I think his general noise level on 80m is higher than mine. My shack isn't best placed in relation to the 80m antenna but I've never noticed significant noise coming from all of the PCs, screens, PSUs etc in there when I've done "mains-off" tests with a battery powered receiver.

73 Chris G4SDG