Soldering 20m and 40m low pass filters from QRP Labs for RPi WSPR

Waiting on a NanoVNA to check out my antenna, not currently getting any spots.

58 points · 8 comments · view on lemmy.world

8 Comments

vk6flab@lemmy.radio · 2 pts · 49d (3 replies)

If you're not getting spots, one common issue is time. Make sure that your clock is properly synchronised.

pageflight@piefed.social · 3 pts · 49d (2 replies)

It's on a Raspberry Pi that's on the network and the clock looks accurate, so I think the NTP sync is working. Thanks for calling that out though!

tasankovasara@sopuli.xyz · 1 pts · 46d (1 reply)

Say timedatectl and you can be sure 😊

pageflight@piefed.social · 1 pts · 41d

Tuned my 40m dipole and now I'm getting lots of spots! SWR was >9 before (resonant frequency around 6.3MHz gah), now 1.2:1. Spots as viewed on wspr.rocks :

wspr.rocks

The setup is running WsprryPi on a (old at this point) Pi B+ v2, fairly cobbled together, followed the guide at brokensignal :

wspr-pi

mushroommunk@lemmy.today · 2 pts · 49d (3 replies)

Any particular reason you didn't lay the third ring flat to reduce coupling between all three?

pageflight@piefed.social · 3 pts · 49d (1 reply)

This is the way it looked in the instructions, didn't realize they might be setting up orthogonal orientations.

mushroommunk@lemmy.today · 4 pts · 49d

Yeah, I don't know how much you know about electronics but usually you want inductors pointing every which way so they don't magnetically couple, but looking at the circuit and the tolerance on the entire thing I guess it's fine, this saves a little space.

I usually play in speaker crossover land (exact same concepts and circuits, low pass filter, high pass filter, etc) and get a little OCD sometimes.

fullsquare@awful.systems · 1 pts · 49d

Most of the magnetic flux should be contained in ferrite, and the part that leaks is pointed at the middle of other ferrite so it shouldn't induce anything. This is fine