July 2017 Second Sunday Reminder

WSPR on Raspberry Pi & QRP Filter

Project Description

There are a several options for this session:

  1. Build a QRP Filter (Low Pass Filter, specifically, one of these)

  2. Setup a Raspberry Pi for WSPR transmission, using the QRP Filter to enhance the TX.

WARNING: This project has the potential to damage your Pi. Though we’ll take great precautions to prevent that, I recommend using one of your older Pis or one you’re okay with potentially frying. The project involves connecting the clock pin directly to an antenna, which has the potential for feedback current above what it can handle. We’ll use a Schottky Diode on that pin to try avoiding that.

  1. As usual, you are welcome to just come hang out and get to know some fellow hams.


To recoup the cost of the components, we ask for a $5 donation if you build a QRP Filter. You can just bring cash to the event or pay via PayPal.

What to Bring

Project 1 – Filter Only (20m or 30m): No need to bring anything, I’ll have a couple of soldering irons and solder as well as the kit. You’re welcome to bring your own iron, solder, and if you do, something to set down under your work area (cardboard or silicon mat). That does tend to speed the build up a bit.

Project 2 – Bring a Raspberry Pi, preferably older or that you’re okay with potentially damaging (see warning above). Also, you’ll need to be able to SSH into it, so it needs to be a WiFi capable Pi or one that has an Ethernet port. (edit) Or have a display and keyboard for direct commands. Also, don’t forget your SD Card to run the OS. I’ll have an image with WsprryPi already loaded, as well as the WiFi password.

NOTE: TXing on 30m requires a General license or above, however, the WSPR range on 20m is within the range for Technician level.

If you don’t have a Pi, you can purchase one locally at MicroCenter or online from many different retailers, including Amazon.

Hope to see you there!

P.S. We’ll also be conducting a FREE license testing session from 12 PM until 2 PM, just before the tech session, same room. So if you’ve been meaning to get that test out of the way, this is also a good opportunity for that as well.

To sign up and get directions go to the MeetUp site by clicking here: https://www.meetup.com/Atlanta-Radio-Club/events/240890571/

2:00 PM at PDK – see you there!

Leave a Reply