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I have built probably the easiest, reasonably rugged and most cost-effective 100mW WSPR (or FT8) beacon. Here is my quick and dirty build with whatever I had laying around: We have replaced the traditional expensive Mini-Circuits transformer with a cost-effective Bourns coupled inductor. Power consumption: Before RF generation starts -> 20mA @ 5v. After RF generation starts -> 52mA @ 5v. So the power input consumed in the RF generation process is more than 150mW it seems (which is good). ...

The Easy WSPR Encoder can be accessed here. Update: You may find this software more useful.

Bharath and I have written our thoughts on building a RF lab on a budget. It is geared towards homebrewers and new amateur radio operators. We maintain this documentation here. Have fun! :-)

The Easy FT8 Encoder can be accessed here. In the near future, we want to add the K1JT's original FT8 encoder functionality as well. Update: https://pengowray.github.io/ft8play/ is crazy good!

Notes to get RSP1 working on Linux and macOS using FOSS drivers (2025) Please use a mainstream Linux distribution like Ubuntu 24.04 LTS (or later) or the latest Raspberry Pi OS. Using a Raspberry Pi is NOT recommended as it has quite a bit of power supply noise on the USB ports, which reduces the performance of the connected SDR. On Linux, add the following lines to the /etc/modprobe.d/blacklist.conf file ...

Some weeks back, we published our designs for building reproducible TX-BPF filters easily. 10m TX-BPF: Results of the PCB build: While many amateur radio operators focus solely on antenna optimization, the significant benefits of TX-BPF filters are often overlooked or under-discussed in the hobby! Even with HOA antenna restrictions, you can still optimize your station's performance through proper TX-BPF filtering. We have reduced the cost of such filters by using cost-effective 1kV SMD C0G caps instead of hard-to-get and "probably-obsolete" Silver Mica caps. ...

I am building an easy-to-use and cost-effective WSPR pHAT for Raspberry Pi Zero 2 W. 3D render: We have replaced the traditional expensive Mini-Circuits transformer with a cost-effective Bourns coupled inductor. Results: To be built and tested soon! Time to build: Less than 20 minutes

I am a bit late to realize that Ubuntu is going downhill and has been for a while. Here are a couple of things of things I have noticed about Canonical/Ubuntu: Forced paid updates even for active life OS versions Series of bad decisions (Mir, Unity, Upstart, Snaps) causing pain all around Inflicting slow and buggy snap applications on their users. Not listening to feedback from users - Firefox Snap is really slow to launch, especially on older computers. ...

My homebrewed PA0FRI Active Antenna seems to be working well from a very physically constrained location. 3D render: Schematic: Results: The antenna is connected to a RSP1 Clone SDR which is running custom FT8-band-hopping software. I am using a SOLID 4-Way 5-2400 MHz RF splitter to connect multiple SDRs to the same active antenna. Time to build: Less than 45 minutes for the PCB. The mechanical aspects (loop construction and boxing) can take a while. ...

Sometimes we all need a bit of QRO - Life's too short for QRP sometimes. So we give you the Baby-QRO switching amplifier! This Baby-QRO switching RF amplifier design is inspired by the wonderful Single NXP MRF-101 Eval Board project by Jim Veatch. Thank you Jim! Instead of using the expensive MRF101 MOSFET, we use fast SiC MOSFET(s) from Wolfspeed / SUPSiC. 3D render: Schematic: ...