I have designed, built and tested an all-HF WSPR beacon which produces 1W @ 5V and is rugged and cost-effective. Results Power consumption: Around 420mA @ 5V. Cost Cost: Around 500 INR. Time to build Time to build: Less than 30 minutes. Files The files for this project are published here for personal (non-commercial) usage. For a 5W (QRO) WSPR beacon, please hold on for our upcoming QEX magazine article ;) ...
I have built probably the easiest, reasonably rugged and most cost-effective 100mW WSPR (or FT8) beacon. The Build Here is my quick and dirty build with whatever I had lying around: We have replaced the traditional expensive Mini-Circuits transformer with a cost-effective Bourns coupled inductor. Analysis 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 an RF lab on a budget. It is geared towards homebrewers and new amateur radio operators. Budget RF Lab Documentation. 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: FT8Play is crazy good!
Notes to get RSP1 working on Linux and macOS using FOSS drivers (2025) Prerequisites 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. Linux Setup 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. Designs 10m TX-BPF: Results of the Dhiru's Manhattan build: Results of the PCB build: Why use BPFs? 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. ...
I am building an easy-to-use and cost-effective WSPR pHAT for Raspberry Pi Zero 2 W. Design 3D render: We have replaced the traditional expensive Mini-Circuits transformer with a cost-effective Bourns coupled inductor. Status Results: To be built and tested soon! Time to build: Less than 20 minutes
My homebrewed PA0FRI Active Antenna is working well from a very physically constrained location. Design 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. NB: Plug in 75-ohms dummy loads (terminators) on the unused ports of the RF splitter - MX-282 / MX-280 75-ohms dummy loads work fine. ...
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. Design 3D render: Actual picture: ...