RF Hacking

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

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: ...