100mW WSPR Beacon (2025)

I have built what is 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 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 input power consumed in the RF generation process is more than 150mW (which is good). ...

February 14, 2025 · 1 min · 171 words · Dhiru Kholia

Easy FT8 Encoder

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!

February 13, 2025 · 1 min · 29 words · Dhiru Kholia

My PA0FRI Active Antenna

My homebrewed PA0FRI Active Antenna is working well from a very physically constrained location. Design 3D render: Schematic: Results The antenna is connected to an RSP1 Clone SDR 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-ohm dummy loads (terminators) on the unused splitter ports; MX-282 / MX-280 75-ohm loads work fine. ...

February 8, 2025 · 2 min · 335 words · Dhiru Kholia