Ismo (OH2FTG) recently introduced me to a bunch of Tokmas RF parts. Out of these, the Tokmas CID10N65F GaN FET stood out. It seems to have a lot of potential (for HF + 6m) at a very low price point. This RF MOSFET part can be purchased from LCSC. It seems Tokmas CID10N65F has the potential to completely replace the RD16HHF1 part from Mitsubishi Electric! Datasheet Datasheet excerpt: ...
I have designed, built, and tested an all-HF WSPR beacon that 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) use. For a 5W (QRO) WSPR beacon, please stay tuned for our upcoming QEX magazine article ;) ...
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). ...
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, cost-effective WSPR pHAT for Raspberry Pi Zero 2 W. Design 3D render: We 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 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. ...