Tangara is a pretty awesome project - no doubts about it. I found this review of Tangara's design pretty interesting and educational. It has inspired us to build a similar FOSS DAP product but at a much lower cost of 40 USD (that being the launch price of Sansa Clip in year 2007). The idea is to deliver '90% of the value' of Tangara in a slightly smaller (but fatter) and more cost-effective package. ...

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 lying 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 an 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 Dhiru's Manhattan build: 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. ...

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 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 is 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. 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. ...