Inbuilt band-hopping in WSJT-X 3.x

WSJT-X 3.x has inbuilt support for band hopping! RX results from an experimental version of DDX: This is super useful for monitoring FT8 traffic on multiple bands. References: https://github.com/kholia/libmirisdr-5 https://sourceforge.net/projects/wsjt-x-improved/files/

October 18, 2025 · 1 min · 30 words · Dhiru Kholia

Emulating a full FT8 band for 'real'

This code generates a .wav file which emulates a fully-populated FT8 band! This .wav file can then be played with rpitx on actual air (well on a dummy load) for receiver testing purposes. rm mixed.wav; sox -m *.wav mixed.wav sox mixed.wav -r 48000 sampleaudio.wav Now play sampleaudio.wav using https://github.com/F5OEO/rpitx. I have tested https://github.com/F5OEO/rpitx on Raspberry Pi Zero 2W TX'ing @ 14.074 MHz. References: ...

October 17, 2025 · 1 min · 69 words · Dhiru Kholia

FT8 Decoding Challenges on Android

Here is the FT8 WAV test file. On an AMD64 machine: 1 second using the fast decode settings. We were able to get the MSHV's FT8 engine to work on Android, thanks to the work done by https://github.com/sannysanoff/SDRPlusPlusBrown folks. Around ~4.5 seconds to decode the same file. This is why we can't really have full-blown realtime FT8 decoder(s) on Android just yet! Idea: But we can surely use this full-blown FT8 decoder in our FT8 Decoder app which has no realtime requirements! ...

September 29, 2025 · 4 min · 657 words · Dhiru Kholia

Ideas for a 2m (144 MHz) WSPR / FT8 beacon

I am posting an early design sketch of a 2m WSPR beacon. Here are the key points: 25 MHz HCI 0.5ppm TCXO powering the Si5351 module instead of the 26 MHz TCXO. If this fails, we can use a 10 MHz OCXO instead (a bit out of spec but works fine). Tokmas CID10N65F GaN FET might work @ 144 MHz as the 'final'. If not, use Mitsubishi RD15HVF1-501 MOSFET as backup. ...

April 15, 2025 · 1 min · 172 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: https://pengowray.github.io/ft8play/ is crazy good!

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