My solar powered WSPR beacon is now active on the 12m band! Tech stack: Navitas 100W Solar Panel, Exide Solar Blitz 40AH battery, Skypearll Solar Charge Controller 30A, 200W 20A DC-DC CC CV Buck module (Robu) - set to output 7.5V, Waveshare ESP32-S3 Zero board, Si5351 with 0.5ppm TCXO, GSD-Hacks-v5 amplifier, DFRobot Gravity Digital 5A Relay Module Photos of components involved (for reference): ...
For HF and amateur VHF bands our WiFi VFO works great. But we didn't have a cost-effective UHF signal source until now… Thanks to Ismo (OH2FTG), we recently experimented with a HopeRF CMT2119A powered board called HOPERF RF module RFM119W-433S1. Here is the CMT2119A powered board in action producing a CW (OOK) signal at ~433 MHz. The stability is pretty good and a bit surprising considering that the board uses a 20ppm 26 MHz regular quartz crystal - not bad! ...
We make heavy use of https://github.com/kholia/Easy-Digital-Beacons-v1 for testing RF amplifiers. This single board is a versatile WiFi VFO and FT8 / FT4 / WSPR beacon. You can also use our CW-SigGen project to generate a suitable test signal.
This ~1W to ~5W WSPR beacon runs continuously on the 10m band. It handles extreme environmental temperatures pretty well (it is 42°C plus here). Our article on this beacon's design and operation will appear in the May/June 2025 issue of the QEX magazine soon. References: http://www.carnut.info/WSPR_Tx/WSPR_Tx.htm QEX May-June 2025 TOC QEX May-June 2025 Perspectives ...