The last couple of years I’m facing much QRM from rf devices and bad solar inverters. To the East the noise increase is sometimes up to 20 dB (!) which makes low signals modes likes FSK/MSK and FT8 nearly impossible.
This is why I decided to build a station which can be placed and controlled remotely. The station is located appr. 3 km of my home QTH and has wired internet. The noise level dropped by 20 dB towards eastern direction, a big improvement compared to my home QTH.
The rf setup consist of a HermesLite2 SDR radio with a 28-144 MHz transverter and a 100W DIY amplifier with external coupler to measure forward and reflected power.
The SDR is controlled by software from SDR-RADIO.COM and running on a small PC which also runs MSHV for the DIGI-modes like FSK/MSK and FT8. The PC is controlled over the internet using a secure RDP connection using VPN (WireGuard).
- topleft : mini PC
- topmiddle : 100W PA with coupler
- topright : SDR with 28-144 MHz transverter
- centreleft : RPI with power relays and rotor control
- centreleft : internet router with VPN connection
- bottommiddle: PSU for PA and rotor control unit
Through the webinterface I can
- control the antenna
- calibrate the position sensor
- wakeup the PC (if powered down)
- turn on/off SDR and PA
- read forward/reflected power
- read temperature of cabinet and PA (@ MOSFET)
The antenna tower can be taken down by 1 person in case it needs adjustment and/or repair.