Hamradio stuff

RedPitaya SDR project

I use simple and efficient digital setup for 10GHz based on low-cost RedPitaya and Kuhne 10GHz/144MHz transverter. The RedPitaya uses 125MHz sampling and originally it has 60MHz low-pass filters installed on-board. I have removed the filters and installed the new 144MHz filter instead. I use under-sampling on 19 MHz to get to 144 MHz.

I also have made a new 125MHz oscillator locked to external 10MHz GPS/Rubidium reference, modification is describet here

Complete radio:




 10 MHZ locked TCXO


RP with input filter removed


Guys from RedPitaya were so kind to give me the Audio codec. The schematics - how to connect codec can be found here.

WM8731 Red Pitaya
SCK --- DIO4_N (E1) Pin 12
MISO --- DIO5_N (E1) Pin 14
MOSI --- DIO6_N (E1) Pin 16
ADCL --- DIO7_N (E1) Pin 18
SDA --- (E2) Pin 10
SCL --- (E2) Pin 9
3,3V --- (E1) Pin 1 oder 2
GND --- (E1) Pin 25 oder 26

source: http://forum.cq-nrw.de/viewtopic.php?t=129  and  (from the same source)


For the EME digital modes i use PowerSDR and WSJT-X. The commands between the two are sent via Virtual serial ports (VSPE emulator) software.

Audio is transfered over VB-Audio virtual cable.




VK7UM - S57RA / 16.386km contact with only 60cm antenna

After some effort - moving air-gun and extending tx waveguide, rx and controll lines, we managed to make a contact on 10GHz with Rex - VK7MO from Hobart/Tasmania. We repeated the contact the day after with smaller antenna and less power on his side. 

First day Rex used 120cm antenna and 90w and day later only 60cm antenna and 50W. Equiment on my side was 3m dish, abt 150w at feed, 0.8dB preamp, kuhne 3cm transverter,  and my low-cost SDR with  RedPitaya and PowerSDR radio.

Distance between stations (jn75ap in qe36wv) is 16386.66Km.

The radio and PA were developed at EIUS d.o.o.

Echoes from the moon on 10GHz

Autumn 2017, new 10GHz setup, 400W power amplifier, SDR RedPitaya radio, 1.4dB preamp. See more photos or listen to the Moon echoes in the Video...