OKDXF published the W1FB design notebook on their website https://www.okdxf.eu/files/W1FB%20Design%20Notebook.pdf This notebook contains a lot of interesting circuits for amateur radio experimenters. Check it out.
W1FB-Design-Notebook-1Tag: SSB
Single Sideband (SSB) modulation on the Raspberry PI
F5OEO has recently written some code to transmit a SSB signal using just the hardware in the Broadcom SOC chip on the Raspberry Pi. You can find more info on this link http://www.rtl-sdr.com/transmitting-fm-am-ssb-sstv-and-fsq-with-just-a-raspberry-pi/
I tested the code on my RPI on 6m via a cable connection. It worked OK. If you look at the S-meter you can see that the envelope is constant. This is due to that the RPI has no way of modulating the envelope so the software actually modulates frequency. It is kind of constant envelope SSB.
Below you can see what the signal looks like. (This is received on a SDR via an attenuator). The signal is a bit too wide. However cool test.
If you want to test the code yourself you can check it out over on F5OEO at github https://github.com/F5OEO/rpitx
Warning: do not connect the RPI GPIO output running this code to an external antenna without a bandpass or lowpass filter and a valid amateur radio license. Never transmit any signal outside the amateur bands.
Contesting from CR3L (Madeira Island) with RRDXA
I am back from the megalocation at CR3L Madeira Island after working CQWW SSB with the R25 RRDXA team. It was a great weekend and we achieved good run rates however our targets were set at a higher QSO number. Since CR3L is in AF zone 33 we worked three pointers both to Europe and US and got a good score. That was fun. Claimed score looks like we will be around number 9 worldwide (a bit above 15M points). The CR3L Madeira station is located at Santana in a mountain side on Madeira overlooking salt water. Thanks to the team! Ops: DF4UM, DH4JQ, DJ5KW, DJ8VC, DL1EK, LB3HC . Stay tuned for 2013 events.