Peter (PA3PM) started to do some experiments with the ADALM SDR. This type of SDR is available for about $100 and capable of transmitting and receiving – even full-duplex – between 70 MHz and 6 GHz with a bandwidth up to 56 MHz. It’s capable to make DVB-S (and DVB-T) transmissions out of the box.
This week I’ve received my box. Within half an hour I was capable to produce an image on the PI6ATV repeater using the 1265 MHz DVB-S input and an old webcam. This is done with the native 0 dBm (1 milliWatt!) output of the SDR connected to my 120cm dish. I do have to note that there is a line of sight with the Gerbrandy tower more than 30 kilometers away.
Next is to amplify the signal using some RA18H1213G modules (18 Watt FM, 3 Watt DVB) on 23cm or some 3G modules still on stock for 13cm. And… more important, to filter the signals since the SDR will create harmonics.
- Separate RX and TX connector
- 12 bits DAC/ADC
- USB2 interface
- 65.1 kSPS to 61.44 MSPS (200 kHz to 20 MHz signal bandwidth)
- 325 to 4 GHz tuning range (70 MHz to 6 GHz after ‘mod’)
- Runs Linux with an open design. 2 Second boot time.
- 32 MB of Flash, 512 Mb of DDR3 memory
- Only 72 parts on the board, thus cheap
- Better RF than AD9363 specs
- Highly linear broadband transmitter
- Transmit (Tx) error vector magnitude (EVM): −34 dB
- Tx noise: ≤−157 dBm/Hz noise floor
- Tx monitor: 66 dB dynamic range with 1 dB accuracy
- 2.4 Hz local oscillator (LO) step size
- NO RF Shielding, NO RF Filtering. Use a low-pass filter!
- Linux IIO interface: USB, Ethernet, Mass storage, Serial, DFU
- Also capable to act as USB Host device
- Very easy firmware update. Drag, drop and reboot. (and pray…)