recorded signal – QUADRUS SDR

I had a chance to try and test the DRU-244A digitizer board and the SRM-3000 HF SDR receiver utilizing said hardware platform. I took some recordings in the 20 m (14 MHz) and 15 m (21 MHz) bands, which can be used to test the SDR receiver software offline. The SRM-3000 allows the direct recording of the incoming IF signal into a binary output file.

The file stores the IQ samples as generated by the DDC hardware with the selected sampling rate (bandwidth). Unfortunately, the file itself does not store the bandwidth information, so I’ve encoded that into the file name. During playback, you should set the same bandwidth on the Option/Settings panel.

The two higher bandwidths (200 kHz and 400 kHz) are only available for the four channel (or less) operation mode. This may be set manually, by editing the config file.

After you’ve set up the appropriate bandwidth for your recording, select the “FILE” input on the control panel. A standard file open dialog will appear, where you may select a *.DSRS file for playback.

After starting the receiver, you will see the IF spectrum, and you can place your demodulator anywhere within the IF spectrum. To increase the volume, set the AGC max gain to 100-120 dB (instead of the default 60 dB) on the Option/Setting panel, or use the manual gain to set the volume. The file is played back continuously in loop back mode.

I’ve made some 50 kHz and higher, i.e., 100 kHz and 200 kHz, bandwidth records.