Thursday, January 3, 2013

New 20m SDR receiver added to WEBSDR

 New 20m SDR receiver added to WEBSDR

(Softrock  receiver) Where can I get a softrock recever

I have build my first Softrock Ensemble RXTX for the 30m, 20m and 17m bands.
more details on the receiver and the assembly details can be found at

Building the Softrock Ensemble RXTX
Testing the Local Oscillatory
Signal is pure sine wave
I had to add a command line utility to the Linux webSDR server to control the frequency of the receiver via usb port with the following program usbsoftrock.
The program can be found on Google code
You will need to compile the code before you can use it.
here is the command that you could use after compilation

sudo usbsoftrock status
Version     : 15.12
USB SerialID: PE0FKO-0
Startup Freq: 14.210000 (x 4.00)
Xtall Freq  : 114.285000
Smooth Tune : 3500 PPM
Si570 I2C   : 55 Hex
  BPF Enabled: 0

Set the frequency you require
   sudo usbsoftrock set freq 14.210

The frequency was a few khz lower and I had to calibrate the frequency using the following command. You can retrieve the frequency at which your Si570's crystal oscillates with the command sudo usbsoftrock calibrate

Version     : 15.12
fXTALL = 114.207544

Calibrating the frequency with the value you got above.

sudo usbsoftrock -x 114.207544 set freq 14.125
Version     : 15.12

Checking the frequency. sudo usbsoftrock getfreq

Version     : 15.12
Frequency   : 14.089549 (x 4.00)

here is the command list

COMMAND is one of
  calibrate (may require -s option)
  getptt                                 (-h option for Mobo only)
  getkeys                                (PE0FKO+TF3LJ+Mobo)
  ptt {on|off}
  set bpf {on|off}                       (PE0FKO+TF3LJ+Mobo)
  set bpf_addr <band> <filter>           (PE0FKO >= 15.12+Mobo)
  set bpf_point <crossover> <f in MHz>   (PE0FKO+TF3LJ+Mobo)
  set lpf {on|off}                       (TF3LJ+Mobo only)
  set lpf_addr <band> <filter>                   "
  set lpf_point <crossover> <f in MHz>           "
  set freq <frequency in MHz>
  set si570_addr <i2c address in decimal>
  set si570_multiplier [band] <decimal factor>  (PE0FKO>=15.12+Mobo)
  set startup <frequency in MHz>         (PE0FKO+TF3LJ+Mobo)
  set xtall <frequency in MHz>           (PE0FKO+TF3LJ+Mobo)

  where TF3LJ = Lofturs AtMega168 derivative
        Mobo  = Mobo 4.3 Project AT90USB162 Firmware