JPL digital backend


160617: Using a transmitted xband tone to check the backend
160922: Using a transmitted xband tone to check the backend
161027: variable attenuators added
161027: Testing the linearity of the system.
JPL operating manual (.doc) (internal access only)


    The jpl backend is an voltage recording system assembled by jpl and located in the  computer room. It is mainly used for planetary radar   xband,cband  experiments (where jpl transmits, and AO receives).
    Some basic info

Variable attenuators:

     Variable attenuators were added(161025)  after the IF filters, before the amp in the jpl rack.

160817:xband tone to check backend

    An xband tone transmitted from the control room was recorded (through the xband receiver) on the jpl backend.

The setup was:

 Processing the data:

The plots show the results of the measurement (.ps)  (.pdf)


Notes on doing the tone experiment:


160922: xband tone to check digital receiver.

    Clement modified the fpga code to support IF's of 260 and 325 MHz. On 22sep16 i rechecked the system by generating an xband tone and receiving with the xband receiver. It was then passed to the jpl digital receiver.

    The setup was similar to that of 160817 (see above)
     10 second of data was written to data20160922130808.000 and then xfered to an AO machine

The plots show the rms, histogram, and averaged spectra with the 8651 MHz tone (.ps) (.pdf)

processing: x101/160922/

161027: testing the backend linearity

    The variable attenuators were used to test the linearity of the digital backend. The setup was:

The plots show the measured power vs the attenuation (.ps) (.pdf):


processing: x101/161027/

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