We at NRAO have been working in parallel on two pulsar designs for the roach. We've gotten a 2048 channel, full stokes, version of the Parspec design to fit on the Roach and stream data sampled at 1 GHz. This design has 500 MHz bandwidth. The band pass looks reasonable, but there are still some logic problems with shuffling the data into the 10 GbE port.
We've also built a 2048 channel version of our "GUPPI" design pulsar back end, which fits. But again, there are some logic issues we're tracking down. The Guppi design is aimed at 800 MHz double clocked samples, so has a bandwidth of 800 MHz. So we're close, but have not fully succeeded in getting either design to stream data. Note that the receive side software appears to be working, as it will be similar to the system we use for the GUPPI pulsar backend. Good Luck (and wish us some). Glen > Hi everyone, > > Does anyone have a sense of whether a dual polarization, 800 MHz > spectrometer with ~2k channels would fit into a ROACH? I have a test > design using the ADC083000 and and two small wideband FFTs. It seems > to work in terms of utilization, but I get a crazy number of timing > errors. > Has anyone successfully built anything like this? > > Thanks, > Laura >
