| We present two new filterbank spectrometers designed specifically for pulsar timing and surveys with large to medium sized radio telescopes. The Penn State Pulsar Machine (PSPM) is a 2 x 128 x 60 kHz filterbank designed for observations at intermediate radio frequencies around 400 MHz and is currently installed at Arecibo Observatory in Puerto Rico. The Penn State Pulsar Machine II (PSPMII) is a 2 x 64 x 3 MHz filterbank built for observing pulsars at frequencies above 1 GHz with the 32 meter radiotelescope in Torun, Poland. The control software developed for the new filterbanks incorporates a graphical interface which can be run over the Internet for monitoring and remote control of observations.; Our drift survey of 2000 deg{dollar}sp2{dollar} of the sky with the PSPM at Arecibo is the first of its kind to achieve {dollar}sim{dollar}1 mJy sensitivity to pulsars with periods shorter than 1 ms. Theory predicts that a neutron star will begin to shed mass at rotation periods less than about 0.5 ms. The discovery of a pulsar rotating with a period less than a millisecond will help constrain neutron star equations of state. To date, the Penn State surveys at Arecibo have discovered a 4.6 millisecond pulsar, PSR J1709+23, that appears to be in a low mass binary system with a 22.7 day orbital period, and the young pulsar, PSR J0538+2817, possibly associated with the supernova remnant S147 located in the direction of the Galactic anticenter.; Calibration timing observations with the PSPM typically show factor of two improvement in timing accuracy for low-DM millisecond pulsars like PSR B1257+12 and PSR B1640+22, as compared to the previous most sensitive pulsar timing backend at Arecibo. Our timing observations of PSR B0329+54 with the PSPMII clearly disprove the existence of a planetary companion with a 16.8 year orbit, recently proposed for that pulsar. |
