1. The BEST-2 SKA pathfinder is composed by 32 receivers. The front ends are installed on the focal lines of 8 cylinders, offering a collecting area of about 1400 m 2. The signal is sent to the receiver room via analogue optical fibre links. Receiver chain (block diagram) IF A/D & Data Proc. LO distributor LO OP. Rx OP. Tx F.E. optical fiber Sync Installed on the focal lines Installed in the receiver room A DDC (Digital Down Converter) block and a Polyphase filter bank (“FFT” block of the FX correlator) has been designed and used to configure a 32 receivers FX correlator (Jason Manley, 2008). The back-end is composed of 8 IBOBs, 16 dual ADC boards (8 bit, 1GSPS) and a BEE2 FPGA cluster (1 Tops/sec).

2. A/D1 AD2 Ibob (Serializer) A/D1 AD2 Ibob (Serializer) RX1 RX2 RX n-1 RXn Dual 1GS/sec @ 8 bit Infiniband CX4 Cables FPGA 1 FPGA 2 FPGA-3 FPGA-4 FPGA-5 Bee 2 5x Xilinx Virtex-2 Pro 70 Back End

3. The main features of BEST-2 System temperature: 86 K RF Central frequency: 408 MHz Frequency BW: 16 MHz IF: 30 MHz Instantaneous BW: 16 MHz Instantaneous primary FOV: 37.62 deg 2 FOV-Declination: 5.7 deg FOV-Right ascension: 6.6 deg Synthesized beam size: 0.9 deg 2 Declination: 31.1 arcmin Right ascension: 104 arcmin Independent beams within FOV: 21 Continuum sensitivity BW: 16 MHz Integration Time: 30 sec Total power mode (full array) RMS noise / Sensitivity: 5.4 mJy RMS noise / Sensitivity: 2.0 mK Correlation (full array) RMS noise / Sensitivity: 43.3 mJy RMS noise / Sensitivity: 2.8 mK IF, data acquisition and processing blocks for BEST

4. Possible hardware/scientific tests with the BEST-2 system (in collaboration with Oxford University): 1.Multibeaming capability (tracking of a Pulsar pair in the FOV) 2.Testing post-processing hardware and algorithms (survey for dispersed transient signals of astrophysical origin) (see SKADS newsletter #5, May 2009)