On November 25th 2008, an important milestone of the WideX development has been reached. A complete signal chain including two samplers boards, one correlator board and one readout/clock board have been successfully operated together. The sampler board includes a 4 GHz sampling head, a demultiplexer and a format/delay system. The correlator board includes 28 correlator ASIC's of 2048 channels each. The readout board provides clock and timing signals for the whole system and manages data transmission to and from the computer, which runs a user friendly test software interface.
The screen snapshot in Fig. 6 shows the cross-correlation function of two analog copies of a 2-4 GHz noise source, which was deliberately filtered to a 350 MHz width in order to spread the pattern over several channels. The peak appears on channel 1015 instead of 1023, (250 picosecond per channel) due to deliberately using non-equal analog cables. The total delay range is 16.384 microseconds, which corresponds to km from the array phase center.