The LBCF has 4 independent DAQ stations NE,NW,SE,SW in each geographical corner of the Soudan 2 cavern at Soudan. Each station has two or three front-end electronics multiplexer (MUX) boards. The expected relative timing resolution of < 4us for our 1kHz GPS carrier, had been observed as of June 4th 2013 on only one station-mux-combination pair. The pair which showed the good timing was SE MUX 2, to SW MUX 2. The correlated timing was confirmed using a 40 Hz pulser which supplied simultaneous pulses to both of the station/mux combinations. The last week in June 2013 was deticated to examining this problem in detail with Kelly Stifter at Soudan, setting up various timing tests.

Several kinds of tests were used to diagnose the problem, a summary table of the tests is given below.