From morse@phys.hawaii.edu Tue Jun 1 12:08:47 2010 Date: Tue, 1 Jun 2010 12:08:46 -1000 (HST) From: Bob Morse To: Michael Duvernois Cc: Peter Gorham , Gary S. Varner , Bob Morse , Matt Newcomb Subject: Re: Couple of quick ARA/Test Bed questions Hi Mike, a couple of partial answers, on the cable stuff. at one cable end the 12 wires are terminated in a single 16-pin (11 + 5) screw-type connector, and at the other end the 3 quads are each separately terminated in 3 5-pin screw-type connectors. I will have to research exactly what type of connectors they are...manufacturer? Check with Peter to see if these will get changed out or if they will survive? the power and signals for the DOM-MB (+/-48 volts is on one pair of the 6 pairs, just like IceCube. the other 5 pair are run in parallel to provide about 60 watts at about 100 volts to the electronics. each wire in a pair is about 1.8 km long and has about 50 ohms. That means the total parallel loop resistance is about 20 ohms. (see comment ***** below) At 60 watts, we pull about 0.6 amps at 100 volts, so that the voltage drop is about 0.6 X 20 = 12 volts. for full details...see the writeup I sent you in the 1.8 km cable document. *****i mentioned to Matt that maybe we want to only use 4 pairs for power and use the 5th pair to monitor the voltage actually being delivered to the testbed using a high-impedance voltmeter in the ICL. Peter will probably get back with you as to the number of antennas, etc... Cheers...Bob MOrse Robert M. Morse tel: 808-956-7051, cell: 808-927-1785, FAX: 808-956-2930 Physics Dept. Univ of Hawaii, 2505 Correa Rd, Honolulu, HI 96822, USA , 1. What's the pinout on the testbed end of the Ericsson cable? I'm > remembering power on all of the pairs, is that right? > > 2. How many inputs are on the system? How many LNAs? Six in-ice antennas > and two surface antennas, is that right? > > Thanks! > Mike >