DEAD AND NOISY CHANNEL SUMMARY R. D. Cohen, D. S. Tudbope, E. A. Beaver Univeriit~ of California, San Diego Instrument Science Report CAL/FOS-051 April, 1989 1. Introduction Severa.l sets of dirk exposures, with the voltage either on or off were taken after the installation and calibration of the FOS detectors in February a.nd March 1988. These include one set taken specificaliy to test some proposed discriminator changes. Based primarily on these tests, we make recommendations on an initial list of channels to disable during FOS operations. We emphasize tba.t the current set of disabled cha.nnels and discriminator settings ii not correct as im.