Gain Notes for Revolution 420
	
JEM-X1: See notes for revolution 410. This is another SCO X-1 revolution where
gain calibration has gone slightly awry thanks to a strong target source and
a very weak calibration source. As described in the revolution 410 notes, this
problem can be fixed by downloading and IC Gain History table from ISDC as
part of their instrument model package, or by downloading the table provided
with these notes in the Gain History Archive.

The Xe line analysis performed using the offline Gain History tables described
above, shows that the gain correction has performed very well except at the
beginning of the revolution, which is quite normal. The average Xe position
is within 1% of the expected value which is good. 

JEM-X2: No scientific data or gain history data for this unit.

CAO 30/8/2007