The advice involved how to set the instrument to test three tubes not listed in the manual available to my friend. The tubes were**a**6EA8 (use the settings for a 6U8), a 5670 (2C10) , and a 26Z5W (try a lower voltage #Z5 or #Z5W). -- *Ron Hunsicker** **1238 Cleveland Avenue** **Wyomissing, PA 19610-2102** **610.478.0371** **ronhunsi at ptd dot net** *