Many tubes will test "weak" if they are not tested properly. Two things to remember when testing tubes: 1.) Make sure the tube tester has a line voltage adjustment so that you can have an accurate reference point. 2.) Most important!!! Let the tube warm up for at least 5 minutes!!!!! I had the same experience. When I found a good tube tester that had a line voltage adj. (That worked) and let the same tubes that tested "weak" on another tester, warm up for 5 min. and retested THEY ALL TESTED GOOD-VERY GOOD!!!!
