I don't wish to be difficult, but getting a tube checker is not a good short range idea. The old (and I do mean old) tube checkers that are most often for sale, are only useful to separate the living from the dead (and many fail this criterion). Suggestions to the contrary are misinformed.
1. tube checkers must be calibrated to be of much use in matching
2. tube matching is not an easy or quick art to learn
3. power tube matching requires more than simple transconductance matching, it requires proper loading as well, a facility few, if any, commercial units have. A match of 5% under a realistic load is the usual standard.
1. tube checkers must be calibrated to be of much use in matching
2. tube matching is not an easy or quick art to learn
3. power tube matching requires more than simple transconductance matching, it requires proper loading as well, a facility few, if any, commercial units have. A match of 5% under a realistic load is the usual standard.