There are 2 options.
1. Use a tester, but some only give you a good-bad decision, no idea of how good. Its been a long time since they've been at the five and dime (a long time since there has even been a five and dime), but you may find one at your local independent hi-fi or tv repairman, or if you post your location, someone here may volunteer.
2. Sub them in to a component that uses the same tube type, but again, that will only give you a go-no go decision
1. Use a tester, but some only give you a good-bad decision, no idea of how good. Its been a long time since they've been at the five and dime (a long time since there has even been a five and dime), but you may find one at your local independent hi-fi or tv repairman, or if you post your location, someone here may volunteer.
2. Sub them in to a component that uses the same tube type, but again, that will only give you a go-no go decision