After trying several pairs of 6JB6 tubes with similar behavior ( PA current very sensitive to drive control position), concluded the trouble couldn't be the PA tubes. Swapped the driver tube with one in my T-4XB, now the plate current behaves normally, that is increases smoothly with increasing drive rather than jumping sharply from about 150 ma to 250 ma.
I haven't checked to see whether the T-4XB now behaves strangely using the driver from the T-4X , and the driver tests good in my old Eico tube tester. But, have always heard that a tube testing good in a simple emmission tester doesn't mean it will work properly in circuit. Any thoughts? 73, Curt KB5JO _______________________________________________ Drakelist mailing list [email protected] http://mailman.zerobeat.net/mailman/listinfo/drakelist
