Had an electronic repair shop test 2 pairs of Sylvania 5751JHS with grayplates,O-getter, triple mica spacers, all with 6638 date codes, on a Hickok 539c.
One pair measured a respectable 1410/1400gm and 1400/1490gm.
The other pair measured 1600/1600gm and 1600/1680gm.
Can this be correct?
