NOS EL84 6BQ5 tube Philips Miniwatt etched codes rX4 ⊿1B4 from 1961

Pristine tube recently acquired from an engineer's estate who was in their late 80's. There was a handful of new old stock tubes that were tucked away in the basement untouched for 50+ years. With confidence, I can say this tube was never placed in use as you do not see any of the brown burned glass that is typical inside of EL84/6BQ5 tube. The tube is pristine as well as the white font printing as well.

Date code: rX4 ⊿1B4 from 1961 Heerlen factory

Tested at 11000 uM micromhos on a restored/calibrated Hickok 539B tube tester,

The minimum acceptable values is 5650 uM microhmos on the Hickok tester.

Please note test values may differ slightly from tester to tester and not responsible if your tester reads it differently and/or slightly different values than shown here. Values are added as a means to show the tubes indeed test strong/new, not an exact science. Your results can/may vary.