Two, RCA 6L6GC, with the tubular, domed glass envelope. Tested on a Hickok TV-3 military tester that has been calibrated. Firm bases, black plates. Tubes are matched for dynamic gain and structure- test at 5000, 5000 where pass/fail is 3150 micromho. The tubes have the same structure inside and out. The tubes were also matched on a "Maximatcher", at fixed bias, having plate currents of 21.0 ma and 20.7 ma.  Do not compare these currents to a Hickok 539 results, as the plate voltages and bias' are completely different- the Maximatcher tests at full plate voltage and a fixed grid bias that is representative at actual use.  The tubes have the same structure inside and out, having date codes. "DA" and "BH", August 1970 and November 1966.  

Many other lots of tubes for sale this week.