TWO Amperex ECC82 12AU7 tube

Tubes test 1600, 1700 and 1900, 1600 where pass/fail is 1430 micromhos

One tube is labeled Amperex one tube is labeled RCA, but both tubes made by Amperex

Foil D getters / square foil / angle / slanted D getter

Long plates / 17mm ribbed plates

Made in Holland

Very early production

Tubes made 2 months apart

Δ5K etched date code =

Phillips, Heerlan Holland 1955 November

Δ6B etched date code =

Phillips, Heerlan Holland 1956 February

Tested on Amplitrex AT-1000 computerized tube tester (fixed bias mode)

FULL TEST RESULTS:

Tube 1:

1600 gm / 1700 gm (uMhos)

10.2 mA / 9.2 mA Plate Current Emissions (iP)

NO SHORTS / ZERO GAS

% Test results in percent %

80% / 85% gm (uMhos)

97.1% / 87.6% mA plate current

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Tube 2:

1900 gm / 1600 gm (uMhos)

9.8 mA / 10 mA Plate Current Emissions (iP)

% Test results in percent %

95% / 80% gm (uMhos)

93.3% / 95.2% mA plate current

NO SHORTS / ZERO GAS

USA Shipping free priority / advantage

international shipping = UPS 7 day delivery signature service or Global Post 10-20 day delivery depending on your country

*In photos I use camera flash on and camera flash off to show all detail*