Two National Union type 45 tubes

Tubes test 2680 and 2600 where 1300 micromhos is pass/fail

Made in USA year 1937

Original boxes included. This is early type N.U. Box with early type graphics and logos

Hanging filaments

Black plate

Identical internal construction

Extra mica supports on sides

Foil getters

No rattle / no loose parts / tight bases

Clean shiny pins

Matched AN date codes on boxes and bases

Date codes AN = year 1937 week 28 (July)

NO SHORTS / NO GAS

Strong +100 gm and mA test results

FULL TEST RESULTS :

-Tube #1= 2680 micromhos and 47.4 mA plate current

-Tube #2= 2600 micromhos and 41.8 mA plate current

% Test results in percent %

134% / 130% Gm mutual condunctance

131.6% / 116.1% mA plate current

For reference:

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

For reference:

Type 45 tubes: Spec (new) = 2000 micromhos and 36 mA plate current

Type 45 tubes: 1300 micromhos and 23.4 mA = pass/fail grade (65% of Spec value)

* I take photos with camera flash and also no camera flash to show all detail

USA = usps priority or ground advantage

International = UPS FedEx 7-10 day delivery signature delivery