National Union

6AK5 JAN

17.00 USD

Rare 1940's production top of the line Mil. Spec. audio pentodes manufactured for the Armed Forces in the United States by National Union. These 7 pin miniature glass amplifiers come with top D getters and black plates. They are printed JNU-6AK5 NATIONAL UNION MADE IN U.S.A. and glass etched 6AK5. Boxes are standard military beige printed U.S. ARMY U.S. NAVY TUBE JNU-6AK5 CONTRACT NO. NXSR-79956 JANUARY 1945.

Condition

New Old Stock (New in box)

	Tube Matching 6.00 USD by tube
LEARN MORE WHY ? A tube may have one, two, or three internal sections depending on the purpose of the tube; somtimes these sections are all the same, sometimes they are different. Due to manufacturing and material tolerances, there may be slight differences between the original specification and the actual tube. Tube matching tests each one of these internal sections and selects tubes, compared to original specifications at manufacture, for balanced performance and good sound. HOW ? All our tubes are tested by us prior to packing on our Stark, AVO, Simpson or RF Laboratories Inc. calibrated testers. On request for tube matching, tubes are matched for Mutual Conductance in Micromhos and Plate Current in Milliamps on our Amplitrex or Radioelec Duovac testers, with results printed for each individual tube. Certain tubes difficult to test are matched for Mutual Conductance in Micromhos only on one of our regular calibrated testers. On request we can also test for Microphonics.