Philips

12DW7 / 7247

49.00 USD

Top of the line dissimilar double triode tubes manufactured in the United States by Philips. These fine 9 pin miniature glass tubes, designed for voltage amplifier and phase inverter srvice, come with gray plates and top halo getters. They are glass etched 12DW7 USA, and printed in blue PHILIPS ECG MADE IN USA. Boxes are standard Philips yellow printed 12DW7.

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.