4 x 6BQ5/EL84 Amperex  Matched Tubes

Made in Holland for Hammond

Date codes: rx4

Grey Plates

Large O getters

Tested on a calibrated Hickok 600A

A new 6BQ5 tube tests at approx. 7500 Micromhos

Tubes tested: 7400, 7000, 7250, 7250 Micromhos