Matched Pair RCA 6K6 6K6GT Vacuum Tubes Valves October 17 2025 These tubes have acid-etched codes

These tubes have acid-etched codes and designations as well as silk-screened 68-26 188-5 67-50 production run/provenance codes

I just cleaned this LP on my VPI 16

It is a bit microphonic

new in box GE 12AX4 tubes tested to spec on our Paul Hart-calibrated TV7/U

They have double O getters

Matched Pair RCA 6K6 6K6GT Vacuum Tubes Valves October 17 2025 These tubes have acid-etched codesThis matched pair of RCA MANUFACTURED 6K6GT tubes was tested on our Maxi Matcher 400 volts on the plates and a bias of 36 volts for shorts, gas and transconductance. There were no shorts or gas. Tube One drew 21. 6 milliamps' plate current and measured 1610 micromhos. Tube Two measured 25 1860. New nominal is within one standard deviation of 1900. These tubes have black plates; copper support rods; rectangular mica spacers and gapped D getters. As I