All of these tubes have been tested for transconductance, shorts, gas, leakage and life. These tubes have black ladder plates and halo getters. They have 1960 and 1961 date codes. They have been tested for shorts, gas, and transconductance.
All of these tubes have been tested for transconductance, shorts, gas, leakage and life. These tubes have black ladder plates and halo getters. They have 1960 and 1961 date codes. They have been tested for shorts, gas, and transconductance.