I sent some tubes off to my tech to be tested, and his Hickok tester wasn't able to test a couple of the bigger boys, so he tested them with a calibrated lab grade HT supply and bench DC supply. So, I'd like to sell these tubes, but everyone on fleabay seems to want a Hickok score/number. I don't know what these values would roughly correlate to. Can anyone help me make some sense of this? I've attached original datasheets for both tubes. Thanks a ton!
Notes from tech:
Tested HT supply - OK 0 to +400V, 0 to -125V. Set up test on 262A. +10V on heater, draws 0.31A per specification. Heater glow observed. Set up test with B+ via 100k resistor at 135V, C- via 2.2k resistor at -12V to -0.5V, ammeter to monitor plate current shows variation in current. Need to test further.
Tested 262B: Calculated load line, set Ebias = -4.0, HT = 135V, Rp = 20kΩ, Rl = 39kΩ, Rg = 100kΩ, coupling = 0.1/300. Heater = +10V. Input signal 0.68Vrms = 1.9Vpp. Output = 4.06Vrms. Gain = 15.5dB.
Tested 310A: Tested with +10V on heater, draws 310mA per spec. Set up test: HT = 160V, Rp = 47kΩ, Rg2 = 330kΩ, Cg2 = 0.22µF, resultant Vg2 = 83V, Rk = Rg3 = 1.82kΩ, Ck = 47µF, Rg1 = 1.0MΩ, coupling = 0.1/300. Input = 0.35Vrms, Vout = 16.5Vrms. Gain = 33dB.
Notes from tech:
Tested HT supply - OK 0 to +400V, 0 to -125V. Set up test on 262A. +10V on heater, draws 0.31A per specification. Heater glow observed. Set up test with B+ via 100k resistor at 135V, C- via 2.2k resistor at -12V to -0.5V, ammeter to monitor plate current shows variation in current. Need to test further.
Tested 262B: Calculated load line, set Ebias = -4.0, HT = 135V, Rp = 20kΩ, Rl = 39kΩ, Rg = 100kΩ, coupling = 0.1/300. Heater = +10V. Input signal 0.68Vrms = 1.9Vpp. Output = 4.06Vrms. Gain = 15.5dB.
Tested 310A: Tested with +10V on heater, draws 310mA per spec. Set up test: HT = 160V, Rp = 47kΩ, Rg2 = 330kΩ, Cg2 = 0.22µF, resultant Vg2 = 83V, Rk = Rg3 = 1.82kΩ, Ck = 47µF, Rg1 = 1.0MΩ, coupling = 0.1/300. Input = 0.35Vrms, Vout = 16.5Vrms. Gain = 33dB.