• High-Voltage Tested at 550 V

    Unlike a simple emission or low-voltage tube test, these EL34/6CA7 tubes are measured at a plate voltage of 550 V.

    Test conditions:
    Ua = 550 V · Ug2 = 300 V · Ug1 = −25 V

    Both plate current (Ia) and transconductance (Gm/S) are measured.
    Matched pairs are selected for close agreement of both values under exactly the same high-voltage test conditions.


    • GE 6CA7 EL34 — MATCHED PAIR
    CONDITION & IDENTIFICATION
    Condition barely used
    Original print Perfect, fully preserved
    Getter Twin Disc Getter 
    TEST RESULTS & MATCHING
    RoeTest V11
    Parameter Tube 1 Tube 2 Datasheet (100%)
    Ia – Anode Current 27.0mA 29,0 mA 30.0 mA
    Gm – Transconductance 4,740 µmhos 4,900 µmhos 5,000 µmhos
    Manufacturer Tolerance (Datasheet)    Ia:   |   Gm:


    Ia = Anode current:
    This value indicates the anode current at the specified operating point. A deviation from 100% does not by itself indicate a weak or worn tube. Ia alone provides no reliable information about remaining service life.