(RCA HB-3 data courtesy Paul Bigelow and John Shriver)

RCA Tenative Data                        June 20, 1946

                26C6 DUPLEX DIODE TRIODE

                GENERAL DATA

Electrical:

Heater, for Unipotential Cathode:
   Voltage.............. 26.5  ac or dc volts
   Current.............. 0.07  amp
Direct interelectrode Capacitance:*
   Grid to Plate                      2.0  uuf
   Grid to Cathode & Heater           1.8  uuf
   Plate to Cathode & Heater          1.4  uuf
* with external shield connected to cathode

Mechanical:

Mounting Position............. Any
Maximum Overall Length         2-1/8"
Maximum Seated Length          1-7/8"
Length from Base Seat to
   Bulb Top (excluding tip)    1-1/2" +/- 3/32"
Maximum Diameter               3/4"
Bulb                           T-5-1/2
Base                           Miniature Button 7-Pin
   Basing Designation for BOTTOM VIEW........7BT
   Pin    Electrode
    1     Triode Grid
    2     Cathode
    3     Heater
    4     Heater
    5     Diode Plate No. 2
    6     Diode Plate No. 1
    7     Triode Plate

        TRIODE UNIT - Class A1 AMPLIFIER

Maximum Ratings, Design-Center Values:
PLATE VOLTAGE.......................... 250 max volts
PLATE DISSIPATION...................... 2.5 max watt
PEAK HEATER-CATHODE VOLTAGE:
   Heater negative w.r.t cathode....... 90 max volts
   Heater positive w.r.t cathode....... 90 max volts

Characteristics
Plate Voltage           26.5    250     volts
Grid Voltage:
  from fixed supply     ----    -9      volts
  from grid resistor    2.0             megohms
Amplification Factor    17      16
Plate Resistance        15.5K   8.5K    ohms
Transconductance        1100    1900    umhos
Plate Current           1.1     9.5     ma

Typical Operation with Resistance Coupling:
See RESISTANCE-COUPLED AMPLIFIER CHART, Type 6R7

        DIODE UNITS -- Two

   The two diode plates are placed around a cathode, the
sleeve of which is common to the triode unit.  Each diode
plate has its own base pin.  Diode curves in the front
of the RECEIVING TUBE SECTION apply to the 26C6.

        Additional curves applying to the 26C6
        are shown under Types 6R7 and 6SR7.

26C6 Characteristic Curves

Average Plate Characteristics