(RCA HB-3 data courtesy Paul Bigelow and John Shriver)
RCA Tenative Data June 20, 1946
26A6 RF-AMPLIFIER PENTODE
Miniature Remote Cutoff Type
GENERAL DATA
Electrical:
Heater, for Unipotential Cathode:
Voltage.............. 26.5 ac or dc volts
Current.............. 0.07 amp
Direct interelectrode Capacitance:*
Grid #1 to Plate .0035 max uuf
Input 6.0 uuf
Output 5.0 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........7BK1
Pin Electrode
1 Grid #1
2 Grid #3, internal shield
3 Heater
4 Heater
5 Plate
6 Grid #2
7 Cathode
CLASS A1 AMPLIFIER
Maximum Ratings, Design-Center Values:
PLATE VOLTAGE.......................... 250 max volts
GRIDS No. 2 (SCREEN) VOLTAGE........... 100 max volts
GRIDS No. 2 SUPPLY VOLTAGE............. 300 max volts
PLATE DISSIPATION...................... 3.0 max watt
GRIDS No. 2 DISSIPATION................ 0.4 max watt
TOTAL CATHODE CURRENT.................. 14 max ma
GRID No. 1 (CONTROL GRID) VOLTAGE:
Negative bias value................. 50 max volts
Positive bias value................. 0 max volts
PEAK HEATER-CATHODE VOLTAGE:
Heater negative w.r.t cathode....... 90 max volts
Heater positive w.r.t cathode....... 90 max volts
Typical Operation and Characteristics:
Plate Voltage 26.5 250 volts
Grid #3 (suppressor) connected to cathode at socket
Grid #2 26.5 100 volts
Grid #1 Voltage:
from grid #1 resistor 2 megohms
from cathode resistor 125 ohms
Plate Resistance 0.25 1.0 megohm
Transconductance 2000 4000 umhos
Grid #1 bias for
transconductance of
40 umhos -25 volts
Grid #1 bias for
transconductance of
20 umhos -8 volts
Plate Current 1.7 10.5 ma
Grid #2 Current 0.7 4.0 ma
Average Plate Characteristics 0-80 volts
Average Plate Characteristics 0-400 volts
