WhitakerAudio AM/FM Stereo Tuner 2012, Assembly & User Manual, Page: 153 / 166

153
AM/FM Stereo Tuner
10.7 6CB6
The 6CB6 is a sharp-cutoff pentode. The 7-pin miniature device is used as an IF amplifier and
other RF functions at frequencies up to about 45 MHz. The terminal arrangement is shown in
Figure 10.13.
Selected tube parameters are listed in Table 10.7.
Table 10.7 Key Parameters of the 6CB6
General Characteristics
Heater (ac/dc) 6.3 V, 0.3 A
Heater-cathode voltage
Peak value ±200 V max.
Average value 100 V max.
Direct interelectrode capacitance (approx.), unshielded
Grid #1 to plate 0.025 pF
Grid #1 to cathode, heater, grid #2, grid #3, and internal
shield elements
6.5 pF
Plate to cathode, heater, grid #2, grid #3, and internal shield
elements
2 pF
Class A
1
Amplifier, Maximum Ratings (Design-Maximum Values)
Plate voltage 330 V
Grid #3 (suppressor grid), positive value 0 V
Grid #2 (screen grid) supply voltage Figure 10.3
Grid #2 (screen grid) voltage 330 V
Grid #1 (control grid) voltage, positive bias value 0V
Plate dissipation 2.3 W
Grid #2 (screen grid) input
For grid # 2 voltages up to 165V 0.55 W
For grid #2 voltages between 165 and 330V Figure 10.3
Characteristics
Plate supply voltage 150 V
Grid #3 Note 1
Grid #2 (screen grid) supply voltage 125 V
Cathode bias resistor 56
Ω
Plate resistance (approx.). 280 k
Ω
Transconductance 8000 μmhos
Plate current 13 mA
Grid #2 (screen grid) current 3.7 mA
Grid #1 voltage (approx.) for:
Figure 10.13 Terminal pinout of the 6CB6.