PCC88

PCC88 is also designated 7DJ8.

The PCC88 is a high-frequency double triode with high transconductance and low noise, intended for input circuits of television receivers. It has an all-glass miniature envelope with a nine-pin base, and the two systems are shielded from each other by an internal shield connected to a separate base pin. The tube has indirect heating with an oxide cathode, designed for series supply with AC or DC current.

Construction

The PCC88 uses a base of type S 9/12 per ČSN 35 8904, and its maximum weight is 12 g. The datasheet specifies a heater voltage of 7 V and a heater current of 0.3 A. The two triode systems are intended to be used together, with system I as a grounded-cathode amplifier and system II as a grounded-grid amplifier.

Ratings

Maximum ratings for the PCC88 include a cold anode voltage of 550 V, an operating anode voltage of 130 V, an anode dissipation of 1.8 W, a cathode current of 25 mA, a negative grid voltage of 100 V, a grid dissipation of 0.03 W, a grid circuit resistance of 1 MΩ, an effective cathode-to-heater voltage of 80 V, and an external cathode-to-heater resistance of 20 kΩ.

Typical Operating Conditions

Typical operating conditions are given at an anode voltage of 90 V, with a grid bias of -1.3 V, an anode current of 15 mA, a transconductance of 12.5 mA/V, an amplification factor of 33, and an internal resistance of about 2.6 kΩ. The cutoff anode current at a grid voltage of -4 V is less than 1.2 mA.

Capacitances

For system I, the interelectrode capacitances are: anode to cathode, heater and shield 1.8 pF; grid to cathode, heater and shield 3.3 pF; anode to grid 1.4 pF; and grid to heater less than 0.2 pF. For system II, the capacitances are: anode to grid 1.4 pF; grid to heater less than 0.2 pF; anode to grid, heater and shield 2.8 pF; cathode to grid, heater and shield 6 pF; anode to grid less than 1.8 pF; anode to cathode 0.18 pF; and cathode to heater less than 3.5 pF. The capacitance between anode I and anode II is less than 0.045 pF, and between grid I and anode II is less than 0.005 pF.

Application Notes

The datasheet notes that to not exceed the maximum permissible plate voltage when the cascode amplifier is controlled, a voltage divider for the grid of the grounded-grid section is necessary. With grid current biasing for the grounded-cathode section, the plate voltage across this section should not exceed 75 volts in the not-controlled condition.

Equivalence is asserted only where the archive's own literature states it directly, in at least 40 separate documents. Tubes that merely substitute in some circuits are not listed here.

Original manufacturer datasheets for PCC88, hosted by Frank Philipse's Electron Tube Data sheets.

Documents held here and used to write this page.

• 7DJ8 (filed under 7DJ8)
• VYSOKOFREKVENČNÍ DVOJITÁ TRIODA