14A7

14A7 is also designated 12B7.

The 14A7 is a pentode voltage amplifier of lock-in construction, intended for RF or IF service in AC/DC receivers. It has a glass bulb and a coated unipotential cathode, and may be used in any mounting position.

Construction

The 14A7 uses a lock-in 8-pin base and has no top cap. The Tung-Sol datasheet lists the bulb as T-9, with a maximum diameter of 1 3/16 inches, a maximum overall length of 2 25/32 inches, and a maximum seated height of 2 1/4 inches. Pin connections are: pin 1 heater, pin 2 plate, pin 3 grid 2, pin 4 grid 3, pin 5 internal shield, pin 6 grid 1, pin 7 cathode, and pin 8 heater. The heater is rated at 12.6 volts and 150 mA, AC or DC.

Ratings

The Tung-Sol datasheet lists maximum plate voltage as 300 volts, maximum grid #2 voltage as 125 volts, and maximum grid #2 supply voltage as 300 volts. Maximum plate dissipation is 4 watts, and maximum grid #2 dissipation is 0.4 watt. Maximum heater-cathode voltage is 90 volts.

Characteristics

At a plate voltage of 250 volts and a screen voltage of 100 volts, the Tung-Sol datasheet gives a transconductance of 2000 μmhos, a zero-signal plate current of 9.2 mA, a zero-signal screen current of 2.4 mA, and a plate resistance of approximately 0.8 megohm. The control grid voltage for a transconductance of 10 μmhos is -35 volts. Interelectrode capacitances are listed as 5.5 μμf for control grid to cathode, 7.0 μμf for plate to cathode, and 0.005 μμf maximum for grid to plate with an external shield connected to cathode.

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 14A7, hosted by Frank Philipse's Electron Tube Data sheets.

Documents held here and used to write this page.

• - TUNG-SOL - (filed under 12B7)
• 14A7/12A7 (7A7)