7643
7643 is also designated E80CF. Completed sales put the typical price at $34.50 per tube.
Description
The 7643 is a premium quality, long life, ruggedized triode-pentode with separate cathode leads and a unipotential cathode with parallel supply heater arrangement.
Construction and Ratings
The 7643 has a heater voltage of 6.3 volts and a heater current of 330 mA. It has a shock rating of about 500 g and a vibration rating of 2.5 g. The maximum bulb temperature is 170°C. The maximum cathode to filament voltage is 100 volts, and the maximum negative control grid voltage is 100 volts. The maximum cathode current is 18 mA, and the maximum control grid dissipation is 0.1 watts.
Pentode Section
The pentode section is designed for use as a mixer, RF or AF amplifier. It has a maximum plate voltage of 275 volts and a maximum plate dissipation of 2.15 watts. The maximum screen grid voltage is 200 volts when cathode current is greater than 10 mA, and 225 volts when cathode current is less than 10 mA. The maximum screen grid dissipation is 0.7 watts when plate dissipation is greater than 1.2 watts, and 0.8 watts when plate dissipation is less than 1.2 watts. The maximum control grid resistor is 1 megohm with automatic grid bias and 0.5 megohms with fixed grid bias. The pentode section has an amplification factor (Grid No. 2 to Grid No. 1) of 40, a plate resistance of 0.4 megohms, and an equivalent resistance of 1500 ohms. Typical operating conditions include a plate supply voltage of 170 volts, a screen grid supply voltage of 170 volts, a cathode resistor of 155 ohms, a plate current of 10 mA, a screen grid current of 2.8 mA, and a transconductance of 6200 micromhos. The typical input resistance is 10,000 ohms at 50 Mc/s.
Triode Section
The triode section is designed for use as an oscillator up to 300 Mc/s, multivibrator or blocking oscillator. It has a maximum plate voltage of 275 volts and a maximum plate dissipation of 1.75 watts. The maximum peak grid voltage is 30 volts, the maximum grid dissipation is 0.1 watts, and the maximum peak cathode current is 100 mA. The maximum grid resistor is 0.5 megohms. The triode section has an amplification factor of 18. Typical operating conditions include a plate supply voltage of 100 volts, a cathode resistor of 120 ohms, a plate current of 14 mA, and a transconductance of 5000 micromhos. The Amperex datasheet recommends use of the 7643 triode in a Colpitts type of circuit and not in a Hartley type.
Operating Characteristics
The 7643 will maintain its emission capabilities after long periods of operation under cut-off conditions. The Amperex datasheet gives a maximum pulse duration for the 7643 of 4% of a cycle with a maximum of 0.8 milliseconds.
| Designation | Evidence | Confidence |
|---|---|---|
| E80CF | 43 independent documents | confirmed |
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.
| Measure | Per tube |
|---|---|
| Median | $34.50 |
| Typical range (25th–75th) | $28.33 – $62.25 |
| Most sales (10th–90th) | $27.50 – $64.50 |
| Extremes incl. outliers | $27.50 – $64.50 |
| Completed sales | 9 |
| Brand | Median | Range | Sales |
|---|---|---|---|
| Amperex | $31.32 | $28.33 – $42.09 | 3 |
| Condition | Median | Sales |
|---|---|---|
| NOS | $42.09 | 7 |
Per-tube prices from completed sales, 2026-03-18 to 2026-09-04. Matched pairs and quads are divided out. See the price index for how these move over time.
Original manufacturer datasheets for 7643, hosted by Frank Philipse's Electron Tube Data sheets.
| Manufacturer | Designation | Datasheet |
|---|---|---|
| Amperex | 7643 | PDF (313 KB) |
| Philips | E80CF | PDF (1197 KB) |
| Philips | E80CF | PDF (443 KB) |
| AEG | E80CF | PDF (418 KB) |
| Siemens | E80CF | PDF (384 KB) |
Documents held here and used to write this page.
- E80 CF PHILIPS (filed under E80CF)
- AMPEREX TUBE TYPE 7643