6J6
6J6 is also designated ECC91. Completed sales put the typical price at $4.95 per tube.
Description
The 6J6 is a miniature medium-mu twin triode. It is designed for use as a radio-frequency amplifier, oscillator, or mixer. The tube has a coated unipotential cathode and a T-5½ glass envelope with an E7-1 miniature button 7-pin base. It can be mounted in any position.
Construction
The 6J6 operates with a heater voltage of 6.3 volts AC or DC and a heater current of 0.45 amperes. The pinout is: pin 1 is plate (section 2), pin 2 is plate (section 1), pin 3 is heater, pin 4 is heater, pin 5 is grid (section 1), pin 6 is grid (section 2), and pin 7 is cathode.
Ratings and Characteristics
The 6J6 has an amplification factor of 38, a plate resistance of approximately 7100 ohms, a transconductance of 5300 micromhos, and a plate current of 15 milliamperes per section. Direct interelectrode capacitances, measured without a shield, are: grid to plate, each section, 1.6 μμf; input, each section, 2.2 μμf; and output, each section, 0.4 μμf.
Maximum ratings include a plate voltage of 300 volts, a plate dissipation of 2x1.5 watts, a grid voltage of -40 volts, a grid current of 2x8 milliamperes, a heater-cathode voltage of 100 volts, and a grid resistance of 0.5 megohms with self bias.
Applications
With the grids connected in push-pull and the plates connected in parallel, the 6J6 may be used as a mixer at frequencies as high as 600 megacycles. In class C telegraphy push-pull RF amplifier and oscillator operation at 80 Mc/s, typical operating conditions include a plate voltage of 150 volts, a grid voltage of -10 volts, a plate current of 2x15 milliamperes, a grid current of 2x8 milliamperes, a grid driving power of 0.35 watts, and a power output of 3.5 watts. An output of approximately 1.0 watt can be obtained when the 6J6 is operated as a push-pull oscillator at 250 megacycles with a plate voltage of 150 volts.
| Designation | Evidence | Confidence |
|---|---|---|
| ECC91 | 46 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 | $4.95 |
| Typical range (25th–75th) | $2.84 – $10.15 |
| Most sales (10th–90th) | $1.34 – $22.69 |
| Extremes incl. outliers | $1.11 – $33.09 |
| Completed sales | 24 |
| Brand | Median | Range | Sales |
|---|---|---|---|
| GE | $3.30 | $3.00 – $8.90 | 5 |
| RCA | $4.34 | $2.78 – $6.60 | 4 |
| Condition | Median | Sales |
|---|---|---|
| NOS | $5.90 | 21 |
Per-tube prices from completed sales, 2026-06-27 to 2026-09-18. Matched pairs and quads are divided out. See the price index for how these move over time.
Original manufacturer datasheets for 6J6, hosted by Frank Philipse's Electron Tube Data sheets.
| Manufacturer | Designation | Datasheet |
|---|---|---|
| General Electric | 6J6 | PDF (366 KB) |
| Tung-Sol | 6J6 | PDF (137 KB) |
| Brimar | 6J6 | PDF (97 KB) |
| Mullard | ECC91 | PDF (152 KB) |
| RFT | ECC91 | PDF (102 KB) |
| Philips | ECC91 | PDF (37 KB) |
Documents held here and used to write this page.
- 6J6—5J6—19J6 TWIN TRIODE
- ECC91 (filed under ECC91)
5 further designations appear alongside 6J6 in the literature but below the evidence threshold used here, so they are not listed as equivalent.