5965
5965 has no equivalent designation confirmed by the archive. Completed sales put the typical price at $11.56 per tube.
The 5965 is a dual-unit vacuum tube intended for computer service, with each unit consisting of a triode; the datasheet gives average plate characteristics for each unit.
Construction
The 5965 uses a small-button Noval 9-pin base (JETEC No. E9-1) with a basing designation of 9A for bottom view. Pin 1 is the plate of unit No. 2, pin 2 is the grid of unit No. 2, and pin 3 is the cathode of unit No. 2. Pins 4 and 9 serve as the heater for unit No. 2, while pins 5 and 9 serve as the heater for unit No. 1. The bulb is of the small-button Noval 9-pin type. Maximum overall length is 2-3/16 inches without an external shield and 1-15/16 inches with an external shield; length from base seat to bulb top (excluding tip) is 1-9/16 inches ± 3/32 inch. Maximum diameter is 7/8 inch.
Ratings
The heater can be operated with 12.6 volts ac or dc when the heater sections are series connected. Maximum plate voltage is 150 volts for negative bias operation. Maximum plate dissipation is 2.4 watts per unit, with a maximum total plate dissipation of 4.4 watts for both units. Maximum heater-cathode voltage is 200 volts with the heater either negative or positive with respect to the cathode. Maximum grid-circuit resistance is 0.1 megohm for fixed-bias operation and 0.5 megohm for cathode-bias operation. Maximum bulb temperature at the hottest point on the bulb surface is 165 °C.
Characteristics
Transconductance per unit is between 5100 and 7900 μmhos, and amplification factor per unit is between 39 and 55; both are measured with a plate supply voltage of 150 volts and a cathode resistor of 220 ohms adequately bypassed for a signal frequency of 60 cps. Plate current per unit is between 6 and 10.4 milliamperes. Heater-cathode leakage current is a maximum of 20 μamp with the heater either negative or positive with respect to the cathode. Reverse grid current is a maximum of 1 μamp per unit.
Typical Operation
In typical computer service, the 5965 operates with a plate supply voltage of 150 volts and a plate load resistor of 7200 ohms, yielding a plate current of 10.5 mA in the conducting condition. The datasheet, dated March 4, 1954, is marked as tentative data.
| Measure | Per tube |
|---|---|
| Median | $11.56 |
| Typical range (25th–75th) | $5.18 – $36.80 |
| Most sales (10th–90th) | $3.25 – $71.40 |
| Extremes incl. outliers | $2.70 – $89.85 |
| Completed sales | 26 |
| Brand | Median | Range | Sales |
|---|---|---|---|
| GE | $7.79 | $5.00 – $13.22 | 14 |
| RCA | $5.80 | $4.06 – $8.73 | 5 |
| Mullard | $36.80 | $36.80 – $63.56 | 3 |
| Condition | Median | Sales |
|---|---|---|
| NOS | $18.37 | 12 |
| used | $6.54 | 8 |
Per-tube prices from completed sales, 2026-06-20 to 2026-09-12. Matched pairs and quads are divided out. See the price index for how these move over time.
Original manufacturer datasheets for 5965, hosted by Frank Philipse's Electron Tube Data sheets.
| Manufacturer | Designation | Datasheet |
|---|---|---|
| RCA (HB3) | 5965 | PDF (389 KB) |
| Sylvania | 5965 | PDF (362 KB) |
| Brimar | 5965 | PDF (188 KB) |
Documents held here and used to write this page.
- AVERAGE PLATE CHARACTERISTICS FOR EACH UNIT