8056
The 8056 (P/N 154-0417-00) is a low-voltage Nuvistor triode vacuum tube with a 6.3 V heater.
It is used in the 422, 502, early W, 1S1, 3A7, early 3S3, 3T4, 5T3, and 10A1. It can sometimes be replaced with a MPF102 FET.
The 8056 has a maximum plate-to-cathode voltage of 50 V. Contrast this with another Nuvistor triode, the 7586, which has a maximum plate-to-cathode voltage of 110 V (however, one of the 8056 test conditions for 157-0099-00 puts 100 V on the plate.)
The 7586 and 8056 have the same pinout, but the two tubes are not interchangeable since they have different voltage ratings.
For example, in the front-end cathode followers of the 3A1, the plate voltage of the 7586 tubes, V113 and V123, is 55 V, and possibly a bit higher during warm-up. This exceeds the maximum plate voltage of the 8056, unless the 3A1 is modified for lower front-end plate voltages.
| Aged/Checked/Matched Pair Details | ||
|---|---|---|
| Used in | Tek Part# | S/N Range |
| 502, W, 3A7, 10A1 | 157-0099-00 | All |
Reference:
Links
Some instruments using part 8056
| Instrument | Manufacturer | Class | Description | Introduced |
|---|---|---|---|---|
| 10A1 | Tektronix | Plug-in | Differential amplifier plug-in | 1965 |
| 1S1 | Tektronix | Plug-in | 1 GHz sampling system | 1965 |
| 3A7 | Tektronix | Plug-in | Differential amplifier plug-in | 1965 |
| 3S3 | Tektronix | Plug-in | Dual-trace sampling plug-in | 1963 |
| 3T4 | Tektronix | Plug-in | Programmable sampling sweep plug-in | 1965 |
| 422 | Tektronix | Oscilloscope | 15 MHz portable dual-trace scope | 1965 |
| 502 | Tektronix | Oscilloscope | 1 MHz dual beam differential scope | 1958 |
| 5T3 | Tektronix | Plug-in | Timing plugin | 1965 |
| W | Tektronix | Plug-in | 8-23 MHz differential comparator | 1965 |