515
The Tektronix 515 is a 15 MHz single-trace all-tube oscilloscope introduced in 1955. It does not use plug-ins.
A rack-mount version, the RM15 was also sold. There is also a 515A (serial numbers 101 through 1000 are "Type 515", 1001 and upward are "Type 515A").
The 515A has a Z-axis input and slightly higher vertical sensitivity than the 515. Maximum vertical sensitivity is 100 mV/Div for the 515 and 50 mV/Div for the 515A. The 516 is essentially a dual-trace version of the 515.
The 515 and 515A are fan-cooled, both in benchtop and rackmount forms.
Key Specifications
| Channels | One vertical channel (two input connectors and a switch to select) |
|---|---|
| Bandwidth | DC to 15 MHz |
| Rise time | 23 ns |
| Deflection | 50 mV/div to 20 V/div (515A), 100 mV/div to 50 V/div (515) |
| Sweep | 0.2 μs/div to 2 s/div |
| CRT | T55 CRT CRT, P31 phosphor standard, 6 cm linear vertical deflection |
| Input impedance | 1 MΩ // 30 pF |
| Power consumption | 275 W |
| Weight | 40 pounds (18 kg) |
Links
- Tek 515A @ museum-nt.de
- Tektronix 515A checkout @ youtube.com
Internals
The HV power supply uses three 5642 rectifiers to produce +2,325 V for the CRT anode and −1,675 V for the CRT cathode. The LV power supply is linear, using a 6080 tube as the pass tube of the series regulator for +300 V and +100 V supply. The −150 V supply is regulated by a 6AU5 tube. The voltage reference for the −150 V supply is a 5651 tube.
The 515 and 515A use selenium rectifiers. A kit was later made availa blefor converting them to silicon rectifiers for improved reliability. Starting at serial number 4424, the 515A used the 120-142 power transformer, the same part that is used in the 516.
The vertical amplifier is fully differential, DC-coupled, and all tube. The stages are as follows:
- input buffer, cathode followers, 6AU6
- first gain stage, differential amplifier, T-coil, 12BY7
- unity gain buffer, cathode follower, 6DJ8
- output amplifier, differential amplifier, T-coil, 6CL6
The horizontal amplifier uses half of a 6DJ8 as a buffer, followed by a 6DJ8 as a differential amplifier and phase splitter, followed by the two halves of another 6DJ8 as the output cathode followers driving the horizontal CRT deflection plates.
The trigger is a 6DJ8 differential trigger amplifier followed by a 6DJ8 Schmitt trigger.
Pictures
RM15 front view
RM15 side view
Vertical signal path
RM15 top view
RM15 bottom view
515A
515A
515A
515A Left internal view
515A CRT circuit
515A HV power supply
515A HV power supply
515A HV power supply
515A
515A left internal
515A right internal
515A S1
515A S1
515A S1
515A S1
515A S1
RM15
RM15
RM15
RM15
RM15 rear
515A
515A
Blue 515A
Some Parts Used in the 515
| Page | Class | Description | Used in |
|---|---|---|---|
| 120-0080-00 | Discrete component | power transformer | 515 |
| 5642 | Vacuum Tube (Diode) | directly-heated high-voltage rectifier | 310 • 310A • 316 • 317 • 360 • 453 • 502 • 502A • 503 • 504 • 506 • 513 • 515 • 516 • 524 • 529 • RM529 • 533 • 533A • 535 • 536 • 543 • 543A • 543B • 545 • 545A • 545B • 547 • 551 • 555 • 556 • 567 • 575 • 581 • 581A • 585 • 585A • 647 |
| 6CL6 | Vacuum Tube (Pentode) | miniature power pentode | 132 • 310 • 310A • 316 • 317 • 515 • 524 • 525 • 531 • 535 • 535A • 545 • 545A • 545B • 549 • 581 • 581A • 585 • 585A • 3A74 |
| 6DJ8 | Vacuum Tube (Dual Triode) | dual triode | 80 • 132 • 161 • 310A • 316 • 317 • 3A75 • 502 • 502A • 503 • 504 • 515 • 516 • 519 • 526 • 529 • RM529 • 533 • 535 • 536 • 543 • 544 • 545 • 545A • 545B • 546 • 547 • 549 • 555 • 556 • 565 • 581 • 581A • 585 • 585A • 661 • 2A60 • 63 • 2A63 • 3A7 • 3A8 • 1121 • 1A4 • 67 • 81 • 82 • 86 • 3B1 • 3B4 • 1S1 • B • O • W • Z • Telequipment S32A • Telequipment D52 • Telequipment TD51 • Telequipment S52 • Telequipment S51 • Telequipment Type A |
| T0550 | CRT | CRT | 515 • 515A • 516 |
| T55 | CRT | CRT | 515 • 515A • 516 |