515

The Tektronix 515 is a 15MHz single-trace all-tube oscilloscope. It does not use plug-ins. A rackmount version, the RM15 was also sold. There is also a 515A. The HV power supply uses tree 5642 rectifiers to produce +2325V for the CRT anode and -1675V for the CRT cathode. The LV power supply is linear, using a 6080 tube as the pass tube of the series regulator for +300V and +100V supply. The -150V supply is regulated by a 6AU5 tube. The voltage reference for the -150V supply is a 5651 tube. The 515 and 515A use selenium rectifiers. A kit was later made available for converting them to silicon rectifiers for improved reliability.

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, 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.

• Tektronix 515 Manual (PDF)

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  RM15 front view

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  RM15 side view

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  RM15 top view

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  RM15 bottom view

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