515

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15 MHz Tube scope Tektronix 515 front Produced from 1955 to (?) Manuals Tektronix 515 Manual (PDF) Tektronix 515A Factory Calibration Procedure, May 1960 (PDF) Tektronix 515A Factory Calibration Procedure, May 1960 (PDF, OCR) Tektronix 515A Factory Calibration Procedure, December 1968 (PDF, needs OCR) (All manuals in PDF format unless noted otherwise)

Manuals – Specifications – Links – Pictures

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 +2325 V for the CRT anode and -1675 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 available for 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.