SC504

Manuals – Specifications – Links – Pictures

The Tektronix SC504 is an 80 MHz dual-channel oscilloscope plug-in for the TM500 system.

Key Specifications

Bandwidth	80 MHz (derated to 70 MHz from 35 °C to 50 °C ambient), 10 Hz AC coupling cutoff
Rise time	4.4 ns (derated to 5.0 ns from 35 °C to 50 °C ambient)
Deflection	5 mV/Div to 10 V/Div, 1−2−5, and ×2.5 variable; max. input 250 V (DC coupled), 400 V (AC)
Sweep	50 ns/Div to 200 ms/Div, 1−2−5; variable ×2.5 (to at least 0.5 s/Div); ×10 magnifier
Trigger	0.4 div or 60 mV, DC to 30 MHz; 1.5 div or 150 mV, 30 MHz to 80 MHz; AC coupling >50 Hz; AC LF REJ >10 kHz; HF REJ <50 kHz
Input impedance	1 MΩ // 20 pF
Ext Trig Input	1 MΩ // 24 pF (750 kΩ // 28 pF when not selected), max. 250 V DC+peak AC)
CRT	8×10 divisions of 6.35 mm (0.25") each; 12 kV acceleration, P31 phosphor; tubes 154-0730-05, 154-0859-00, later models (~1984+) 154-0859-01 with circuit changes
Calibrator	0.6 Vp-p @ 1 kHz
Power	approx. 26 W operating, <1 W in standby
Features	1-or 2-channel (chop/alt), Add (1+2), Subtract (1-2), X-Y mode (2 MHz, <3° to 50 kHz), single sweep

Links

• Repair Log: Tektronix SC-504 Oscilloscope (K6JCA)
• SC504 @ barrytech.com

Rear interface

The SC504 has dedicated rear interface signal inputs switchable from the front panel AC/DC/GND/Int DC coupling selectors. These are terminated in 50 Ω (max. 5 V_RMS, 0.5 W).

Additionally, it provides a trigger input, Z-axis input (±5 V), delayed gate input (ECL), gate select input (ground for ext gate), intensify input (ECL), Ch1 trigger output (>50 mV/Div, 30 MHz), triggered gate output (ECL), holdoff output (ECL), ramp output (0−10 V), sweep reset input, ready light output, and +5 V.

Internals

A slide switch under the right side cover allows the variable sweep control to be used as a variable holdoff control instead.

The SC504 uses some custom Tek ICs, namely the 155-0124-00 preamplifier (U4345), 155-0109-01 trigger (U3238), and 155-0122-00 A-B logic (U3158). There are two passive input attenuator hybrids (HY1520, HY1420) and two 155-0161-00 attenuator/amplifier hybrids (HY1530, HY1430).

The power supply uses the pass transistors provided by the two mainframe slots that the SC504 covers. Those on the right slot provide ±20 V from the mainframe's ±33.5 V rails, those on the left slot make +5 V from the +11.5 V rail and −5 V from the rectified 17 V_AC supply. Power is drawn from the right mainframe slot, the pass transistors are the only connections on the left slot.

Pictures

• 

  front panel

• 

  in operation (2ch)

• 

  in operation

• 

  top

• 

  right

• 

  right interior

• 

  left

• 

  left interior

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  bottom

• 

  bottom interior

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  rear

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  in operation

• 

  SC504 with non-Tek plug-ins

• 

  SC504 with FG501

• 

  SC504 with AM503 in TM503

Custom ICs used in the SC504

Page	Model	Part nos	Description	Designers	Used in
155-0109-00	M120B	155-0109-00 • 155-0109-01	trigger	Gary Vance	5B25N • 5B31 • 5B40 • 5B42 • 5B44 • 5S14N • 7B50A • 7B53A • 7B80 • 7B85 • 7B87 • 7B81P • 7B90P • 7S14 • 7612D • SC502 • SC503 • SC504
155-0122-00	M132A	155-0122-00	sweep control	Larry Gagliani	455 • SC503 • SC504
155-0124-00	M138	155-0124-00	horizontal preamplifier	Bob Nordstrom	455 • SC503 • SC504 • 2221 • 2230 • 2232 • 2336 • 2337
155-0161-00	H616	155-0161-00	attenuator and amplifier		SC504