S-6

Manuals – Specifications – Links – Pictures

The Tektronix S-6 Sampling Head plug-in is a 50 Ω feed-through unit with a rise-time of 30 ps and bandwidth of 11.5 GHz. It was introduced in 1971.

The S-6 provides two unterminated 50 Ω SMA connections in a loop-through configuration as is convenient for TDR applications. It is good practice to leave a termination resistor on the unit when unused to give some protection against electrostatic discharge. The S-6 does not provide a trigger pickoff signal.

Key Specifications

Rise time	30 ps
Bandwidth	11.5 GHz
Operating input voltage range	1 Vp-p
Maximum single sample step	250 mV for less than 5% aberration
Maximum input voltage	±5 VDC
Input impedance	50 Ω (unterminated!)
Noise	< 5 mV of noise
Features	No internal trigger pick-off signal No internal termination

Internals

The S-6 is very similar to the S-4 in that it uses a 6-diode traveling wave trapped-charge sampling gate. This gate is implemented in the 155-0053-00 hybrid. Since the S-6 is a feed-through sampling head, the blow-by compensation is implemented slightly differently using a 10 k resistor in the hybrid directly connected to the input signal. The S-6 replaces the discrete preamplifier of the S-4 with two opamps from a 155-0035-00 quad opamp chip. The two other opamps are used to buffer the gate bias voltages.

Links

• S-6 internal photo and simulation
• Repairing an S-6 head (with internal photos)
• S-6 @ amplifier.cd 7S12 page
• S-6 @ barrytech.com

Prices

1979: $1,345 (~$5,300 in 2022 Dollars)

According to an internal memo, in 1979 annual sales were estimated at 225 units.

Pictures

• 

  S-6 front

• 

  S-6, entire plugin

• 

  S-6 sampling head and S-52 pulse generator head in a 7S12 TDR/Sampler plugin

• 

  S-6 with a black face plate

• 

  S-6 schematic

• 

  S-6 internal left side

• 

  S-6 internal right side

• 

  S-6 internal right side

• 

  S-6 internal left side, Preamp board removed

• 

  S-6 internal all boards removed, 155-0053-00 hybrid remains

• 

  S-6 Preamp board top

• 

  S-6 Preamp board backside

• 

  S-6 Strobe board backside

• 

  S-6 interconnect board

• 

  155-0053-00 hybrid sampling diode assembly

• 

  155-0053-00 hybrid sampling diode assembly (internal)

• 

  155-0053-00 hybrid sampling diode assembly with lid

• 

  155-0053-00 hybrid sampling diode assembly (internal)

• 

  155-0053-00 hybrid sampling diode assembly (internal)

Measurements

• 

  Impulse taken with S6 sampling head. Every dot is equivalent to one sample taken, and combined on the CRT with a rate of app. 100 Hz. Bright dots are newer than dimmed ones.

• 

  Incident pulse from an S-52 (nom. < 25 ps) displayed by an S-6 head (nom. < 30 ps), both installed in a 7S12. Displayed rise time ~35 ps confirms spec.

• 

  "Self Portrait" of an S-6: A pulse reflected on the unterminated "through" path (approx. 120 ps one way)

Components

Some Parts Used in the S-6

Part	Part Number(s)	Class	Description	Used in
152-0335-00	152-0335-00	Discrete component	step recovery diode	S-4 • S-6
152-0335-01	152-0335-01	Discrete component	150 ps step recovery diode	1502 • S-2 • S-4 • S-6
155-0035-00	155-0035-00 • 155-0116-00	Monolithic integrated circuit	quad op-amp	3110 • 3S7 • 3T7 • 492 • 492A • 492AP • 492P • 494 • 494P • 496 • 496P • 4010 • 4011 • 4012 • 4013 • 7L5 • 7L12 • 7L13 • 7L14 • 7L18 • 7S11 • 7T11 • 7S12 • S-6 • 1461 • 4602 • P7001 • 613 • 653
155-0053-00	155-0053-00	Hybrid integrated circuit	sampler	S-6