P6230: Difference between revisions

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|discontinued=(?)
|discontinued=(?)
|manuals=
|manuals=
* [[Media:070-4211-00.pdf|P6230 Operator's manual]] (PDF, OCR)
* [[Media:070-4211-00.pdf|P6230 Operator manual]] (OCR)
* [[Media:070-6027-00.pdf|P6231 Instructions manual]] (PDF, OCR)
* [[Media:070-6027-00.pdf|P6231 Instruction manual]] (OCR)
* [http://w140.com/tekp6203-p62204-p62205-p6217-p6231.pdf Tektronix P6203 P6204 P6205 P6217 P6231 Catalog Specs (PDF)]
}}
}}
[[File:P6230-1.jpg|thumb|right|250px|P6230 termination box]]
[[File:P6230-1.jpg|thumb|right|250px|P6230 termination box]]
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! Year
! Year
!   1984  
!   1984  
!   1985  
!   1987  
!   1987  
!   1989  
!   1989  
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! P6230 Catalog price
! P6230 Catalog price
|align=right|  $385
|align=right|  $385
|align=right|  $395
|align=right|  $395
|align=right|  $395
|align=right|  $420
|align=right|  $420
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|align=right|  –
|align=right|  –
|-
|-
! 2015 value
! In 2022 Dollars
|align=right|  $880
|align=right|  $1,100
|align=right|  $870
|align=right|  $1,030
|align=right|  $825
|align=right|  $1,000
|align=right|  $800
|align=right|  $1,140
|align=right|  $915
|align=right|  –
|align=right|  –
|-
|-
! P6231 Catalog price
! P6231 Catalog price
|align=right|  –
|align=right|  –
|align=right|  –
|align=right|  $410
|align=right|  $410
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|align=right|  $799
|align=right|  $799
|-
|-
! 2015 value
! In 2022 Dollars
|align=right|  –
|align=right|  –
|align=right|  –
|align=right|  $860
|align=right|  $1,070
|align=right|  $780
|align=right|  $980
|align=right|  $915
|align=right|  $1,140
|align=right|  $1,240
|align=right|  $1,550
|}
|}
   
   

Revision as of 02:59, 21 July 2022

Tektronix P6230
1.5 GHz, 450:50 Ω passive probe
Tektronix P6230

Compatible with 50 Ω scope inputs

Produced from 1984 to (?)

Manuals


Manuals – Specifications – Links – Pictures
P6230 termination box

The Tektronix P6230 and P6231 are passive ×10 (450:50 Ω) probes with 1.5 GHz bandwidth and DC offset capability, intended to minimize DC probe-loading effect when used on logic circuits.

The P6230 has an offset control potentiometer in the termination box and connects to the scope, e.g. 7000 series scopes, through a BNC connector with ×10 readout pin. It can be powered from 7000 series mainframes having LEMO S-series connectors for probe power, or compatible units such as the 1101.

The P6231 is a Tekprobe Level 2 probe intended for 11000 series plugins such as the 11A32 or 11A71. Offset control and power are provided by the scope mainframe through a Tekprobe BNC connector.

The P6230/6231 shares accessories with many other Tektronix subminiature modular probes although the input hybrid is unique. Tip color is yellow, connector end color is blue, part number 206-0279-00. Its end to end resistance is 400 Ω.

Key Specifications

Bandwidth DC to ≥ 1.5 GHz
Rise time ≤ 230 ps
Attenuation 10×
Input Impedance 450 Ω // 1.3 pF (1.6 pF guaranteed)
Signal delay 8.7 ± 0.1 ns
DC offset –5 V ≤ (Vsignal + Voffset) ≤ +5 V
Features
  • Readout Pin
  • Switchable 50 Ω termination

Internals

The P6230/6231 probes are sometimes described as FET probes or active probes, however, as the circuit diagram clearly shows, this is not correct. After the 400 Ω input hybrid, the AC component of the input signal is connected directly to the scope input through a 1 μF capacitor, then terminated in 50 Ω either in the scope input or the switchable terminator. The active circuit in the P623x, a standard NE5532 dual opamp, has the function of restoring and offsetting the input signal's low-frequency and DC components. This approach is similar to the feed-beside technique used in the 7104 scope and 7A29 amplifier.

Tek explains the raison d'être for the P6230/P6231 thus:

The P6230 acts as a standard 500 Ω passive voltage probe with the additional capability of having an adjustable tip "nulling voltage." This feature reduces the dc-loading effects on the probe when it is used to measure signals whose mid-voltage value is other than zero volts, or in circuits where the termination impedance is returned to other than ground level. The Input Bias/Offset Voltage may be adjusted so that at a particular test-signal voltage both ends of the probe input-resistor are at equal potentials and no current is flowing through the resistor.

ECL logic is most commonly operated from a -5.2 V supply with Vcc connected to ground. The output of an ECL gate is the emitter of an NPN emitter follower stage. The output is pulled down to a negative supply (about -2 V) with an external resistor (50 Ω to 100 Ω). Since speed is a major consideration in ECL designs, the interconnections between gates are often transmission lines, and the pull-down resistor doubles as a line termination.

If a standard 500 Ω, 10× probe without the input Bias/Offset feature were used to examine an ECL output, the probe's 500 Ω resistance to ground would form a voltage divider with the gate's output-termination resistor. This divider can cause distortion of the output signal levels, shift the DC operation point of the output transistor, and reduce the gate's noise margin.

The DC-load nulling capability of the P6230 helps to solve this problem. By adjusting the Input Bias/Offset Voltage to the ECL low level or to the termination voltage, the only effect of the probe resistance will be a small decrease in the ECL output-termination resistance. The effect of the probe on output voltage levels is negligible.

Links

  • P6230 / P6231 @ barrytech.com (incorrectly described as active probe)

Prices

Year   1984     1987     1989     1991     1995  
P6230 Catalog price $385 $395 $420 $525
In 2022 Dollars $1,100 $1,030 $1,000 $1,140
P6231 Catalog price $410 $410 $525 $799
In 2022 Dollars $1,070 $980 $1,140 $1,550

Pictures

Measurements