THS720: Difference between revisions

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[[Image:Ths720std-comp.jpg|thumb|400px|right|Tektronix THS720 Std probe compensation]]
[[Image:Ths720std-comp.jpg|thumb|400px|right|Tektronix THS720 Std probe compensation]]


The Tektronix THS720 is a portable 100 MHz bandwidth 500 MS/s (each channel) two
The '''Tektronix THS720''' is a portable 100 MHz, 500 MS/s (each channel) dual-channel digital oscilloscope with isolated inputs.
channel digital oscilloscope. There were two variants, the THS720 STD
There were two variants, the THS720 STD and the THS720A.   
and the THS720A.  The primary difference is that the THS720A will trigger
The primary difference is that the THS720A will trigger from the DMM input.
from the DMM input.


==Operation==
==Operation==
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compensating the probes with the "PROBE COMP" output.  It can be used with
compensating the probes with the "PROBE COMP" output.  It can be used with
any BNC probe but the scale factor pin found on many Tektronix probes is
any BNC probe but the scale factor pin found on many Tektronix probes is
not used.  The vertical menu has a scale factor entry (1X, 10X, 100X, 1000X)
not used.  The vertical menu has a scale factor entry (, 10×, 100×, 1000×)
which can also be used for direct BNC inputs.
which can also be used for direct BNC inputs.


Recommended probes are the [[P5102]] and the [[P6113B]], both are 10X probes
Recommended probes are the [[P5102]] and the [[P6113B]], both are 10× probes
with protected grounds for isolated measurements.  The [[P5102]] has the best
with protected grounds for isolated measurements.  The [[P5102]] has the best
isolation, allowing 600V between reference ground and earth ground.
isolation, allowing 600V between reference ground and earth ground.
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==Internals==
==Internals==


Primary microprocessor is the Motorola/Freescale MC68331CFC16.  There is also
Primary microprocessor is the Motorola/Freescale MC68331CFC16.   
an Intel flash E28F008SA120 for setup, cal and waveform storage.  The switching power
An Intel E28F008SA120 Flash Memory chip is used for setup, cal and waveform storage.   
supply is run by a TL1451A, a TI two channel boost/buck controller.  The DMM is
The switching power supply is run by a TL1451A, a TI two channel boost/buck controller.   
a 3.5 digit Maxim MAX134CQH.
The DMM is a 3½-digit Maxim MAX134CQH.


The analog scope section starts with an attenuator hybrid driven by 4 channels of
The analog scope section starts with an attenuator hybrid driven by 4 channels of
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The service manual shows how to remove the calibration protection jumper.
The service manual shows how to remove the calibration protection jumper.
The DMM calibration step requires a good calibrator capable of doing 850 VDC,
The DMM calibration step requires a good calibrator capable of doing 850 V<sub>DC</sub>
and 600 VAC at 500 Hz.  Scope calibration is much simpler requiring only a
and 600 V<sub>AC</sub> at 500 Hz.  Scope calibration is much simpler requiring only a
square wave pulser and a DC voltage source.  Note that after a cal fail, there
square wave pulser and a DC voltage source.  Note that after a cal fail, there
is an error log in a nearby menu indexed by power on count.
is an error log in a nearby menu indexed by power on count.
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==Pictures==
==Pictures==
<gallery>
<gallery>
File:Ths720std-comp.jpg|THS720 Std displaying probe compensation waveform
ths720std-comp.jpg|THS720 Std displaying probe compensation waveform
File:ths720std-toppcb.JPG|THS720 std top of main PCB
ths720std-toppcb.JPG|THS720 std top of main PCB
File:ths720std-mcudmm.JPG|THS720 std main board MCU and DMM
ths720std-mcudmm.JPG|THS720 std main board MCU and DMM
File:ths720std-powerbnc.JPG|THS720 std main board BNC inputs and power supply
ths720std-powerbnc.JPG|THS720 std main board BNC inputs and power supply
File:ths720std-backpcb.jpg|THS720 std back of main PCB
ths720std-backpcb.jpg|THS720 std back of main PCB
File:ths720std-attenuator.JPG|THS720 std attenuator with cover removed
ths720std-attenuator.JPG|THS720 std attenuator with cover removed
File:ths720std-scopeanalog.JPG|THS720 std analog scope section
ths720std-scopeanalog.JPG|THS720 std analog scope section
</gallery>
</gallery>


[[Category:THS series scopes]]
[[Category:THS series scopes]]

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