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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 | 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 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 ( | not used. The vertical menu has a scale factor entry (1×, 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 | 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. | Primary microprocessor is the Motorola/Freescale MC68331CFC16. | ||
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 | 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 | The DMM calibration step requires a good calibrator capable of doing 850 V<sub>DC</sub> | ||
and | 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> | ||
ths720std-comp.jpg|THS720 Std displaying probe compensation waveform | |||
ths720std-toppcb.JPG|THS720 std top of main PCB | |||
ths720std-mcudmm.JPG|THS720 std main board MCU and DMM | |||
ths720std-powerbnc.JPG|THS720 std main board BNC inputs and power supply | |||
ths720std-backpcb.jpg|THS720 std back of main PCB | |||
ths720std-attenuator.JPG|THS720 std attenuator with cover removed | |||
ths720std-scopeanalog.JPG|THS720 std analog scope section | |||
</gallery> | </gallery> | ||
[[Category:THS series scopes]] | [[Category:THS series scopes]] | ||