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[[Image:Ths720std-comp.jpg|thumb|400px|right|Tektronix THS720 Std probe compensation]]
{{Oscilloscope Sidebar
|manufacturer=Tektronix
|series=THS series scopes
|model=THS720
|summary=100 MHz 2-ch portable digital scope
|image=Ths720std-comp.jpg
|caption=Tektronix THS720
|introduced=(?)
|discontinued=(?)
|designers=Murlan Kaufman;
|manuals=
'''THS710, 720'''
* [[Media:070-9245-00.pdf|Programmer Manual 070-9245-00]]
* [[Media:070-9246-03.pdf|Service Manual 070-9246-03]]
* [[Media:070-9247-02.pdf|User Manual 070-9247-02]]
* [[Media:070-9257-00.pdf|Reference Manual 070-9257-00]]


The Tektronix THS720 is a portable 100 MHz bandwidth 500 MS/s (each channel) two
'''THS710A, 720A, 720P, 730A'''
channel digital oscilloscope. There were two variants, the THS720 STD
* [[Media:061-4241-01.pdf|THS720A, 720P, 730A Release Notes 061-4241-01]]
and the THS720A.  The primary difference is that the THS720A will trigger
* [[Media:070-9731-05.pdf|User Manual 070-9731-05]]<br/><small>  Other versions: [[Media:070-9731-03.pdf|-03]] / [[Media:070-9752-01.pdf|-01]]</small>
from the DMM input.
* [[Media:070-9740-05.pdf|Japanese User Manual 070-9740-05]]
* [[Media:070-9741-01.pdf|Reference Manual 070-9741-01]]<br/><small>  Other versions: [[Media:070-9741-00.pdf|-00]]</small>
* [[Media:070-9751-01.pdf|Programmer Manual 070-9751-01]]
* [[Media:070-9752-02.pdf|Service Manual 070-9752-02]]<br/><small>  Other versions: [[Media:070-9752-01.pdf|-01]] / [[Media:070-9752-00.pdf|-00]]</small>
 
'''Other'''
* [[Media:061-4241-00.pdf|THS720A, THS720P, THS730A Release Notes 061-4241-00]]
* [[Media:061-4241-01.pdf|THS720A, THS720P, THS730A Release Notes 061-4241-01]]
* [[Media:070-9309-04.pdf|THS7CHG Instructions 070-9309-04]]
* [[Media:070-9750-02.pdf|THS720A MOD NV TekScope Component-Level Information Package 070-9750-02]]
* [[Media:THS7XXAPDiag.pdf|THS700 Schematics]]
* [[Media:070-9785-03.pdf|WaveStar Software User Manual 070-9785-03]]
* [[Media:071-1815-00.pdf|Memory Erasure and Memory Parts List 071-1815-00]]
 
* [[Media:3MW-10566-6.pdf|Tektronix THS700 Series Product Brochure (2006)]]
==Firmware==
* [[Media:THS720_v1.03_Firmware.zip|THS720STD v1.03 Firmware]] (ZIP)
* [[Media:THS710A_v1.11_Firmware.zip|THS710A v1.11 Firmware]] (ZIP)
* [[Media:THS720x_v1.16_Firmware.zip|THS720A, THS720P v1.16 Firmware]] (ZIP)
}}
The '''Tektronix THS720''' is a portable 100 MHz, 500 MS/s (each channel) dual-channel digital oscilloscope with isolated inputs.
 
There were two variants, the THS720 STD and the THS720A.  The primary difference is that the THS720A will trigger from the DMM input.
 
The '''THS720P''' includes features for electrical/power electronics measurements.
 
[[Murlan Kaufman]] designed the THS700 series high voltage isolated front end.
 
{{MissingSpecs}}
 
See [[THS720/Accessories]] for details on cables and other accessories.


==Operation==
==Operation==


Due to the isolated inputs, the probe ground must be connected even when
Due to the isolated inputs, the probe ground must be connected even when compensating the probes with the "PROBE COMP" output.   
compensating the probes with the "PROBE COMP" output.  It can be used with
It can be used with any BNC probe but the scale factor pin found on many Tektronix probes is not used.   
any BNC probe but the scale factor pin found on many Tektronix probes is
The vertical menu has a scale factor entry (1×, 10×, 100×, 1000×) which can also be used for direct BNC inputs.
not used.  The vertical menu has a scale factor entry (1X, 10X, 100X, 1000X)
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.   
with protected grounds for isolated measurements.  The [[P5102]] has the best
The [[P5102]] has the best isolation, allowing 600 V between reference ground and earth ground.
isolation, allowing 600V between reference ground and earth ground.
 
==Links==
* [https://www.eevblog.com/forum/testgear/tek-ths720a-portable-scope-teardowndiscussion// EEVBlog Forum thread on The THS7XXX series scopes]
* [https://www.youtube.com/watch?v=ajKtOf3kfuw Tektronix THS700 Series Oscilloscope Mega Video] by Near Far Media @ YouTube
{{Documents|Link=THS720}}
{{PatentLinks|THS720}}


==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 3¾-digit Maxim MAX134CQH.
 
The analog scope section starts with an attenuator hybrid driven by four channels of HP (now Broadcom/Avago) optoisolators and NEC relays. 
The hybrid contains the AC coupling capacitor and many laser trimmed resistors along with a custom Tek chip ([[165-2545-00]]) in a BGA package.
The signal then passes through a single-ended to differential transformer and goes to a custom-labeled Maxim two-channel high speed A/D converter ([[234-1503-20]]).
Note that the differential signal layout for channel 2 is not as good as channel 1 since one side of channel 2 goes through 2 vias not found on channel 1.
These optoisolators sometimes drift, causing a DC offset issue. They can be directly replaced with Broadcom/Avago part number HCNR201 (any of the -300E, -500E, -350E, or -550E variants will work) which are still readily available.
 
Firmware is updated using the [[067-1436-00|067-1436-00 Communication Pod]] with an adapter cable via an internal connector.


The analog scope section starts with an attenuator hybrid driven by 4 channels of
A THS710A and THS720A can be upgraded to a THS720P with the removal of a few resistors on the main board (see pictures for details). No adjustment/calibration is required after this modification.
HP (now Avago) optoisolators and NEC relays.  The hybrid contains the AC coupling
capacitor and many laser trimmed resistors along with a custom Tek [[165-2545-00]] BGA.
The signal then passes through a single-ended to differential transformer and
goes to a custom labeled Maxim 2 channel high speed A/D converter [[234-1503-20]].
Note that the differential signal layout for channel 2 is not as good as channel 1
since one side of channel 2 goes through 2 vias not found on channel 1.


==Repair Issues==
NOTE: A THS710STD can be upgraded to a THS720STD, but due to main board differences, these models CANNOT be upgraded to a -A or -P model<br>
Additionally, lower model scopes cannot be upgraded to a THS730A due to different input hybrid modules being used in the THS730A to provide the increased bandwidth.


The service manual shows how to remove the calibration protection jumper.
==Software==
The DMM calibration step requires a good calibrator capable of doing 850 VDC,
* [[Media:066-0109-00.zip|DOS program to display FFT - 066-0109-00]] (ZIP)
and 600 VAC at 500 Hz. Scope calibration is much simpler requiring only a
* [[Media:066-0153-00.zip|THS General Extended Logging Feature Software - 066-0153-00]] (ZIP, 48 KB)
square wave pulser and a DC voltage source. Note that after a cal fail, there
* [[Media:Wintek32.zip|Wintek32 THS General BMP Extractor v2.0.5.21]] <small> Other versions: [[Media:066-0154-00.zip|066-0154-00 v2.01]] (ZIP, 90 KB)</small>
is an error log in a nearby menu indexed by power on count.
* [[Media:Wavestar_2012.05.09.11.07.29_16456_EN.zip|Tektronix Wavestar 2012.05.09.11.07.29 16456 EN 066-0934-03]] (ZIP, 102MB) ''Product Key: WSTRO618650124''
* [[Media:Docuwave_1.2.zip|Docuwave 1.2 for DOS]] (ZIP, 704 KB)
* [[Media:THS7XX_v1.3.zip|THS7XX HardCopy by Marco M. Schäck]] (ZIP, 63KB) [https://www.schaeck-online.de/download/?dir=THS7XX%20HardCopy www.schaeck-online.de]


When confronted by scope calibration failures that say "Cal error, DC balance"
==Pictures==
and there are persistant DC offsets that increase with the attenuator settings
'''THS720'''
try replacing U45 and U46. They are HP CNR201A analog optoisolators, now made
<gallery>
by Avago as the HCNR201-300E. They send a low pass filtered version of the
ths720std-comp.jpg|THS720STD Displaying probe compensation waveform
input signal across the isolation barrier to give the DC levels that can not
THS720STD_PCB_Top.jpg|THS720STD Top of Main PCB
cross the high frequency transformer isolation barrier.
<!-- ths720std-mcudmm.JPG|THS720STD main board MCU and DMM -->
<!-- ths720std-powerbnc.JPG|THS720 STD main board BNC inputs and power supply -->
THS720STD_PCB_Bottom.jpg|THS720STD Back of Main PCB
ths720std-attenuator.JPG|THS720STD Attenuator with cover removed
<!-- ths720std-scopeanalog.JPG|THS720STD Analog scope section -->
ths720std-runningboard.jpg|THS720STD Operation without case
</gallery>


The battery pack is, of course, custom. It appears to be 4 C cell NiCd pack
'''THS720A'''
with the positive terminal moved to a ring around the bottom (most negative) cell.
<gallery>
If you are not concerned with interchanging packs or using the separate charger, the
Tek ths720a 1.jpg
cells can simply be soldered into the lower housing.
Tek ths720a 2.jpg
Tek ths720a 3.jpg
Tek ths720a 4.jpg
Tek ths720a 5.jpg
Tek ths720a 6.jpg
Tek ths720a 7.jpg
Tek ths720a 8.jpg
Tektronix_THS720A_to_720P_Hack.jpg|THS720P Upgrade mod
</gallery>


See [[THS700]] for the manuals.
'''THS720P'''
<gallery>
ths720p.jpg
THS720P_PCB_Top.jpg|THS720P Top of Main PCB
THS720P_PCB_Bottom.jpg|THS720P Back of Main PCB
</gallery>


==Pictures==
'''Accessories'''
<gallery>
<gallery>
File:Ths720std-comp.jpg|THS720 Std displaying probe compensation waveform
THS7CHG.jpg|Battery Charger
File:ths720std-toppcb.JPG|THS720 std top of main PCB
THS7CHG_Internal.jpg|Battery Charger Internal
File:ths720std-mcudmm.JPG|THS720 std main board MCU and DMM
File:ths720std-powerbnc.JPG|THS720 std main board BNC inputs and power supply
File:ths720std-backpcb.jpg|THS720 std back of main PCB
File:ths720std-attenuator.JPG|THS720 std attenuator with cover removed
File:ths720std-scopeanalog.JPG|THS720 std analog scope section
</gallery>
</gallery>
==Components==
{{Parts|THS720}}


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

Latest revision as of 04:46, 16 October 2024

Tektronix THS720
100 MHz 2-ch portable digital scope
Tektronix THS720

Produced from (?) to (?)

Manuals

THS710, 720

THS710A, 720A, 720P, 730A

Other

Firmware

(All manuals in PDF format unless noted otherwise)
Manuals – Specifications – Links – Pictures

The Tektronix THS720 is a portable 100 MHz, 500 MS/s (each channel) dual-channel digital oscilloscope with isolated inputs.

There were two variants, the THS720 STD and the THS720A. The primary difference is that the THS720A will trigger from the DMM input.

The THS720P includes features for electrical/power electronics measurements.

Murlan Kaufman designed the THS700 series high voltage isolated front end.

Key Specifications

  • please add

See THS720/Accessories for details on cables and other accessories.

Operation

Due to the isolated inputs, the probe ground must be connected even when 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 not used. The vertical menu has a scale factor entry (1×, 10×, 100×, 1000×) which can also be used for direct BNC inputs.

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

Links

Documents Referencing THS720

(no results)

Internals

Primary microprocessor is the Motorola/Freescale MC68331CFC16. An Intel E28F008SA120 Flash Memory chip is used for setup, cal and waveform storage. The switching power supply is run by a TL1451A, a TI two channel boost/buck controller. The DMM is a 3¾-digit Maxim MAX134CQH.

The analog scope section starts with an attenuator hybrid driven by four channels of HP (now Broadcom/Avago) optoisolators and NEC relays. The hybrid contains the AC coupling capacitor and many laser trimmed resistors along with a custom Tek chip (165-2545-00) in a BGA package. The signal then passes through a single-ended to differential transformer and goes to a custom-labeled Maxim two-channel high speed A/D converter (234-1503-20). Note that the differential signal layout for channel 2 is not as good as channel 1 since one side of channel 2 goes through 2 vias not found on channel 1. These optoisolators sometimes drift, causing a DC offset issue. They can be directly replaced with Broadcom/Avago part number HCNR201 (any of the -300E, -500E, -350E, or -550E variants will work) which are still readily available.

Firmware is updated using the 067-1436-00 Communication Pod with an adapter cable via an internal connector.

A THS710A and THS720A can be upgraded to a THS720P with the removal of a few resistors on the main board (see pictures for details). No adjustment/calibration is required after this modification.

NOTE: A THS710STD can be upgraded to a THS720STD, but due to main board differences, these models CANNOT be upgraded to a -A or -P model
Additionally, lower model scopes cannot be upgraded to a THS730A due to different input hybrid modules being used in the THS730A to provide the increased bandwidth.

Software

Pictures

THS720

  • THS720STD Displaying probe compensation waveform

    THS720STD Displaying probe compensation waveform

  • THS720STD Top of Main PCB

    THS720STD Top of Main PCB

  • THS720STD Back of Main PCB

    THS720STD Back of Main PCB

  • THS720STD Attenuator with cover removed

    THS720STD Attenuator with cover removed

  • THS720STD Operation without case

    THS720STD Operation without case

THS720A

  • THS720P Upgrade mod

    THS720P Upgrade mod

THS720P

  • THS720P Top of Main PCB

    THS720P Top of Main PCB

  • THS720P Back of Main PCB

    THS720P Back of Main PCB

Accessories

  • Battery Charger

    Battery Charger

  • Battery Charger Internal

    Battery Charger Internal

Components

Some Parts Used in the THS720

Part Part Number(s) Class Description Used in
Motorola 68000 156-1445-00 Monolithic integrated circuit 16-bit microprocessor 4041 • AM700 • DAS9200 • Keithley 182 • RTD710 • SG5030 • Prism 3002 • THS720
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