Background
Enoki has been used DSO almost 30 years. Enoki bought Tektronix TDS310 at first and TDS2002 has broken down. Some Chinese DSO are very cheap. Should Enoki repair TDS2002, or buy a new one?
Summary
Enoki has bought Owon SDS1102 on 2020-10-01. SDS1102 offset is very low. Enoki would not find that new DSO GND noise (including offset) and high fine LCD, if repairing the old one.
経緯目的
壊れた TDS2002 の修理もしくは代替品購入を検討する。
要約
SDS1102 の LCD 精細度と GND ノイズは，TDS2002 を修理していたら明らかにならなかった だろう。
Old DSO repair or buy new one SDS1102 2020-10-04
TDS2002 LCD trouble
Vertical line defect
TDS had worked normally till 2018 as shown Photo1. But some abnormal vertical lines began to appear in 2020 as shown Photo2.
When the defected lines are not a lot, Enoki could observe waves if scrolling the wave horizontally.
Scale and Time Div unit information
Enoki has usually used DSO as DMM. The scale and time division value are displayed in the left bottom. The information were hardly visible in July 2020 as shown in Photo4 and Photo5.
More than 2/3 area in the left became black as shown Photo6 in September 2020 at last.
Repair or Buy new type
Would the TDS2002 br repaired replacing the LCD?
Aliexpress sells it for ¥17,000, while Amazon.co.jp sells 100MHz DSO less than ¥30,000. TDS2002 bandwidth is 60MHz.
DSO bandwidth
Higher bandwidth DSO captures wave shape in detail. And also it may captures spike noise that occurs abrupt MCU shutdown.
Owon SDS1102 Choice
Among 3 Chinese brands
Amazon.co.jp sells Hantek, Owon and Hanmatek 100MHz DSO. 'Hanmatek' brand is like Hantek. I misunderstood it for Hantek.
Hantek or Owon
I preferred Hantek than Owon comparing both specifications at first.
Owon is more popular than Hantek in Amazon.co.jp reviews, otherwise in Amazon.com.
Enoki made an inquiry of Hantek in China, but could not get a reply.
Although Owon has resellers in Japan, Hantek has none. So Enoki selected Owon.
No heat exhaust hole on the top
Enoki set up it and powered on and found no heat exhaust holes on the top as shown Photo7.
TDS2002 has holes, because it dissipates power and naturally warmed air flows upward. TDS2002 has holes in the bottom for incoming cool air as shown Photo8.
SDS1102 can get incoming air flow, when opening foot stand.
Measurement
SDS1102 displays measurements on the bottom of LCD. TDS2002 displays on the right side near the side buttons. TDS2002 is easier at a glance.
SDS1102 current measurement scaling may be useful.
Probe
The SDS probe BNC connector side consists of 3 parts as shown in Photo9. Its fitting is loose.
All the cheaper probes adjust on the connecter end.
The signal varies when human fingers grabs the cylindrical part.
While Tektronix probes consists of 2 parts only, and adjusts on the probe end.
The SDS1102 probe wire length is shorter. The short length is welcome to handle small circuit board on desk.
LCD contrast
SDS1102 LCD contrast ratio and pixel density are better than TDS2002. SDS1102 can read small characters.
Offset + GND noise
Enoki looked up SDS1102 GND noise shortening tip and clip after adjusting the probe.
The scale and time Div are 50 mVDC and 50 ms.
The measurement rms lowers less than 2mV 0.3h later, while TDS2002 fluctuates up to approximate 18mV when just powered on.
Initial aging
SDS1102 has been working continuous well almost 2 days long.
Conclusion
Exhaust heat effect
The top of SDS1102 is cooler than TDS2002, Enoki feels. It may be true. But the top enclosure panel temperature is not air flow.
With measuring air temperature in the top of enclosure of SDS1102 and recording measurement, Enoki may evaluate temperature drift or effect.
TDS2002 GND noise
Is it true that SDS1102 GND noise is far smaller than TDS2002?
Enoki thinks that TDS2002 input circuit deteriorated with dust or the board itself deterioration.
| SDS1102 | TDS2002 | |
| Bandwidth | 100MHz | 60MHz |
| Power | 15W | 30W |
| Year | 2017? | 2002 |
© Enoki 2020 October 4