Some general questions about the MDO3000 - Page 1
Forum section: electronics / testgear

author: hololens
author_rank: Newbie
timestamp: November 01, 2015, 02:21:20 am
content: Hello, i just received a new MDO3014 + SA + MDO3BNDL kit. I quickly checked if everything was fine with the instrument and delivery and stumbled about a few things:a) It came repackaged i.e. the accessories were all put in a big envelope + a seperate box with the MDO3BNDL Licence and the Instrument in its plastik bag and foam wings. Doe these kits not come in the Tektronix boxes you see in the youtube videos? I am especially worried because of the next point.b) The central knob of the wave inspector is relatively loose, one can easyly wiggle it and even worse its not well centered, maybe a transport damage because of the repackaging?c) If nothing is connected the displayed signal has small negative offset, i would expect - the distortions being random - having a zero centered signal.I have attached pictures to visualize a) to c):

author: Hydrawerk
author_rank: Super Contributor
timestamp: November 02, 2015, 02:04:14 am
content: Was the scope sold by an authorized distributor?When I bought my Agilent DSOX2002A back in 2013as newfrom Farnell, there was no protective cover on the LCD screen ans the scope was not packed in any plastic bag. But the scope was OK and it works fine till today.

author: joesixpack
author_rank: Contributor
timestamp: November 02, 2015, 04:54:25 am
content: I am picking up an MDO3014 + SA + MDO3BNDL at the local UPS station tomorrow night after work (I didn't want them to leave it on my doorstep). They shipped me three separate packages via UPS. For comparison, I could post pictures when I receive it.Edit: I just saw you aren't in the U.S. Don't know if the packaging is the same internationally.

author: forrestc
author_rank: Unknown
timestamp: November 02, 2015, 06:19:50 am
content: Quote from: hololens on November 01, 2015, 02:21:20 amMy 3024 is a month old, and came just like the un boxing videos. Box with tray in the top holding all of the accessories, and the scope neatly wrapped and supported in foam. The licenses came separately. Also no loose knob.I am traveling so I can't check for sure on the offset but that doesn't sound right. I am almost positive that a unconnected probe results in a bit of noise centered around ground.

author: Orange
author_rank: Frequent Contributor
timestamp: November 02, 2015, 09:29:24 am
content: That knob is certainly not OK. Its not a B-brand scope from China where you can expect these things to happen.The offset looks OK to me, the scale is set to 1mV, with this settings most scopes have some sort of offset. It might improve when it's warmed-upThe boxing is questionable, if this is 'official boxing' from Tek, than I think they have a serious problem.Where did you get this from, was it perhaps a demo system, or refurbished system ??

author: nctnico
author_rank: Super Contributor
timestamp: November 02, 2015, 11:22:30 am
content: You can wiggle the knobs on many rotary encoders. Nothing new here.

author: OldSchoolTechCorner
author_rank: Frequent Contributor
timestamp: November 02, 2015, 02:20:23 pm
content: Quote from: hololens on November 01, 2015, 02:21:20 amYou have to let the scope warm up for a few minutes, then do a self cal. That normal. The knob sure be smooth, but certainly not loose and looks damaged as knob is tilted.

author: hololens
author_rank: Newbie
timestamp: November 03, 2015, 06:15:45 am
content: The device is on its way back to the sender. It was ordered from an official Tektronix partner. I find it hard to accept a new product being not in its original packaging especially in this price category. It was also wrongly repackaged (upside down according to the arrows on the box).I am not familiar with this device and did not read the manual hence the the questions on this forum. The device comes with a calibration certificate, what is that good for if one has to do a self calibration on initial usage as was suggested?

author: OldSchoolTechCorner
author_rank: Frequent Contributor
timestamp: November 03, 2015, 07:26:03 am
content: Quote from: hololens on November 03, 2015, 06:15:45 amThe offset is normal, you have to let the scope warm up for a bit and at the 1mV you will have offset. Now if you have it a 1volts/div and have that issue, even after power it on for a while around 30 minutes, then calibration is way off, or something is wrong with it. ALL scopes is recommended to do a use the Self Calibration feature ensures your scope is measuring accurately. The routine should be performed after the scope has been turned on for about 20 to 30 minutes to ensure it has equalized to ambient temperature of the room it's in. The check should be performed if the ambient temperature changes by 5 °C (9 °F) or more. It for calibrate channel sensitivity, offsets, and trigger parameters. It has nothing to do with the factory calibration and one of the reason in critical projects they keep the scope power on 24/7.