Tektronix CDM250 DMM & Delivery Story - Page 1
Forum section: electronics / testgear

author: xrunner
author_rank: Super Contributor
timestamp: March 17, 2015, 09:56:00 pm
content: As posted in the test eqipment score thread, I received to day two Tektronix CDM250s from Ebay seller for only $10.75. They were listed as"For parts or not working"As far as I can tell they both work perfectly, just need a light cleaning up. I may have to give one away to a new hobbyist for free.But here's the weird thing. All this time since March 11 I've seen no tracking info so I was concerned that the seller had not shipped them. My postman rang my doorbell today and had the DMMs, and said I could pay $18 for the delivery charge or just have it returned. I told him I already paid for the delivery, but he said look at the tag - it was a UPS label! I said basicallyHow did it get through the postal system? He said somebody probably dropped it off by mistake at the post office in Florida and they just went ahead and sent it through their system, and it got to me. Well that's kinda cool but I need to get reimbursed the shipping charges I paid the Ebay seller. I took a pic of the postman holding the package as proof and sent the Ebay seller the info. They said they would have to "talk to their manager". I said for additional proof just check the tracking number - there is no tracking information!This meter is pretty basic. It uses the ES5107 low power CMOS 3 1/2 digit A/D converter with LED display drivers.http://www.cyrustek.com.tw/spec/ES5107.pdfIt also has three regulators - +/- 5V and another +5V rail. But it's a nice little bench meter for backup or additional capability. I mean two for $10.75? Not bad.

author: Noise Floor
author_rank: Regular Contributor
timestamp: March 18, 2015, 03:20:18 am
content: USPS delivering UPS is not unheard of, or the other way around. Sometimes they "sub-contract" out a delivery based on several variables, however they typically mark the packages as such. Your situation is strange/funny in its own way.

author: Vgkid
author_rank: Super Contributor
timestamp: March 18, 2015, 03:37:42 am
content: Nice to see it using HRC fuses.

author: SeanB
author_rank: Super Contributor
timestamp: March 18, 2015, 04:38:29 am
content: I know where you can send the extra one to........

author: xrunner
author_rank: Super Contributor
timestamp: March 18, 2015, 02:04:27 pm
content: Quote from: Noise Floor on March 18, 2015, 03:20:18 amThe Ebay seller refunded the charge the post office charged me - all is well.Quote from: SeanB on March 18, 2015, 04:38:29 amWait - are you implying send it to you? Are you a beginner? You seem to know more than most of the beginners here ...If I did want to offer it to a beginner, how would I do it on the forum? If I posted a thread for a giveaway, I'd get many replies. How would I choose who got it? How would I know they were a beginner?

author: SeanB
author_rank: Super Contributor
timestamp: March 18, 2015, 05:42:48 pm
content: I would not like it, even though it is nice.Simple way is to run a poll in General, with the choices being beginner, intermediate and advanced, and simply choose the winner from a random post out of the thread. That is simple, and you can limit the entries to the USA/Canada only ( cue the hisses and such) and require them to simply state eg. what experience they have and how long they have been doing this. That way you get the basic info of the entries, and simply take a sheet of paper after closing the thread ( you are the creator so can lock it without having an admin do it) and write the numbers down of all the answers, then simply choose a random number however you want from there. check the winners (or all the entries) posts to see how long they have been here, and what posts they have made.Suggestions are to have been on the forum for at least a year ( or whatever you choose) and to have a minimum number of posts ( probably a minimum from before you announced the giveaway) as eligibility criteria. Then you also have to have them declare they are in a state where this is legal ( some states in the USA forbid lotteries or other "games of chance") before they enter, and they are liable for any charges relating to tax and duties in their state. then you simply choose the winner, and ask them via PM for a postal address and send the parcel off then announce it on the thread, then at your choice lock it again.

author: xrunner
author_rank: Super Contributor
timestamp: March 18, 2015, 07:10:00 pm
content: Wonder if the proprietor of this fine establishment would care? Or, another idea is to provide the DMM on behalf of EEVBlog as my token of appreciation and let him run some kind of contest or whatnot? Might be fun. I can use a flat rate box for delivery to the US. Better limit it to residents of the U.S.

author: tautech
author_rank: Super Contributor
timestamp: March 18, 2015, 07:24:19 pm
content: I have a similar dilema witha a pair of little CRO's I scored:https://www.eevblog.com/forum/testgear/aaron-bs-310s-cro-mini-teardowm/msg631936/#msg631936I will be offering them to newbies close to me only, preferably school aged.

author: SeanB
author_rank: Super Contributor
timestamp: March 18, 2015, 07:28:06 pm
content: Ask Dave, he does not bite. I think he would allow it.

author: xrunner
author_rank: Super Contributor
timestamp: March 18, 2015, 07:33:25 pm
content: Quote from: tautech on March 18, 2015, 07:24:19 pmDainty little things aren't they?Yea maybe we can get some donation contests going on the forum - might be entertaining.Quote from: SeanB on March 18, 2015, 07:28:06 pmOK.

author: xrunner
author_rank: Super Contributor
timestamp: March 19, 2015, 02:38:20 pm
content: Dave told me it was OK to run a beginner giveaway. All I have to do is figure out what I want to say for the requirements. I don't think this is a "lottery" per se it's a contest to see who can convince me they are a beginner and need a bench DMM. Only one person can get it so I can't be responsible for hurt feelings.Here's what I have so far -This is a contest for a free reconditioned and calibrated (by me) Tektronix CDM250 benchtop DMM. Since I am shipping it free it's only for residents of the Unites States (sorry).You must have a minimum of 10 postsandhave been a member of the EEVblog forum for 2 weeksat the time of this posting. If you have been a member for 2 weeks and only have 1 or no posts feel free to make it to ten posts provided the posts are not simply "Thanks for the info" or something simplistic.You have to convince me that you are really a beginner andneeda free benchtop DMM (i.e. you are not the kinfolk of a millionaire who would not need help procuring equipment). How you do this is up to you. Pictures would probably help. If you already have a handheld DMM this will not automatically disqualify you as benchtop DMMs are a very useful and helpful addition, and as a beginner you may already be in need of a second DMM.You would be able to post a picture of your work area showing where the DMM will be used and also of the DMM in use when you get it. If this is a problem explain why.I reserve the right to choose the final winner. I might choose the final three and then use a random number generator to pic the final one, so I won't feel so bad for the losers.I will ship free to the Unites States.Any non-beginner members are free to comment and ask questions, as long as they are helpful to the final determination.

author: xrunner
author_rank: Super Contributor
timestamp: March 19, 2015, 05:39:35 pm
content: The contest is being sweetened by another member - offering 2nd and 3rd place prizes! More details coming ...

author: SeanB
author_rank: Super Contributor
timestamp: March 19, 2015, 06:59:43 pm
content: Good, I like this idea.

author: xrunner
author_rank: Super Contributor
timestamp: March 19, 2015, 07:24:12 pm
content: Oh yea and the fine print -Allsalesgive-aways final, no warranties expressed or implied, equipment provided as-is, all responsibility for use and operation of supplied equipment remains the responsibility of the user, calibration not guaranteed, EEVBlog forum cannot be held responsible for any injury or loss related to mis-use of supplied equipment, etc. ,etc. , etc.

author: xrunner
author_rank: Super Contributor
timestamp: March 21, 2015, 05:17:29 pm
content: Update -New Ebay purchase arrived today - another CDM250. It was listed as "For parts or not working". Also, it said that the fuse was good but would not power on ...When I got it the fuse was indeed good, but the holder was not seated properly, When I properly seated it with a screwdriver - presto, it works.So there are very good bargains out there on Ebay if you are willing to take a chance!

author: tautech
author_rank: Super Contributor
timestamp: March 21, 2015, 07:44:41 pm
content: You must really love these things, well spotted.

author: xrunner
author_rank: Super Contributor
timestamp: March 21, 2015, 09:11:02 pm
content: Quote from: tautech on March 21, 2015, 07:44:41 pmNot really, but the one I just got came up at the same time I got the other two. I figured it would serve as parts if nothing else. It appears to be an earlier version of the CDM250, as it's not got the same rubberized handle and the case is a little different. If anyone wants to take a chance on something like this, I prefer it when they state it doesn't power on at all, because it's most likely a power supply issue which is a lot easier to fix than some quirky issue with the Megabrain chip and associated stuff hanging off it.This one sat in the sun too long and the color of the top case is now brown and it should be aquamarine. There is a way to restore plastic but It seems like a lot of trouble last time I looked at the process. I might see if Krylon has a color that matches it and shoot it with paint. I also might give this one away on the forum.

author: xrunner
author_rank: Super Contributor
timestamp: March 21, 2015, 10:10:16 pm
content: Oops - look what I found. A burned resistor. It's right after the V/ohms input. It isn't open though - it reads 16.7 k ohms. The service manual has a good troubleshooting section and it says that if either the volts or ohms are not working then one of the things in both sections they say to check is R39 among other things.What's funny is the meter appears to work & read correctly on both volts and ohms. Ithinkwhat is going on is that the 16.7 k is now part of the dividers and has been compensated out by a calibration. What do you guys think?In any case, I'm going to make it right and replace it with the proper value - 100 ohms.

author: xrunner
author_rank: Super Contributor
timestamp: April 19, 2015, 01:21:42 pm
content: LOL - somebody sent Martin Lorton a CDM250 to check out -

author: SeanB
author_rank: Super Contributor
timestamp: April 19, 2015, 04:10:55 pm
content: That was me......... Finally a meter that I cannot lose on the bench.