Is the price right? - Page 1
Forum section: electronics / testgear

author: Miti
author_rank: Super Contributor
timestamp: February 08, 2023, 01:47:17 am
content: A colleague wants to sell these three instruments. He wants $300 for the scope, $200 for the multimeter and $50 for the generator, all canadian dollars so the equivalent of about $410US. I found the following issues:HP34401 some cracks in the front panel glass and some of the segments are a bit dim. Functionally seems to be ok.TEK3012B - already hacked to 3052B the clock stops when the power is turned off, maybe the battery is dead.Wavetek the sine wave is a bit distorted at high frequencies.Would you pay this amount?Do I need them? No.Do I want them? Yees! Except for the generator.Cheers,Miti

author: Smokey
author_rank: Super Contributor
timestamp: February 08, 2023, 02:42:11 am
content: Scope only has like 14kpoints. That sucks now, but other than that it's ok (I used to use one of these). I'd say ya it's worth $300 if you don't already have a scope.Ebay Sold Listings Says: $300 to $700Meter: Another 6 1/2 digit meter? Yes Please.Ebay Sold Listings Says: $250 to $600Pass on function gen.

author: coromonadalix
author_rank: Super Contributor
timestamp: February 08, 2023, 02:54:41 am
content: the meter could have the unobtanium display ic, the serial number is a give away .... could be the vfd or the driver icthe tds3k series can be hacked ....

author: Miti
author_rank: Super Contributor
timestamp: February 08, 2023, 02:59:54 am
content: Thanks,I have three scopes, a Rigol DS1054Z, a Tek TDS210 and a Tek 2445B but no one goes to 500MHz…The VFD on the 34401 is worse than I thought. Please see below. Is there a cheap source for this VFD?

author: Miti
author_rank: Super Contributor
timestamp: February 08, 2023, 03:18:29 am
content: Quote from: coromonadalix on February 08, 2023, 02:54:41 amAs I said, I already hacked the scope. What’s with the display IC and the serial number?

author: Miti
author_rank: Super Contributor
timestamp: February 13, 2023, 04:27:26 pm
content: In the end I offered $150 CAD each and he accepted.The HP34401 FW is 07-05-02 and I see that the latest is 10-05-02. I couldn’t find any definite info if an upgrade would bring any benefit. Does it? Does it need calibration after if I decide to upgrade?Also the scope is at V3.39. Can it be upgraded without using floppy disks? Should I bother?Appreciate any pointing to some discussions about this.Cheers,Miti

author: Hydron
author_rank: Super Contributor
timestamp: February 13, 2023, 04:41:43 pm
content: Sounds like you got a great deal. Sure those scopes are horrible to use, but now you have the ability to go to 500MHz when needed.Probably no reason to upgrade the meter firmware, it's already new enough that you can enable some extra features too (search for "34401A hidden menu" thread), plus as a bonus the revision indicates that it has the newer display board that can be fixed if required. Not sure about sources for VFDs, am interested in one myself actually.

author: alm
author_rank: Super Contributor
timestamp: February 13, 2023, 05:28:33 pm
content: Quote from: Hydron on February 13, 2023, 04:41:43 pmWhy do you think the scopes are horrible to use? I used one as primary scope for years, and while it does not have the advanced analysis capabilities of a contemporary Lecroy scope, and memory depth is anemic compared to pretty much anything on the market these days, I never had complaints about usability. I always found the user interface very straightforward with much fewer layers of soft menus to wade through compared to modern scopes.

author: bdunham7
author_rank: Super Contributor
timestamp: February 13, 2023, 05:39:47 pm
content: Quote from: Miti on February 13, 2023, 04:27:26 pm$150CAD is very good in each case, that's more like the deals that you could find 3-4 years ago if you tried. The 34401A displays are available on eBay and your FW version is late enough that you won't have any issues nor do you need to worry about updating it.The scope may just need its internal cell replaced, I've no idea on updates. Does it have the communication module or battery? I see it has the FFT and Advanced Triggering keys, so if you've hacked it already I think you have a pretty maximal result for $150CAD. If you fix it and don't like it, I'm sure you can offload it for a profit.

author: Hydron
author_rank: Super Contributor
timestamp: February 13, 2023, 09:03:36 pm
content: Quote from: alm on February 13, 2023, 05:28:33 pmI recall being quite frustrated when using one, but it was quite a while ago and might have also included being limited by the memory depth as well as not liking the UI. Some of the more modern Tek scopes I've tried (you know the ones, early 2000s specs but high price, clueless people still buy them because of the brand name's history) really do have atrocious UIs (not the very latest lot mind, haven't tried them).

author: Miti
author_rank: Super Contributor
timestamp: February 14, 2023, 10:47:29 am
content: Thanks for your replies!This very nice colleague of mine says “BTW, I have another 34401a in the trunk if you want to check the display and swap it if it is better”. And it is much better, basically perfect. However, this second one was calibrated in 2001, the first one in 2012. That’s why I swapped the front panels. Now I’m thinking, should I buy the second one?About the scope RTC chip. Does it store anything important? Some say that it contains the MAC address some say only some hours of operation. Should I bother de soldering it and reading it or should I just dremmel it on the board?Cheers,Miti

author: robert.rozee
author_rank: Frequent Contributor
timestamp: February 15, 2023, 01:50:21 pm
content: sounds like you got a good buyfor photos etc of replacing the VFD on a 34401A, see here:https://www.eevblog.com/forum/repair/34401a-vfd-swap-some-useful-photos-and-notes/msg3349770i found the job of replacing the VFD relatively easy. but the photo you show (in Reply #3) of your VFD looks a little 'odd' to me, almost as if there is perhaps soot on the inside of the perspex filter rather than a failing VFD. could this be from some blown tantalum caps? in particular look at the "ERROR" annunciator, part is lit brightly while part is dim. can others please comment? my own experiences are with a sample size of exactly one.cheers,rob :-)

author: Smokey
author_rank: Super Contributor
timestamp: February 15, 2023, 07:19:04 pm
content: Did you get both 34401As? If you don't want one of them, I may be able to help you "rehome" it

author: thm_w
author_rank: Super Contributor
timestamp: February 16, 2023, 12:59:47 am
content: Buy both of the 34401A's and sell that 3478A.I wouldn't swap the displays over, unless the readings are massively off.

author: Miti
author_rank: Super Contributor
timestamp: February 16, 2023, 02:24:33 am
content: Quote from: Smokey on February 15, 2023, 07:19:04 pmI still have both but I haven’t decided what to do. I’ll test the second one this weekend and see how accurate it is.

author: Miti
author_rank: Super Contributor
timestamp: February 16, 2023, 02:34:55 am
content: Quote from: thm_w on February 16, 2023, 12:59:47 amNaah, I won’t sell my 3478A. It is dead accurate and with the extension module and backlight, it is my go to bench instrument. I will compare the three this weekend and decide if I keep them all. I also have a Fluke 8845A but the readings are a bit off on some ranges, compared to 3478A and compared to itself. What I mean is that it reads 3.00057V on the 10V range and 2.9986V on the 100V range for example. And there no way I can adjust the Fluke myself but I can adjust the others. So maybe I’ll sell the Fluke and calibrate the others with the money.

author: Miti
author_rank: Super Contributor
timestamp: February 16, 2023, 02:42:36 am
content: Quote from: robert.rozee on February 15, 2023, 01:50:21 pmI’ve opened them both and there’s no blown cap. It was removed from an ATS where it was left on for years. Looks like the anode is simply gone in that area. Error shows up when there is an error in the communication.