Tektronix or BK - Page 1
Forum section: electronics / general

author: electronSpin
author_rank: Newbie
timestamp: November 30, 2011, 07:52:53 pm
content: I am currently thinking of getting a new power supply. Keeping y options open, I may either build one (as the current posts from Dave are showing how to do) or purchase one. The models I've been looking at are;Tektronix PWS4205 20V 5Ahttp://www.tek.com/products/dc-power-supply/pws4000/BK Precision 9121A 20V 5Ahttp://www.bkprecision.com/products/model/9121A/20v-5a-programmable-dc-power-supply.htmlBK Precision 9130 30V 3A * 2 + 5V 3Ahttp://www.bkprecision.com/products/model/9130/triple-output-programmable-dc-power-supply.htmlThey all have similar specs for load regulation, ripple and noise so forth. All the models even look similar on the outside The tektronix is a fair bit more than the BK 9121A (about $150).Is the extra money worth it for the tek, are they built better or is the extra cash just for the name? Does anyone have any experience with any of these models or have any suggestions/comments?Any help would be greatly appreciated.Peter

author: hacklordsniper
author_rank: Frequent Contributor
timestamp: December 01, 2011, 04:04:00 am
content: BK precision power supplies are just a rebadged various chinese units like itech.

author: electronSpin
author_rank: Newbie
timestamp: December 01, 2011, 04:34:58 am
content: O.K. Thanks good to know.

author: Unknown
author_rank: Unknown
timestamp: December 01, 2011, 05:26:47 pm
content: I wouldn't expect the Tektronix one to be an in-house design either (but I don't know this for a fact), maybe from one of the other companies in the Danaher group, just like the 'Tektronix' bench DMMs? Does Agilent have anything competitive in that price range? They design (most of) their power supplies.

author: electronSpin
author_rank: Newbie
timestamp: December 02, 2011, 02:35:09 am
content: Re-branding is really only a problem if the product becomes cheapened with inferior parts and bad workmanship. Re-branding is done in every market, sometimes for good and other times not so. The automotive and cellular industries seem to be good at repackaging things. In any case I'm still fairly cloudy on what I'm going to do. I have a tektronix hand held DMM and it has been great. No problems of any sorts, and I've had it for quite sometime now. Dave Jones did a tear down of an older BK power supply and I didn't like the inside at all; as some one mentioned, they didn't even use FR4.I looked at the Agilent but I never mentioned them before because I've never really like them (or HP). I've used the HP power supply but it just wasn't for me (completely personal, nothing to do with the equipment). Not everything can be for everyone!I wonder how each of them will do over the long term. Another point is that the Tektronix comes with a slim version of LabView.

author: robrenz
author_rank: Super Contributor
timestamp: December 02, 2011, 03:04:39 am
content: Keithley is having a 10% off sale on their power supplies.The best I can tell the teks are make by Keithley they look identical & identical specs(at a glance)http://www.keithley.com/products/dcac/highspeedpower/keisaleonlineThe prices shown are list price you can take 10% off those prices thru december.That makes them very competitve with the tektronix units.

author: hacklordsniper
author_rank: Frequent Contributor
timestamp: December 02, 2011, 05:53:10 am
content: Rebranding is a mistery. Sometimes they will add their secret sauce and the unit sold under a name of more serious comopany will actually be improved. Sometimes they will just change the name and increase the pric, and that is the most often case.

author: Bored@Work
author_rank: Super Contributor
timestamp: December 02, 2011, 05:59:32 am
content: Quote from: robrenz on December 02, 2011, 03:04:39 amThat would make sense, because Tek and Keithley belong to the same holding, and IIRC when Keithley was bought the holding announced that Tek would become responsible for them.However, I also do hate rebranding. It disguises the original source of an item, makes it much harder to judge the quality and harder to get spare parts/repairs.

author: hacklordsniper
author_rank: Frequent Contributor
timestamp: December 02, 2011, 07:52:11 am
content: Quote from: BoredAtWork on December 02, 2011, 05:59:32 amUsually original manufacturer will leave hints inside about who is the original manufacturer. Many rebadged things i have seen do actually have all the original manufacturers markings inside the device

author: Bored@Work
author_rank: Super Contributor
timestamp: December 02, 2011, 12:33:07 pm
content: Quote from: hacklordsniper on December 02, 2011, 07:52:11 amBut you can only inspect the inside after you bought the item.

author: BravoV
author_rank: Super Contributor
timestamp: December 02, 2011, 12:56:43 pm
content: Quote from: BoredAtWork on December 02, 2011, 12:33:07 pmAnd you can't inspect them, unless you intentionally want to void the warranty.

author: ejeffrey
author_rank: Super Contributor
timestamp: December 02, 2011, 01:15:57 pm
content: Also, it is a myth that when you pay a premium for a rebadged product you are paying for the support. This may occasionally be true, but it is not in general. Because the design, manufacture, and testing is done by a 3rd party, chances are there is nobody at BK / Extech / Tektronix / whoever that even knows how your product works. Some technical manager just picked a couple of items off a menu and sent a logo and color scheme choice to the OEM. Technical issues beyond "have you read the manual" and repairs will be sent on to the OEM. If you are lucky, they will at least have some units in stock to do an exchange for a defective product, but don't count on it.It isn't that these companies don't do a service: selecting reasonable models with good specs written in engligh, arranging international shipping and payment from china, and facilitating returns and exchanges. The problem is that these are the function of a distributor, not a manufacturer. I would much rather they just left the original badge on the product and sold that.

author: electronSpin
author_rank: Newbie
timestamp: December 02, 2011, 03:50:31 pm
content: I think your right with Keithley and Tektronix. Once you take 10% off Keithley, the product has the same price as its tek counterpart. Now the only issue is I couldn't buy a Keithley PS even if I wanted to! The distributors Keithlety mentions on their website seem to carry both Tek and Keithley products but only the power supplies under the Tek name brand. I can't buy from Keithley website as I don't live in the USA. In this case it looks like the Keithley line is priced higher than the Tek line for the same product (though I haven't looked on the inside so I really can be 100% sure).

author: Unknown
author_rank: Unknown
timestamp: December 02, 2011, 09:24:19 pm
content: I agree with ejeffrey, support for rebadged equipment is usually worse than for in-house design. Support and documentation for the Agilent-branded Rigol scopes was notably worse than the real Agilent scopes. Keithley is unable to fix any of the firmware issues in the Keithley 2100 because they did not develop this firmware. Tektronix had a range of low-end test equipment (eg. CFG250) in the early nineties, this was basically identical to mediocre equipment from some Asian OEM, except for a few knobs. Support consisted of just replacing failed units, since the Tek service center didn't have any service documentation. Quality was also below the Tek designs. This is why I'm skeptical about their current range of commodity test equipment.As far as I know, Tektronix' only low-end products are oscilloscopes, since they're traditionally a scope company (they essentially invented the 'modern' triggered sweep scope). Most of their other products (eg. logic analyzers, spectrum analyzers, function generators and all kind of specialty gear) is aimed at higher market segments. Same for Keithley, power supplies they design would be like SourceMeters and pA current sources.Quote from: electronSpin on December 02, 2011, 02:35:09 amFor a number of years Tek developed their own range of handheld DMM's. At least the high end models (TX3 and TX5) were original Tek designs, eventually sold to Fluke as the Fluke 183/185. The Fluke 180 and 280 series were derived from it. Not sure about the lower models.

author: electronSpin
author_rank: Newbie
timestamp: December 03, 2011, 02:36:46 am
content: It is too bad someone doesn't have a Keithley/tektronix power supply (2200 or 4000 series) they could crack open. Be nice to find out who is really making this stuff! It is getting pretty annoying to think you might be buying half-decent equipment only to find out they just put a sticker on what other wise would be garbage.It is too bad to hear that Agilent has done the no support game as wellThe specs on the Keithley/Tek certainly don't look bad, of course the question is for how long. It is an interesting observation that the data/selling sheets for the Keithley branded PS have a completely different focus than the selling sheets for the Tek branded PS. Looks like the brands are being used to penetrate two different parts of the same market, with one part willing to shell out more money than the other.Can anyone recommend any other companies? What has everyone else been using (or did everyone just build their own!) There doesn't seem to be any reviews for the Keithley or BK power supplies so I'm really back where I started (more or less)

author: hacklordsniper
author_rank: Frequent Contributor
timestamp: December 03, 2011, 05:43:58 am
content: Atten has nice power supplies.

author: electronSpin
author_rank: Newbie
timestamp: December 03, 2011, 03:53:07 pm
content: Thanks! I'll take a look at them.

author: Unknown
author_rank: Unknown
timestamp: December 03, 2011, 04:22:24 pm
content: Some experiences are posted on this forum. Not exactly unanimously positive.

author: hacklordsniper
author_rank: Frequent Contributor
timestamp: December 03, 2011, 09:03:50 pm
content: Quote from: alm on December 03, 2011, 04:22:24 pmFor the price they are great and they can be easy improved to your liking

author: termi
author_rank: Contributor
timestamp: December 09, 2011, 03:39:24 am
content: Since OP was interested in a BK 9130, I thought I'd post some pics of a partial teardown. I've had this unit for about a year, and it has worked great. The only downsides are the noisy fan (not temperature controlled) and the handle seems a bit flimsy for the weight of the unit. Otherwise it feels well built.

author: hacklordsniper
author_rank: Frequent Contributor
timestamp: December 09, 2011, 06:37:01 am
content: Looks quite nice, however i dont like they removed some part numbers

author: saturation
author_rank: Super Contributor
timestamp: December 09, 2011, 12:47:35 pm
content: You're paying a lot for the programmability in these linear supplies. On the spec sheet the 9130 is ~ 4205 spec wise.

author: hacklordsniper
author_rank: Frequent Contributor
timestamp: December 09, 2011, 01:25:46 pm
content: Quote from: saturation on December 09, 2011, 12:47:35 pmQuite more that its worth

author: saturation
author_rank: Super Contributor
timestamp: December 09, 2011, 03:25:14 pm
content: Yes, but one could justifying cost depending on the use. For convenience, its a luxury.If the owner can run through X+n tests/hr properly with these PSU versus X with an analog one, one could calculate income earned, and the PSU may pay for itself.Quote from: hacklordsniper on December 09, 2011, 01:25:46 pm

author: electronSpin
author_rank: Newbie
timestamp: December 21, 2011, 04:43:12 pm
content: Great work on the pictures; it was good to see the inside of the BK. Doesn't look half bad, though it is too bad you can't read all teh part numbers. Not sure what I'll do yet. Think I'll wait till after the holidays and see how much is left.

author: The_Penguin
author_rank: Regular Contributor
timestamp: December 21, 2011, 07:51:59 pm
content: Quote from: alm on December 02, 2011, 09:24:19 pmOops. I guess buying a "for parts or repair" CFG280 wasn't such a good idea after all.Guess I'll find out when it arrives. It was an obvious gamble anyway.