TEK 7404 4GHZ scope on ebay - Page 1
Forum section: electronics / testgear

author: leafi
author_rank: Regular Contributor
timestamp: August 11, 2013, 04:36:04 pm
content: First of all Im not the seller and have no relation or anything to them.It is a tektronix CSA7404 20GS/s 4GHZ BW. Normally the 7404 series is over 10K on ebay but this one is currently really cheap. Im not sure if I should bid on it as a back up for my TDS7404. What do you all think. If anyone decides to buy this be aware you will need the tek adapters for anything you want to plug in. ie BNC or SMA or even a normal oscilloscope probe.Has anyone ever cracked tektronix unlock codes? I would love to get the full memory depth out of mine. It really pisses me off when they charge the customer for the memory chips as part of the BOM cost then disable them and make you pay them 10K or more to enable them!http://www.ebay.com/itm/Tektronix-TDS7404-Digital-Phosphor-Oscilloscope-4-GHz-20-GS-s-4-CH-Touch-Screen-/161082814779?pt=BI_Oscilloscopes&hash=item258148b13b

author: nctnico
author_rank: Super Contributor
timestamp: August 11, 2013, 06:09:52 pm
content: I'm quite sure the price will get close to market value towards the end of the auction. Then again this scope is intended as a communication signal analyser. There can be differences between a 'normal' scope. Regarding the unlock code: use a debugger to see what installing an upgrade code does. I think its just complicated enough so that someone who just knows how to use wordpad or regedit cannot unlock the extra memory.

author: krenzo
author_rank: Regular Contributor
timestamp: August 11, 2013, 07:05:14 pm
content: Yeah, the price is going to shoot way up as the auction comes to a close. Item Location: Beaverton, OR also indicates the seller is going to make a ton of money off of the sale as they bought it from the Tektronix surplus store. A friend bought one of their 6 GHz scopes from the store there for about $300.

author: Unknown
author_rank: Unknown
timestamp: August 11, 2013, 07:18:21 pm
content: The scope i always wanted...https://www.valuetronics.com/Manuals/TEK_TDS7000_Series_JM.pdfhttps://www.valuetronics.com/Manuals/Oscilloscope_Tutorial.pdfRefurbished: $16.500USD.Manufacturer List Price (US): $ 49,990Calibrated with Data: +$500usd.similar is the: HP/Agilent 54854Ahttp://www.metrictest.com/catalog/pdfs/product_pdfs/hp_54855a.pdfor LeCroy WavePro, WaveMaster & Waverunner serieshttp://teledynelecroy.com/oscilloscope/http://www.ebay.com/itm/LECROY-WAVEMASTER-8600A-6GHz-QUAD-20GS-s-DIGITAL-STORAGE-OSCILLOSCOPE-/230979397388

author: edavid
author_rank: Super Contributor
timestamp: August 11, 2013, 07:23:28 pm
content: Quote from: krenzo on August 11, 2013, 07:05:14 pmUmm, this scope is being sold by the Tektronix surplus dept.The last one they sold on eBay went for $3550, but that was a real TDS7404 rather than a CSA7404.

author: free_electron
author_rank: Super Contributor
timestamp: August 11, 2013, 07:39:11 pm
content: OH. Those horror machines....They are sluggish as hell. the user interface is written in JAVA and runs on a VM on top of windows 2000 ( or XP in later versions ) . the graphics are horrible ( they never heard about anti-aliasing so all icons look like drawn by an 8 bit machine... even a commodore 64 could make nicer graphics ) if you select an area on the screen , the selection rectangle lags at least a second behind where your mousecursor or finger is ( touchscreen) ...They use a customized intel motherboard with a special bios to boot. The scope card has a powerPC processor running VxWorks and needs to access the harddisk prior to windows booting. so they use a bus mastering PCI controller.This means you can't install bios updates , you can't enter the setup screen through <DEL> or <F2>. you have no control over the motherboard. The motherboard is obsolete as well.The hard disk has a special layout with a partition holding the VxWorks system and a separate partition with windows. Trash the harddisk and you are screwed ...Stay away from these machines.

author: nctnico
author_rank: Super Contributor
timestamp: August 11, 2013, 10:43:42 pm
content: Quote from: krenzo on August 11, 2013, 07:05:14 pmThat is probably an ancient TDS820.

author: leafi
author_rank: Regular Contributor
timestamp: August 11, 2013, 10:57:09 pm
content: I will definitely agree with all of the negatives spoken. It is slow as hell but it is rather hard to get a 4GHZ BW scope for cheap.

author: dr.diesel
author_rank: Super Contributor
timestamp: August 11, 2013, 11:17:58 pm
content: It does look it would make a good boat anchor, not completely worthless.

author: krenzo
author_rank: Regular Contributor
timestamp: August 12, 2013, 12:33:45 am
content: Quote from: edavid on August 11, 2013, 07:23:28 pmWhat makes you think that? The seller's description just says "BNC Surplus Electronics." Nowhere does it say the seller is affiliated with Tektronix.Quote from: nctnico on August 11, 2013, 10:43:42 pmNope, it was a TDS6604B or TDS6804B. It was missing the exterior case. He got it in the $300-$400 range. I saw it myself with the price tag still attached, and it appeared to be in complete working order.

author: EEVblog
author_rank: Unknown
timestamp: August 12, 2013, 02:36:43 am
content: Quote from: leafi on August 11, 2013, 10:57:09 pmWell yeah, if cheap bandwidth is what you want, you sorta have to take what you can get in the usability department.

author: EEVblog
author_rank: Unknown
timestamp: August 12, 2013, 02:39:23 am
content: Quote from: krenzo on August 12, 2013, 12:33:45 amAs in the whole case? The guts were just exposed?Still very cheap at that price!

author: echen1024
author_rank: Super Contributor
timestamp: August 12, 2013, 02:40:22 am
content: I need to get to Beaverton...

author: olsenn
author_rank: Frequent Contributor
timestamp: August 12, 2013, 03:10:12 am
content: Out of curiosity, what is it that takes the extra space for 2GHz+ scopes? I mean what exotic chips do they use to do that sort of work, or is it just a matter of adding a greater quantity of ADC's etc?

author: marshallh
author_rank: Unknown
timestamp: August 12, 2013, 03:18:04 am
content: They will probably be using their own inhouse-designed ADCs. The unit's big because they slapped an entire PC in there for a base platform. At the volumes they sell them at there isn't really any reason to cost optimize that out.

author: krenzo
author_rank: Regular Contributor
timestamp: August 12, 2013, 03:25:56 am
content: Quote from: EEVblog on August 12, 2013, 02:39:23 amNah, there was an inner metal chassis to it that was still covering the guts. I think it was the external plastic paneling that was missing. It was ugly but worked well. He also picked up those active Tek probes that cost a fortune for a few hundred bucks.After seeing that, I imagine there are locals that go to the Tektronix surplus store, pick up great deals, and then make a profit selling them on ebay. I was told Tektronix employees get first pick of the store for a few hours before it opens to the public though.

author: edavid
author_rank: Super Contributor
timestamp: August 12, 2013, 04:13:19 am
content: Quote from: krenzo on August 12, 2013, 12:33:45 amI don't think that, I know it.

author: free_electron
author_rank: Super Contributor
timestamp: August 12, 2013, 06:37:45 am
content: by the way , these machines do NOt have bnc inputs. it is a special connector made for tektronix. you need the adapter blocks and they are not provided.. the adapter blocks convert the input to SMA 50 ohm ... 4 volts peak peak input only ...in other words , if you ain't got the probes for this beast it is useless...same guy also has a TDS8000 for sale. another one of those useless machines. the main chassis frequently goes for a few hundred dollars... i've seen em go as low as 300$ ...the problem is the sampler heads. those go for 10K$ ... and without sampler heads that chassis is useless.

author: leafi
author_rank: Regular Contributor
timestamp: August 12, 2013, 09:20:57 pm
content: Quote from: EEVblog on August 12, 2013, 02:36:43 amYes sir you do. That is part of the problem trying to do high speed design on a bargain basement budget. When my 200Mhz DS2072 wont be able to handle the BW needs I need to step up to the beast. It did help me see an EMI problem I was having due to rise / fall time radiating and jamming a GPS module. But man is it SLOW!I just really hate that companies cripple your hardware and make you pay extra to enable things like memory or bandwidth when the price of the parts is already included in the price paid for the instrument. I wish I could enable all 10M sample memory but Tek wanted over 10K for a fricken code! WTF!

author: CSmith
author_rank: Unknown
timestamp: December 03, 2013, 05:06:40 am
content: Quote from: edavid on August 11, 2013, 07:23:28 pmI'm the lucky one who won that particular unit. Turns out that coming from Tektronix it came with all licensable features turned on.

author: CSmith
author_rank: Unknown
timestamp: December 03, 2013, 05:33:58 am
content: Quote from: free_electron on August 11, 2013, 07:39:11 pmI have both the TDS7404 and the TDS8000. They both use STANDARD NLX motherbaords that have merely had the BIOS logo changed to Tektronix. Both originally had different OEM vendors of motherboards, and all of them respond to F2 to enter setup. The hard drives of the TDS7000/TDS8000 have a standard FAT32/NTFS partition layout for Windows with the VxWorks drivers being hosted in a subdirectory. One can use standard hard disk tools to manipulate the hard drive image. (I happened to use Acronis' tools.)Per the above warning, I would be cautious of losing the original hard drive image, and I would suggest making a backup immediately upon receipt. One good reason is that locating original Tektronix OS restoration discs is becoming increasingly difficult, especially Windows 2000 or XP. Windows 98 discs aren't too hard to find if you don't care about proper network or USB flash drive support. A second reason is that the firmware maintains a backup of the calibration data in a CalCons directory underneath the VxWorks subdir. Many of these scopes are of the age that the Dallas POWERCAP lithium battery backup on the bottom A/D board has discharged through its 10 year lifespan. If the scope detects that the calibration data in corrupt in the NVRAM (perhaps due to a discharged battery), it will attempt to recover it from the backup copies on the hard drive. All of these error messages are occurring at the VxWorks serial console, and so the operator may be unwittingly using the scope in calibration recovery mode all of the time. Lose that hard drive image or wipe over it with a fresh copy of software, and you may be missing the important calibration data. The scope will still work, but only for coarse display of waveform data.The scopes are a bit sluggish. One can readily upgrade the processor from the original 566MHz Celeron to a Pentium III 800/850MHz depending upon the motherboard vendor.TiN boldly took his up to a P3 1GHz, though that technically is beyond the amperage capacity of the onboard VRM by quite a bit. I suppose that it is only about another 10% or so beyond the VRM amperage design limit, and considering engineering design margins, it will probably fly. The processor bump definitely makes the scope more usable.

author: CSmith
author_rank: Unknown
timestamp: December 03, 2013, 05:43:41 am
content: Quote from: marshallh on August 12, 2013, 03:18:04 amTektronix designs their own custom A/D converters in a Silicon Germanium process from IBM.http://www.tek.com/document/news-release/tektronix-first-employ-ibm-silicon-germanium-sige-new-test-instrumentationThey typically have to interleave many A/D converters together to achieve the advertised maximum sample rate. Back when the TDS7404 came to market in 1999, they had to interleave eight of those bad boys to achieve 20GS/s. More modern scopes can achieve that speed with a single A/D, so a top-end model can now achieve 100GS/s or more through interleaving.BTW, these SiGe parts operating in the multi-GHz range dissipate allot of heat, so a good bit of the chassis space is dedicated to thermal management.

author: CSmith
author_rank: Unknown
timestamp: December 03, 2013, 05:48:48 am
content: Quote from: edavid on August 12, 2013, 04:13:19 amI concur. I dealt with a Tektronix employee email address, and both of my scopes were sent directly from Tektronix in brand new Tektronix shipping containers with a Tektronix packing slip. One also must fill out Tektronix export control paperwork due to the export controls on high-end scopes, even though it's on eBay.

author: matthuszagh
author_rank: Frequent Contributor
timestamp: April 20, 2023, 07:31:36 pm
content: Quote from: edavid on August 11, 2013, 07:23:28 pmWhat does this mean? From a quick look at the user manual, the feature set of the CSA7404 seems to be a superset of the TDS7404. Am I missing something?

author: edavid
author_rank: Super Contributor
timestamp: April 20, 2023, 08:52:30 pm
content: Quote from: matthuszagh on April 20, 2023, 07:31:36 pmAt the time, TDS7404s were selling for more than CSA7404s, for some reason (maybe just buyer ignorance). The CSA7404 discussed in this thread sold for $3051.

author: matthuszagh
author_rank: Frequent Contributor
timestamp: April 20, 2023, 08:53:44 pm
content: Quote from: edavid on April 20, 2023, 08:52:30 pmAh ok I see, then I think I misread the tone of that post. I'd thought you were saying the TDS7404s were intrinsically more valuable, but it sounds like I was mistaken. Thanks for clarifying.