Products > Test Equipment
TEK 7404 4GHZ scope on ebay
CSmith:
--- Quote from: free_electron on August 11, 2013, 07:39:11 pm ---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 The motherboard is obsolete as well.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.
--- End quote ---
I 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.
CSmith:
--- Quote from: marshallh on August 12, 2013, 03:18:04 am ---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.
--- End quote ---
Tektronix 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-instrumentation
They 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.
CSmith:
--- Quote from: edavid on August 12, 2013, 04:13:19 am ---
--- Quote from: krenzo on August 12, 2013, 12:33:45 am ---
--- Quote from: edavid on August 11, 2013, 07:23:28 pm ---Umm, this scope is being sold by the Tektronix surplus dept.
--- End quote ---
What makes you think that? The seller's description just says "BNC Surplus Electronics." Nowhere does it say the seller is affiliated with Tektronix.
--- End quote ---
I don't think that, I know it.
--- End quote ---
I 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.
matthuszagh:
--- Quote from: edavid on August 11, 2013, 07:23:28 pm ---The last one they sold on eBay went for $3550, but that was a real TDS7404 rather than a CSA7404.
--- End quote ---
What 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?
edavid:
--- Quote from: matthuszagh on April 20, 2023, 07:31:36 pm ---
--- Quote from: edavid on August 11, 2013, 07:23:28 pm ---The last one they sold on eBay went for $3550, but that was a real TDS7404 rather than a CSA7404.
--- End quote ---
What 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?
--- End quote ---
At 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.
Navigation
[0] Message Index
[#] Next page
[*] Previous page
Go to full version