On 12/14/2011 09:42 AM, gene heskett wrote: > On Wednesday, December 14, 2011 09:02:43 AM Mark Wendt did opine: > > >> A bit off tangent, but Jon's post in the Encoder thread brought >> something to mind. I recently became the proud papa of a Tektronix >> 7623A O'scope, purchased off the Bay of E. It's a mainframe storage >> scope, capable of handling three plugins - two vertical amps and a >> horizontal timebase. I got that machine, a few different plugins, a >> number of probes, and some other odds and ends for less than $500. It's >> an analog scope, but in it's time, it was one of the high-end scopes >> that Tek made, and it's still going strong even at close to 30 years of >> age. >> >> This one is identical to the one I have: >> >> <www.ebay.com/itm/Tektronix-7623-Oscilloscope-Modules-and-Manuals-/23055 >> 2776690> >> >> You can get better prices by waiting a bit. I got mine for $100 plus >> shipping. >> >> A venerable high quality machine that you can use to help troubleshoot >> problems like the ones that showed up in the Encoder thread. >> >> Mark >> > > Mark, be aware, very aware that tek has one HUGE Achilles heel. Its input > attenuators are all custom, in house made parts. And they age out of > calibration, both for DC measurements and for waveform fidelity on the > screen, with square waves no longer being shown as square waves, and no > amount of fiddling with the probe comp screws can fix it. This starts to > get noticeable at about the same time tek takes advantage of the statutes > re service parts and discontinues the parts 5 years after production > ceases, or decides if they still have one, that it is worth 20x what it was > worth a year before when it was still subject to the federal parts > availability statutes. Been there, done that, threw it in the ditch when > it was 7 years old in one case, 8 in another, because I could not believe > what it was telling me. > > My now 25 year old Hitachi V-1065 (computerized, dual trace 100 mhz, > triggered& delayed sweep, good to at least 200mhz with some rolloff& loss > of headroom in the vertical amps) is still within a couple percent for any > measurement its simple computer can make including frequencies by > reciprocal of time. And the tube is as bright and sharp as it was when new > as of last night when I measured the baud rate on a serial data line I > thought was off. And yes, a midi port was running at about 37,000 baud. > The keyboard obviously ignored the data. :( > > I have worn out at least 8 sets of 10x probes in its time. The 200mhz > models I can get from MPJones are as accurate at $40 a copy as anything > else I've ever bought, and mechanically sturdier than Tek's $200/copy > versions. > > Sadly, the Tektronix that earned our trust as the final word back in the > early 60's, and had lifetime warranties on any in-house built parts > including their CRT's& power transformers, has been sold to the stock > market 25+ years back, and is no longer worthy of our trust as a standard > test gear item unless its still in warranty AND they will fix it. Note the > caps, voice of experience. Whether they will honor the warranty is 100% up > to the rep that sold it and there effectively is no warranty on anything > you didn't buy new from him. If you buy it new from Rudy, but move to > Jeffs territory, Rudy won't service it since its out of his area now, and > Jeff won't service it because he didn't sell it. Obviously, its been 15 > years since I have considered the purchase of anything from Tektronix. > > Cheers, Gene > Gene,
That's why I bought a 30 year old scope... ;-) I ain't too worried about Tek not honoring the warranty. I'm my own warranty. All the things you said about your Hitachi hold true for my Tek scope. And I've been picking and choosing Tek OEM probes for about $25 or less apiece. And, I have all the service, cal and operators manuals for the scope, probes and plugin modules. There are still a bunch of places that I can get OEM parts for the Tek scopes too, so I'm not terribly worried about non-availability of parts. Guys on the Tek mailing lists always seem to have parts carcasses that have tested good components too. Mark ------------------------------------------------------------------------------ Cloud Computing - Latest Buzzword or a Glimpse of the Future? This paper surveys cloud computing today: What are the benefits? Why are businesses embracing it? What are its payoffs and pitfalls? http://www.accelacomm.com/jaw/sdnl/114/51425149/ _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
