On Thursday 09 January 2014 08:57:47 Mark Wendt did opine: > On Wed, Jan 8, 2014 at 9:49 PM, Gene Heskett <ghesk...@wdtv.com> wrote: > > Pretty good take on it Gregg. > > > > I recall once, back in the late '80's, on an old character generator > > that had a sticky key problem, so I flushed it all out, several years > > worth of grit mixed with hand creams of dubious ancestry, with wd-40. > > 3 days later it had lost 3 keys. I called the CG folks who > > practically fainted when I said I had used wd-40 to clean it. > > > > They said put the phone down, and run, don't walk to the dishwasher, > > put it in the top rack and run at least 3 cycles with the last using > > just a squirt of palmolive. Turned out that the $16/copy Cherry > > brand key switches were hall effect devices that were being poisoned > > by the wd-40's petroleum content. In the end I wound up replacing 7 > > of them. It was a pretty heavy duty keyboard, similar to the old > > IBM's that weighed about 5 lbs and could be used to smash a skull in > > a pinch. It had by then probably typed a million words or more. And > > it probably did another million by the time we retired it 10+ years > > later. > > > > Cheers, Gene > > Tektronix had a rather nifty wash booth they used to clean up cruddy old > scopes and other test equipment brought in for repair and/or cal. > > http://www.radiomuseum.org/forum/tektronix_washing_your_instrument.html > > Mark
Interesting Mark. But I've never sent anything back to tek for repairs. When tek started to use the federal 5 year rule for parts availability to drive sales of new stuff was when I gave up on tek. When I walked in the door at WDTV in Oct '84, my predecessor had just bought a new 2235 scope. The tube was a POS with severe focusing problems and I immediately called the rep in Pittsburgh to get it replaced while it was still in warranty. No soap, it was good enough for them. I banged on them 2 or 3 times, because when I look at a scope trace and see a ghost sticking out of a spot 1/8" away, there really isn't a way to decide if its a duff tube, or noise in the circuit. This was in late 84 and things haven't improved. I put up with it for a few months, and finally convinced Mel I had to have a replacement tube or a replacement scope. He OK'd the tube, I bought it and put it in myself. Huge improvement. But in about 90, I began to note that the input attenuators on both sides were getting so out of whack in the frequency comp department that it was no longer capable of maintaining the 10x probes calibration when changing the range switch. So I got out the manual, and called tek to buy new ones as they are ceramic plates with the resistors and capacitors printed on the plate & baked on, totally non repairable. They didn't have any, it had been out of production for more than 5 years. Since I needed a scope that didn't lie to me, I went shopping and a year or so later bought a Hitachi V-1065 which served well, worked perfectly until I needed a 4 trace to be able to correctly setup the dvc-pro tape machines we had by then bought 15 of. So I traded the 1065 in on the top of the line 200mhz model, but that one had triggering problems so I backed down to the same thing in the 100mhz flavor, which did not have the triggering problem. That scope is still in daily use, although not like I used it, by my successor, and I would assume not seriously out of calibration yet and its now at least 20 yo. In the meantime, we had hired a pair of starving college & night school dropouts, and the guy had some stuff left over from a computer course he had taken which included a Hitachi V-1065 in mint condition, and which was then in their catalogs at $2750 new yet, wanted $1200 for it, I paid him $200 every payday for 3 months for it. Still have it. The range switches are getting noisy & need exercised to work right and the timebase is off a bit but the computer still gives the correct answers even if the trace misses the graticle marks by 10%. Their frequency rolloff at the high end, unlike the tek's brick wall, is generally just a loss of peak to peak ability, but I have used it to look directly at the output of a channel 8 transmitter, nominally 180 mhz to determine modulation depth, comparing it to a junk demodulator, coming to the conclusion that the demod truly was junk, something originally built for the cable industry. Very little is as believable as a Rhoade and Swarze AMF, but then that puppy was also $25,000 in its day, when I was making $9,000 year & thought it was good money. State of the art today, if we were still doing analog, would be an MSI-320 at about $5500. But you had better have a fresh calibration certificate, their business model demands it at least annually. Now of coarse we are doing digital, and the test & verification gear to monitor us accurately has quadrupled in price, but we are also 10x more needful of the accuracy than we ever were in the analog days. TBT, tek is no longer the standard setter. Hasn't been IMO for 25 years. Even our satellite trucks gear, which one would think would be a haven for tek, has none. Most of it is Israeli built stuff. And even being bounced around in a big ford van for about 50k miles a year, it generally Just Works(TM). If my V-1065 were to go up in smoke yet today, I likely would drop the card for whatever Hitachi is selling today that fits the 100mhz dual trace + computerized description. Why? Because from my experience, they Just Work(TM). For a very looooong time. Cheers, Gene -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) Genes Web page <http://geneslinuxbox.net:6309/gene> The best way to keep your friends is not to give them away. A pen in the hand of this president is far more dangerous than 200 million guns in the hands of law-abiding citizens. ------------------------------------------------------------------------------ CenturyLink Cloud: The Leader in Enterprise Cloud Services. Learn Why More Businesses Are Choosing CenturyLink Cloud For Critical Workloads, Development Environments & Everything In Between. Get a Quote or Start a Free Trial Today. http://pubads.g.doubleclick.net/gampad/clk?id=119420431&iu=/4140/ostg.clktrk _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
