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Re: More "crispy display" ranting......
Brian Goldsmith
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From: "Jeff W" I came across this 7904 earlier today on the 'bay: ViewItem&item=3801633404&category=45005 Hmm, looks like an OK deal if it worked, as implied. But then as I read thru the text, I came across this statement: "Powers up with a crisp disp., no modules to test the unit. Guaranteed to power up." Huh? sez me. Crisp Display? Anyone that knows anything about 7K mainframes knows that without plugins, you have NO display, let alone a "nice crisp display". So since he has no modules, how does he know it has a "crisp display"? Enquiring minds need to know! **** Ask the seller,if nothing else it will make him realise that he is ,"just a little dodgey". Brian Goldsmith. Yahoo! Groups Links |
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Re: Manual for Philips PM3200
Andreas Troschka
For manuals and schematics about Philips equipment ask to Toine PD0MHS:
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73s de Andreas IK2WQI sreaves22655 wrote: Hello, |
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R7103
Andreas Troschka
This one is a TEKTRONIX R7103 1GHz analog scope, the rackmount version
of the 7104. I do own both bought during the last year. I've seen really seldom one, and this seems to be in really nice condition (riatla says) and it is calibrated. I don't think somebody will pay more than 500US$ (reserve price!) for it but remember you have also to add the plugins. To be honest you should push in at least a 7A29(also opt.04) and a 7B10/15. But I'd add also 7A24/26 to have the 1MOhm input lower BW alternatives to the 50Ohm of the 1GHz VAmp plugin, and some double timebase of choice. Pay attention on the 3! slots instead of 4 of the 7104! Anyway #3800875191 is the reference. Remember to let you tell about the status of the hard to find Microchannel CRT! I already own one so I'm not personally interested on this scope. Andreas. |
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Re: 7S/7T Sampling System
Craig Sawyers
Hi Stan
One thing that I did not see in the explanation below is what the risetimePPL measured 20ps as the rise time of the initial event, which exceeds spec of course. But remember that the 500ps delay line they used is only around 4" of rigid air line, not the 50 feet of flexible from the 7M11. This severely lenthens the leading edge with a specified 175ps rise, in spite of all the neat tricks that Tek do with compensation components. Also not mentioned is that the S4, when introduced in 1969, wasWell, I don't think they were knocking older samplers. The S6 was introduced in 1971, and the review had high praise for the *overall* performance of that particular head, even though the rise time is slower at 28ps. Aslo the HP1430A,B and C were in the same review, and the HP1340A was introduced in 1966 with the B and C in 1972. These also give much better settling than the S4, even though the "A" version predates it by three years. They measured 29ps for the A version and 22ps for the C. That review was dated February 1989. However, in spite of what they say, it depends on what you are measuring; if you are looking at only the leading edge, then the S4 is fine. But if circuit behaviour is being looked at out to the ns time domain it might not be the best choice. Craig |
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Re: Tunnel Diode for 1S1
Stan & Patricia Griffiths
Hi Gang,
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I certainly know the part is good. It is the correct firing current which means that it will probably bias correctly in the circuit. The capacitance is quite a lot greater than the original part so it may not switch as fast but it will probably switch OK. Depending on exactly where the tunnel diode in question is in the 1S1 circuit will depend on how well the 1S1 will work with a 152-0125-00 in place of a 152-0214-00. I don't know because I have never tried this before but I would not hesitate to try it. Stan w7ni@... PS I sell these TD's in my Parts Shop also: ----- Original Message -----
From: "Darrin Conniff" <djconniff@...> To: "Greyhawk" <greyhawkeng@...> Cc: <TekScopes@...> Sent: Monday, March 01, 2004 8:06 PM Subject: Re: [TekScopes] Tunnel Diode for 1S1 Hello Greyhawk,know it is quality product. Good luck. plug-in I bought at ebay! While I was cleaning the plug-in I found a Tunnel Diodewith one of its "legs" broken off. I unsoldered it just to see that thesecond leg was also defective. Does anyone know where to find this tunneldiode? It is D304 in the 1S1, Manual says:is there a possible substitution?---- Yahoo! Groups LinksService.
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Re: 647 cal fixture on ebay
Craig Sawyers
And there are/were MANY more.What Tom says about baud rate is quite correct. I was using e-mail at home while we were starting up a business back in 1985. Used an acoustic modem - sort of a pair of sucker pads that fitted on the telephone handset - which chugged along at 300 baud on a good day, and storage was measured in bytes - not even kilobytes. The text-messagers nowadays think they invented acronym-speak - but they are really just responding to communicating in a medium with a strict limit on the number of characters transmitted, viewed on a tiny cell-phone handset, just the same problem as we had in the early to mid '80s. If anyone is interested, there is a very complete list here I think my favourite, just remembered in browsing that list, is BOHICA (bend over, here it comes again). Craig |
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Tektronix Wire
jdpetrzelka
Been repairing some 500 series plug-ins lately, between the circuit
boards they use mechanical connectors, ribbon cables and some type of coax with little brass eyelets at the ends as plugs, the coax looks about like RG174 but something tells me it isn't. In the parts book it calls out the eyelets but I don't see a refrence to the coax, does anyone know what it is? Or where I can find some, I need about 10 -12 inches for a SC503. Thanks in advance for any info, Jon P. |
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Re: Is it advisable to turn intensity down when scope is idle (but displaying a signal) to preserve CRT?
That seems to be a matter of taste. For some people, if it is not retina
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burning, it is not on. I had hell of a time with test department at the last company. They knew that intensity should not be set high and that I will yell when I see the setting and still it was always set high and when I enter test, they would reach for intensity knob, whether scope was on or off; kind of Pavlovian reflex. Regards Miroslav Pokorni ----- Original Message -----
From: "Craig Sawyers" <c.sawyers@...> To: <tekscopes@...> Sent: Wednesday, March 03, 2004 3:47 PM Subject: RE: [TekScopes] Is it advisable to turn intensity down when scope is idle (but displaying a signal) to preserve CRT? upShould the scope intensity be turned down to some degree or all the wayI usually turn down the intensity on the scope right down if I'm doing too far; you just need a clear trace, not a retina burning event. |
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Scope 2225 manual
beanrocco
Hi,
Does anyone have a PDF version of the operator and/or service manual and/or calibration procedure for a 2225,50Mhz scope? If so, can you give me the link for download or could you send it to me by e-mail in three separate one. Regards, P.S. I already try the usual LOGSA,etc.. Benoit |
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7S/7T Sampling System
Stan & Patricia Griffiths
One thing that I did not see in the explanation below is what the risetime
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of the S4 is when the delay line is added. Usually the added input C due to a delay line degrades the risetime significantly which is why there is an optional delay line provided by Tek to use for this purpose when using any of the S1, S2, S4 type of heads. Also not mentioned is that the S4, when introduced in 1969, was probably the fastest risetime available in ANY scope at 25 ps. It is easy to critique someone's "state of the art" engineering 35 years later, calling it crude. Of course it was crude by today's standards! I think a more significant measure of how good a design is, is the answer to the question, "How many years did it remain a viable product for the manufacturer?" Of course it is not quite THAT simple since some very good products are terminated artificially early just because the manufacturer decides to do it. In any case the S4 was in production from 1969 through 1989 (21 years) and the only other product mentioned in the note below was the SD24 (1989 to 2001, which is only 13 years). If the SD24 appears in a Tek Catalog past 2001, I could not find it. 21 years is a LONG time for ANY product to be continuously marketed in the world of test equipment. It CAN'T be as bad as it sounds or it would never have lasted 21 years! Stan w7ni@... ----- Original Message -----
From: "Craig Sawyers" <c.sawyers@...> To: "TekScopes Yahoo Group" <TekScopes@...> Sent: Tuesday, March 02, 2004 2:28 PM Subject: RE: [TekScopes] 7S/7T Sampling System IWhile on the sampling gear subject, could someone tell me more about S4. inhave been told that construction of S4 is quite terrible, so stayedthat noise. I gentleman who told me about that, said that he theyaway from it and opted for S6.Well, there are some reports on the Picosecond Pulse labs website that produced during the 80's and early 90's with tests on sampling systems.showed a gradual rise in 4ns to a max overshoot of 5.5% followed by anexponential decay back to the 100% level requiring an additional 25ns."triggering of the TD. The falsely triggered TD pulse would then enter the S4's diodethe waveform continues to rise up to the 105.5% level in about 4ns. It thenand some units used by the author in the past have been as bad as 10%."really good write up by PPL is the SD24. The benchmark for their tests was the |
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Re: Is it advisable to turn intensity down when scope is idle (but displaying a signal) to preserve CRT?
Denis Cobley
Hi Ransom
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It's all a matter of opinion. The 2235A has an aluminised backing on the phosphor to eliminate most phosphor burn risks. However, any type op phosphor will degrade over time (even those very expensive new plasma displays). You can just reposition the trace a little ever now and then. If you left it for 5 years 24 x 7 then you might have a problem but in my opinion it's not going to be a problem. If you want to even out the wear on the screen, fill the screen with a 100Mhz sine wave while the timebase is set to 1ms/div and turn up the intensity to near maximum for a few hours - that should help make the intensity more even. The real problems are with the old screen storage scopes - they don't have the aluminium backing so they can burn more easily. As for CRT's - you can buy another scope on ebay for less than $200 so you can always get parts. Regards Denis Cobley ----- Original Message -----
From: "ransom peek" <ransom.peek@...> To: <tekscopes@...> Sent: Thursday, March 04, 2004 10:24 AM Subject: [TekScopes] Is it advisable to turn intensity down when scope is idle (but displaying a signal) to preserve CRT? While writing code for a PIC microcontroller, I have the PIC circuit |
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Re: More "crispy display" ranting......
Richard W. Solomon
In DC it's called "word smithing", elsewhere it's not
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referred to so kindly. Some of these guys are good, others have minimal comprehension of the "Kings English". Caveat Emptor Dick, W1KSZ -----Original Message-----
From: Jeff W [mailto:vwthingy@...] Sent: Wednesday, March 03, 2004 6:19 PM To: TekScopes@... Subject: [TekScopes] More "crispy display" ranting...... I came across this 7904 earlier today on the 'bay: ViewItem&item=3801633404&category=45005 Hmm, looks like an OK deal if it worked, as implied. But then as I read thru the text, I came across this statement: "Powers up with a crisp disp., no modules to test the unit. Guaranteed to power up." Huh? sez me. Crisp Display? Anyone that knows anything about 7K mainframes knows that without plugins, you have NO display, let alone a "nice crisp display". So since he has no modules, how does he know it has a "crisp display"? Enquiring minds need to know! Jeff Yahoo! Groups Links |
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Re: Is it advisable to turn intensity down when scope is idle (but displaying a signal) to preserve CRT?
Craig Sawyers
Should the scope intensity be turned down to some degree or all the wayI usually turn down the intensity on the scope right down if I'm doing something else for a while. But then again, I usually run at a fairly low brightness anyway - there simply doesn't seem to be the need to crank it up too far; you just need a clear trace, not a retina burning event. Craig |
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Re: 7S/7T Sampling System
Craig Sawyers
I have read postings about using some fast SchotkyI did this with a defunct S3a 1GHz sampling probe. The brige was toast (well, some of the diodes were leaky in reverse bias). Stan helped out by looking up the spec of the original bridge diodes for me. I found that the basic spec, most critically reverse leakage and capacitance were matched rather well with Agilent microwave Schottkys, HSMS8202. These are diode pairs in a single SOT23 surface mount package. By flipping one of them over, and soldering the pair of pins one edge together you end up with a bridge. Costs about 3 bucks. Replacing the defunct bridge with this one worked perfectly - specification of the resulting probe is exactly as it ought, full 1GHz bandwidth and aberrations well within spec. I suspect that this approach would work well with all the earlier samplers up to around 4GHz, including the S1 and S2. The most obvious difference between GaAs, silicon junction and Schottky is the foward voltage drop. GaAs is well over a volt, Si is about 0.7V, and Schottky is about 0.3V. As I said I had no trouble, but potential problems might arise with the reverse bias voltage and the magnitude of the strobe signal. Usually these have a preset pot associated with them, and so can be adjusted somewhat. With the 1S1, the early GaAs bridge diodes were replaced later with Si ones so it is certainly possible to do this on the 1S1. The reason for GaAs was it was the only way to get speed in the early days of samplers. Then silicon processing caught up, and GaAs production went into a bit of a decline until LEDs came along, which are based on metallic alloys of III/V semiconductors like GaAs. And now, GaAs is used in the very fastest transistor technologies, the so called HEMT (high electron mobility transistor) - these beasts still have useful gain at 150GHz plus. Later (and much faster) sampling heads like the S4 and S6 used Schottky diodes from day one. In fact to get the speed these are impressively tiny to get the capacitance and lead inductance down - the junction is only 3um x 3um, and ridiculously easy to vapourise with static discharge, and event that would ruin your day. The thick film, charge trap heads simply don't lend themselves to being fixed on these fast samplers; if you zap them they are scrap. Other things that sampler fixers might like to bear in mind is that "back diodes" (tunnel diodes with a very low peak current of about 100uA)are what the microwave fraternity now confusingly calls tunnel diodes. They are essentially used as zero bias detectors, and I think that close equivalents to the BD4 could be found. Likewise the snap-off diodes that are used in the strobe circuits are still available from the microwave component suppliers, now called step-recovery diodes. Anyone wanting a browse through this sort of arcana could look at The only tricky thing is true tunnel diodes, for which there is no chance of a commercially available equivalent. Craig |
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Re: 647 cal fixture on ebay
Miroslav,
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Those types of abbreviations or acronyms came into use back in the early days of personal computer communications, when modems were 300 Baud (and then 1200 and even 2400 baud), mainly because of the low bandwidth, AFAIK (as far as I know). I remember it well: At 300 Baud, even under the best line conditions, you could still see each individual character being displayed on your screen (or on your terminal's thermal printer!). So, to keep the number of characters that had to be sent and received as low as possible during a two-way conversation via modems, or while using a dial-up BBS (bulletin board system), many of those types of abbreviations were adopted. Sometimes, people who did NOT use any abbreviations and refused to do so were actually the targets of criticism, and possibly intense criticism, because they were wasting bandwidth (and (possibly many) other peoples' time). Some of the most-common ones, AFAIK, are: AFAIK = as far as I know IMO = in my opinion IMHO = in my humble opionion (and variants of these) IIRC = if I recall correctly (or) if I remember correctly ROTFL = rolling on the floor laughing (and variants, as mentioned by someone else) LOL = (either) laughing out loud (or) lots of laughs And there are/were MANY more. Regards, Tom Gootee Date: Tue, 2 Mar 2004 12:41:52 -0800 |
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067-0587-02 7000 Signal Standardizer Manual Needed
I have an 067-0587-02 7000 Series Calibration Fixture. I have no manual for it, so I have no idea how to check its performance/calibrate it before I use it to calibrate my scopes. SN is B031613 and it is about 1984 vintage. Can anyone tell me what documentation is available for this? Is there a regular Blue service/instruction manual with schematics, cal procedures, etc. Does anyone have one that I can download, buy, rent, or photocopy? Good clean pdfs would be fine, too.
Ditto on the rigid extender 067-0589-00 (obviously no calibration procedures), but I would like the user's manual or data sheet or whatever came with it. Ditto on the very old vacuum tube 067-0502-00 Calibration Fixture (Amplitude Calibrator an Comparator) |
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Is it advisable to turn intensity down when scope is idle (but displaying a signal) to preserve CRT?
ransom peek
While writing code for a PIC microcontroller, I have the PIC circuit
connected to the scope to see the waveform (sine wave, not changing position for example). I will leave the circuit connected to the scope, showing the sine wave while I modify the software, anywhere from a few minutes to half an hour. Then I download the modified software to the circuit and see what, if any change occurs on the scope (Tek 2235A). Should the scope intensity be turned down to some degree or all the way during this programming time to avoid phosphor degradation, or perhaps should the scope be turned off during these intervals? I understand that replacement CRTs are not easy or impossible to come by, and want this puppy to last! Any thoughts? Ransom Peek Fort Collins CO |
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More "crispy display" ranting......
Jeff W
I came across this 7904 earlier today on the 'bay:
ViewItem&item=3801633404&category=45005 Hmm, looks like an OK deal if it worked, as implied. But then as I read thru the text, I came across this statement: "Powers up with a crisp disp., no modules to test the unit. Guaranteed to power up." Huh? sez me. Crisp Display? Anyone that knows anything about 7K mainframes knows that without plugins, you have NO display, let alone a "nice crisp display". So since he has no modules, how does he know it has a "crisp display"? Enquiring minds need to know! Jeff |
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Re: 7S/7T Sampling System
Dennis Tillman
It is apparent to me now that a 7S14 would not meet Dan's (Dan Tulloss,
Senior Metrologist, National Test Equipment, Inc.) needs. I have one of each of the Tek sampling plugins: 7S11/7S12/7S14/7T11/7T11A, and all but one the sampling heads: S1/S2/S3/S3A/S4/S5/S6/S50/S51/S52/S53/S54) and I've used them all. From personal experience the 7S14 is my favorite because it is so simple. But because it is less capable than the others it is often overlooked. The 7S14 was a sampling system designed for people familiar with dual trace, dual timebase real time scopes. I recommended it for someone that has never used sampling before because it is easy to use and it is self contained. It works well up to 1GHz. They are available on eBay from time to time at a reasonable price (under $100). There is one auctioned right now (item #3801463517, current price $11.00) at < By the way, the only sampling head I am missing in my collection is the S42 (55pS Optical Sampling Head). Does anyone know where I can buy one? Thanks, Dennis -----Original Message----- From: Stan & Patricia Griffiths [mailto:w7ni@...] Sent: Wednesday, March 03, 2004 12:42 PM To: Dennis Tillman Cc: TekScopes Subject: Re: [TekScopes] 7S/7T Sampling System After reading Dennis's message, it occured to to me to look up the 7S14 in a Tek catalog. This is just a 1 GHz, two channel, 50 ohm sampler. Tek made a lot of earlier versions of this technology that are a LOT cheaper on the market than the 7K stuff. So if the 7S14 is really up to this job, you might want to consider the following: 661/4S1/5T1A (there are other plugins you could use in this system: 4S2, 4S2A, 4S3, 5T1, 5T3) 561A/3S76/3T77 (and lots of other plugins and mainframes you could use here, too: 561, 564, 561B, 564B, 3S3, 3S1, 3S2 [sampling heads required}, 3T77A, 3T2) There is also a 5000 series sampler: 5S14 The important thing to keep in mind is that you generally need some mainframe, a sampling vertical, and a sampling timebase to work as a system. Virtually all of the 661 system plugins will work together and virtually all of the 561A mainframes and plugins will work together. It may be tricky getting a system up and running, however. Fixing those old sampling systems was sort of "black magic" even when all the parts (tunnel diodes and GaAs diodes) were available new from Tek. Now, I suspect, you would need several "donor" instruments to find enough good parts and then there is still the "black magic" . . . I have read postings about using some fast Schotky diodes in place of some of Tek's GaAs diodes but I have no personal experience with this . . . Regarding the "black magic", I can say this. In the late 60's, I was one of the founders of an independent service company that specialized in only Tektronix stuff in Southern California (it was called Mobilscope, Inc. and we were based in Van Nuys, CA, and traveled Southern California in several "calibration trailers" right to the customer's doorstep.) Anyway, fixing and calibrating Tektronix sampling was our strongest suit and we used to do them for most of the other cal labs in LA who had to farm them out when they got stuck. We did a ton of them for large companies all over So. Cal. (No, I am NOT interested in doing any for anyone else at this point in my life! I have a bunch of old Tek sampling instruments and I hope to get several systems running eventually, for my collection.) I would consult with people who own some of this old sampling stuff and are trying to make it run, however. Email me about it and I will see if I have any advice for you. Stan w7ni@... ----- Original Message ----- From: "Dennis Tillman" <Dennis@...> To: "TekScopes Yahoo Group" <TekScopes@...> Sent: Monday, March 01, 2004 4:16 PM Subject: RE: [TekScopes] 7S/7T Sampling System Hi Dan,is slower (500 Mhz I think). I think the -00 is slower still. I ask becauethat will determine how fast the sampling heads need to be.with the 7T11. You will need a sampling head to go in the 7S11 such as anquite nice. They can be had cheaply. It occupies two slots. So on a 4 slotthat is in good condition. Need a good one to do some 067-0587-XX's. Notbeing re-sold...for my use...saw that being asked this morning. Yahoo! Groups Links |
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Re: 647 cal fixture on ebay
Stan & Patricia Griffiths
I've been a "ham" for 51 years and "IIRC" is a new one one me!
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My guess: "IIRC" = "In the Instance that you Really Care . . ." Stan w7ni@... ----- Original Message -----
From: "Miroslav Pokorni" <mpokorni2000@...> To: <tekscopes@...>; "Tim Phillips" <t.phillips@...> Sent: Tuesday, March 02, 2004 12:41 PM Subject: Re: [TekScopes] 647 cal fixture on ebay What does 'IIRC' mean? I presume, that is one of those cute ham operators |
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