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Teknet manuals
Hi guys:
If you read the info on the site there is a disclaimer that says that there may be omissions and that they are asking for information from the users to point out these problems. I believe they say that they will make sure you get a corrected copy. For a free service I don't know how much further they should go. They do have original copies for sale. Another point is that I have been to their facility and found that they are a very well qualified team of technical people. I was impressed with the people, the technical lab and the management. They are in the process of moving from the Chicago area to Atlanta. From my experience in technical management, I know that you don't relocate marginal people. They have a good inventory of equipment for sale. I may have missed the point but I was not aware that the primary business was rental. George Atlanta Sign up for Internet Service under $10 dollars a month, at |
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Re: lethality of HV
Craig Sawyers
A friend of mine is afraid to work on a three gun projector,It all depends on the current. For an anode accerating system, there is very little (or no) current, so the power supply only has small capacitors in the voltage multiplier. There is maybe 10-20 milliJoules stored. Remember that the human body has a capacitance of 160pF typically, and you get a static charge walking across a rug or stroking a cat of about 10kV in dry conditions. You can certainly *feel* that - it causes me to yelp every time I get out my car in dry weather - closing the door is a real adventure. As to the lethality, I don't know the formal details, but I gave myself a fright with my 7704A once. In a moment of brain fade I unplugged the HT from the CRT (with the scope off), and made the mistake of touching the exposed pin on the connector where it exits from the supply. Youch! Of course the capacitors hold the charge (duur), so you get a nice 21kV belt. It is enough to make you not want to repeat the exercise, but I'm still here to tell the tale. The anode supply in older scopes is far more dangerous, because you have maybe 500V after the rectifiers across around 150uF of smoothing capacitor. That is 9 Joules, and more than enough to send you off to the pearly gates if you grab it with a vengeance. Once the skin is punched through, the body's resistance is only around 100 ohms - so you get 5A flowing from the 500V for 15ms (RC time constant). A rather scary site at t.html says that 5A (but for 1 second) causes "Ventricular fibrillation (the rhythmic pumping action of the heart ceases.) Muscular contraction and nerve damage occur. Death is most likely." I guess that the energy comes into this - so 5A for 15ms is the same as 75mA for 1 second. They say about 75ms "Extreme pain, respiratory arrest, severe muscular contractions. Individual cannot let go. Death is possible." So watch that old tubed gear! Craig |
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Re: 7704a
Craig Sawyers
Would someone post a quick opinion on a 7704A with (3) 7A26 DualNice system. My every day 'scope is a 7704A with a selection of plug-ins depending on what I'm doing. I use the 7B80/85 combo though, becuase it allows you to do delta time measurements, whereas the 7B70/71 doesn't. Craig |
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lethality of HV
Robert Morein
A friend of mine is afraid to work on a three gun projector, which coincidentally has the same anode voltage as the 7704, 7904, etc, 24 KV.
It is my understanding that this voltage is not lethal, primarily because the CRT is too small to store a lethal charge. Elsewhere, I have read that the lethal threshold, at least as far as TV tubes are concerned, is around 32 inches. Comments? Any reassuring words for my friend? |
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Re: 7704a
Robert Morein
Great scope.
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The timbases are older than the scope, but compatible. The optimal timbaes are 7B80 (horizontal slot 2, main) 7B85 (horizontal slot 1, delaying) The 7A18 are inferior to the 7A26, but you can use them for high voltage experiments ;) The 7B53A does not reach the maximum sweep speed of the scope. It is compatible, but intended for the 7603 series. The 7D15 is a gem, and fits in horizontal slot 1. ----- Original Message -----
From: Brian Goldsmith To: tekScopes@... ; Dennis L. Wade Sent: Saturday, March 06, 2004 12:39 AM Subject: Re: [TekScopes] 7704a ----- Original Message ----- From: "Dennis L. Wade Would someone post a quick opinion on a 7704A with (3) 7A26 Dual Trace Amp, (2) 7A18 Dual Trace Amp, and one each of 7B70 Time Base, 7B71 Delay Time Base, 7D15 255 MHz Universal Counter Timer and 7B53A Dual Time Base. *** Nice!!!!! Quick enough? :-) Brian Goldsmith. ------------------------------------------------------------------------------ Yahoo! Groups Links a.. To visit your group on the web, go to: b.. To unsubscribe from this group, send an email to: TekScopes-unsubscribe@... c.. Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service. |
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Re: 7704a
Brian Goldsmith
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----- Original Message -----
From: "Dennis L. Wade Would someone post a quick opinion on a 7704A with (3) 7A26 Dual Trace Amp, (2) 7A18 Dual Trace Amp, and one each of 7B70 Time Base, 7B71 Delay Time Base, 7D15 255 MHz Universal Counter Timer and 7B53A Dual Time Base. *** Nice!!!!! Quick enough? :-) Brian Goldsmith. |
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7704a
Dennis L. Wade
Would someone post a quick opinion on a 7704A with (3) 7A26 Dual
Trace Amp, (2) 7A18 Dual Trace Amp, and one each of 7B70 Time Base, 7B71 Delay Time Base, 7D15 255 MHz Universal Counter Timer and 7B53A Dual Time Base. Thank you...Dennisopinion----------------- "If you can remain calm, you just don't have all the facts" Dennis Wade KG6ZI Carmichael, CA |
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Re: Bias batteries in 7S14
I was eager to check out the teknetelectronics site Jeans wrote about:My understanding is that 'membership' is free. They never collected any fees from me, did not even try to. Keep in mind that company is in rental business and purpose of this site is to substitute missing operating manuals. No rental customer repairs or calibrates equipment and I was surprised to find any service manuals. I guess, those are the ones that leaked through the system. The manuals I downloaded were incomplete and disorganized as if whoeverI would say, there is no 'as if', guy who ran paper through the scanner did not care what came out as long as it was any kind of image. Since I am into guessing business, I would say that scanning was done by a service company and when customer asked why pages are not aligned they told him that can be done, too, but price is triple. As for incomplete manuals, I would guess that parts were omitted to save the cost. As I already said, those manuals are intended for rental customers to use as operating instructions. Few manuals that have schematics, surprisingly one for 7S14 does, are possibly early scans, before accountants got billing for scans or ones that leaked through the system. I would be very hard pressed to argue differently, even when talking about good scans, like ones available on e bay, but for something that I would just glance at, like things that I do not own but am curious about circuit, scans would have to do. Any kind of a small paper manual (e.g. for plug-in) is upward from $10, frequently $20 and that makes it an expensive proposition. As for good way to scan fold out sheets, there is a claim by one e bay vendor that he has a scan of the whole page and if printed at the place that can handle B size paper, fold out sheets are usable. Have not seen any of those schematics, just saw vendor's claim. Regards Miroslav Pokorni |
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Re: Bias batteries in 7S14
Dennis Tillman
Hi Everybody,
I was eager to check out the teknetelectronics site Jeans wrote about: in hopes I could find a few of the really rare manuals I still haven't been able to locate for my collection. But the site is a bit of a disappointment. The quantity is there but the quality is lacking. When you sign up for the free 30 day trial you can download 5 manuals. But unfortunately you get what you pay for. They are free. But if the three Tek manuals I chose to download are any indication of the overall quality of the site I would not be willing to pay for a subscription. The manuals I downloaded were incomplete and disorganized as if whoever scanned them was not paying attention to what they were doing. Personally I prefer paper. Its much easier to grasp the big picture with a paper manual and as far as I know no one has yet to come up with a good way to scan the foldout pages. For those people who prefer their manuals in PDF format I would suggest buying from one of the people selling them like that on eBay. The eBay sellers have more of an interest in maintaining their reputation for doing a quality scanning job. Dennis |
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Re: 647 cal fixture on ebay
Snort!
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Seriously, it's not ham shorthand at all, it's chatroom shorthand, stands for If I Recall Correctly. Other related ones: AFAIK As Far As I Know YMMV Your Mileage May Vary These serve to delineate precisely how much you do *not* know about what you're talking about :) Regards, Dave Wise -----Original Message----- |
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Re: ligthing gel
Thank you, Craig. That was very smart of me: said 'lighting gel' and then
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went on about photographic filters. Regards Miroslav Pokorni ----- Original Message -----
From: "Craig Sawyers" <c.sawyers@...> To: "TekScopes" <TekScopes@...> Sent: Friday, March 05, 2004 1:09 AM Subject: [TekScopes] ligthing gel film,You did mention that lighting gel before, but I still do not besomething to be used to make custom photographic filters. The film must collapsing?very thin, to avoid optical distortions due wavy surface caused inPlease, explain the construction.Lighting gel is the stuff that is used in front of stage lighting in front of Tek scopes for sure - but it would certainly be better than |
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Re: Bias batteries in 7S14
Michael Dunn
At 12:22 AM +1100 2004/3/6, jeans wrote:
You can download the instruction Manual from TekNet at Thanks! I've added their URL to our Links page. I'd advise any members who haven't checked out that page to do so sometime. Lots of good stuff... Michael |
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Re: 7S/7T Sampling System
Ashton Brown
Craig, thanks!
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+11 Informative.. Your post encapsulates about a dozen questions I've had re refurb of the pure unobtainium stuff. Printed! It's Very nice to know that, with some precise fiddling - many of these can be resurrected. (And thanks to Stan, repeatedly - for supplying the unobtainium Information!) GaAs back with a vengeance, eh? 150 Ghz might get us 5000 Channels - with nothing watchable.. Two ears and a tail - {static-free, of course} Ashton Craig Sawyers wrote: I have read postings about using some fast SchotkyI did this with a defunct S3a 1GHz sampling probe. The brige was toast |
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Re: 475A filter, protective cap availability?
Robert Morein
Lighting gels are not very thin, because they are mounted in front of
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lights, not lenses. The dye is "cast" into the material. ----- Original Message -----
From: "Miroslav Pokorni" <mpokorni2000@...> To: <TekScopes@...>; "Mark Anton" <heightstv@...> Sent: Friday, March 05, 2004 3:07 AM Subject: Re: [TekScopes] 475A filter, protective cap availability? Hello Mark,what is that material and why musical instrument repair shops would have it.mounting. In that case, how you would make a 4 x 6" screen without film collapsing?repair getshop should possibly have some. The only to be careful of is not too fartherone that is too opaque. Then you would have to turn up intensity scopesthan needed to view the trace. I have used gel material on several CRTnow and works well. It isnt just for looks either...the reason it isthereis to provide a higher contrast trace. vs seeing a white background. filter with a nice sharp new one. Ar they commonly available? |
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Re: Bias batteries in 7S14
jeans
You can download the instruction Manual from TekNet at
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<>. You need to sign up but they seem to be OK. Click on the manual panel on the left of their web site and follow the instructions. You can only download 5 manuals per month. The file is large, 25 Mbytes so s fairly complete. Don Black. Michael Dunn wrote: Does anyone have a digitized manual...? |
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Re: Your document (Public Humiliation)
Ashton Brown
Yes, I'd expect that by now - most Tekscopes readers are aware of the harvesting of e-mail addresses: often via the wide-OPEN access to LookOut and M$ Office -- holes even larger than those in the OS itself. The first target often is: one's address book. This has been going on only since.. version 3.x of this humongous 'application on-top-of DOS' - ergo
Pretty likely, someone with Mr. G's address in *their* book is most apt to be the real source of the nastily tainted message. (Note too that, Yahoo strips off attachments by default) But then, with Dumont grade s/ware in millions of places: who can resist poking it with a blunt object? daveolla wrote: Greetings, Grobbins says not guilty! people always make the front page when accused, and their later innocence buried in the folds of the last pages.-----------------< snip >------------------ |
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Re: Your document (Public Humiliation)
Greetings, Grobbins says not guilty! people always make the front
page when accused, and their later innocence buried in the folds of the last pages. --- In TekScopes@..., "Howard Matthews" > Grobbins got a virus! Neener, neener, neener! To answer your allegations Mr. Neener -Norton antivirus is updated automatically, often. -Presently no viruses have been found. -No attachements have been opened since Feb 5 ( from one of our members), and it was run thru Norton, it was clean. -I also did not post anything on the site since Feb 4, message 6693. I have noticed that my full email address showed up on the post supposedly sent by me, however, none of my "real posts" have this. Mr. Neener wrote; 1. Did not have antivirus software up-to-date, ANDFor a techie to fall for one of these is embarrassing.OK, I'm sorry...... that as a techie you fell for this, but you need not be embarrassed because this group is meant to help even those that have little understanding, and since when did this "Classic Tube Scopes" group require the computer savey of 11 year olds!! We all must try to ensure our measurements are made properly for any kind of precision. The Real grobbins@n... Daveolla P.S. The real Daveolla certainly would have started his post with a friendly "Greetings", that should have been another clue! P.S.S. hold the presses, front page, above the crease, this just in.............. --- In TekScopes@..., grobbins@n... wrote:Please have a look at the attached file. |
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ligthing gel
Craig Sawyers
You did mention that lighting gel before, but I still do notLighting gel is the stuff that is used in front of stage lighting in threatres and film sets. It is available in very many colours, in large sheets, and is heat resisting. It is thinner than the plastic sheet used in front of Tek scopes for sure - but it would certainly be better than nothing. Something like this looks about right for the standard blue 7000 series 'scope filter. Craig |
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