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Re: For your consideration
He is from the UK after all. I think you cut him some slack just based on
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on the issues he's had with the car he's restoring! He's sounds like a very interesting chap and it's nice to have some diversity here. I agree with Craig. Don't be such snobs... -----Original Message-----
From: Craig Sawyers [mailto:c.sawyers@...] Sent: Sunday, March 07, 2004 10:40 AM To: Tekscopes Subject: RE: [TekScopes] For your consideration Importance: High > No, no, Fred. Those differently-literate people serve an > important purpose: Hey - c'mon you guys! If I'd joined the list having got hold of a 549 storage scope, and everyone got anal with me about the way I spelt a damned word, I'd be off like a shot and good riddance!! Cut the guy some slack, OK? Craig Yahoo! Groups Sponsor ADVERTISEMENT ---------------------------------------------------------------------------- -- 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: For your consideration
Craig Sawyers
No, no, Fred. Those differently-literate people serve anHey - c'mon you guys! If I'd joined the list having got hold of a 549 storage scope, and everyone got anal with me about the way I spelt a damned word, I'd be off like a shot and good riddance!! Cut the guy some slack, OK? Craig |
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Re: For your consideration
John Miles
No, no, Fred. Those differently-literate people serve an important purpose:
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to supply cheap equipment to the rest of us! After all, "Tectronics" gear can be had dirt cheap on eBay compared to "Tektronix" gear, because nobody can find it in their search engine. -- jm
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Where do these plugins fit ?
Peter
I can get for nearly free ( 5 Euro = USD 6.50 per pc ) some scopes
and plug ins : 3S76 3T77A 3T4 3S2 as well as the scopes RM564 ( incl. 3S2 and 3T2 ) and a RM561A ( incl. 3S1 and 3T2 ). Do all these plugins fit in either scope ? Where to find specs on the internet ? ( I found a wealth on info on the 7000 series and the 7xyz plug ins but not for the said 3xyz plugin series ). Thanks for any help. Peter PE1ECM |
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If mail to me bounces...
Fellow Tekkers,
Please be aware that, when trying to E-mail me directly, our domain's spam filters have been known to get overzealous. I can and will 'whitelist' individual addresses, but I can't do it if I don't know that you tried to get through (and subsequently got bounced). If your mail attempt to me does bounce, please try posting a brief note to me here. That will cue me to take a hard look at the reject log, and see if I can find where things went wrong. Also, please keep in mind that a bounce is NEVER directed at anyone personally, and they should not be taken personally. The IP ranges I block are directed solely at abusive ISPs who, for whatever reason, have chosen not to address their infestations of spammers and other network abusers. Thanks much. -=-=-=-=-=-=-=-=-=-=-=- Bruce Lane, Owner & Head Hardware Heavy, Blue Feather Technologies -- kyrrin (at) bluefeathertech do/t c=o=m "If Salvador Dali had owned a computer, would it have been equipped with surreal ports?" |
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Re: New file posted
Greyhawk
I Would Send You Some Files, But All Your E-Mail Addresses Bounce.
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Greyhawk ----- Original Message -----
From: Bruce Lane To: tekscopes@... Sent: Saturday, March 06, 2004 22:49 Subject: [TekScopes] New file posted With thanks to Fred de Vries, I've posted a ZIPfile containing EPROM images for the devices in the 7D20. They're version 81.1, F1.03. Filename is 7d20.zip at the usual location and path. Contributions always welcome! ;-) -=-=-=-=-=-=-=-=-=-=-=- Bruce Lane, Owner & Head Hardware Heavy, Blue Feather Technologies -- kyrrin (at) bluefeathertech do/t c=o=m "If Salvador Dali had owned a computer, would it have been equipped with surreal ports?" Yahoo! Groups Sponsor ADVERTISEMENT ------------------------------------------------------------------------------ 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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Advice wanted first time servicing a scope Techronics 549
Christian
Dear Friends
I have a small collection of test equipment and recently been donated a Techtronics 549 storage oscilloscope. The unit has had little use but many years of storage makes me think a tune up is in order. Can anybody please help me with service manual and operating instruction. The display screen makes a very good alternative to a lava lamp but not so good for storage of a waveform. So far I have done a few essential safety test and powered up the scope. The circuit boards have many small neon tubes on them. Are these being used as some kind of voltage regulator I have not seen this before ? My knowledge of scopes really only extends to using them, any advice for cleaning up the scope and servicing it and any known bugs with this scope. The unit also has the fan guard missing off the back and a broken selector switch. Can anybody help me with spares. I have some pictures of the scope and my other items. Please visit my site and look at the museum and bench view pages. Best regards Christian Fletcher. www.christianfletcher.org |
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Re: lethality of HV
In message <051a01c4034e$adc5cb90$0300a8c0@LianLi>, Robert Morein <morepub@...> writes
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.Well he should be cautious. Isn't the point here that it isn't just the static charge on the scope we are talking about but the capability of the PSU to deliver as no matter how small the energy charge that the tube will hold I'll bet you a pound to a penny that the PSU has more than enough oomph to kill you. I don't blame him. It scares me too. To the point that I have a number of separate meters to dangle round stuff before I power it up (when it is very high volts) so I don't have to dab round any more than necessary. Paranoia I know but there's only one of me and components are easily replaced. Robin It is my understanding that this voltage is not lethal, primarily because the CRT is too small to store a lethal charge.-- Robin Birch |
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Re: Oscilloscopes 101 - eBay
Craig Sawyers
-- whereasMy favourite is the Tek 111 pretrigger pulse generator. This is an avalanche pulser, and gives a really clean 400ps rise time. Since it has an adjustable delay between a pretrigger pulse and the main output you can kick a timebase into action well in advance of the main event. This is OK for testing things using a 7T11/7S11/S1 set up with 1GHz bandwidth (using sum of squares). Or (and I haven't tried this) use the 400ps edge to trigger a tunnel diode pulser to generate a really fast event, but with an adjustable pretrigger. Craig |
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Re: lethality of HV
Craig Sawyers
Bet that would blow the gate on a MOSFET ;-)
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Craig -----Original Message-----
From: Rex W. Athey [mailto:mister_twister@...] Sent: 07 March 2004 02:26 To: TekScopes@...; Craig Sawyers Subject: Re: [TekScopes] lethality of HV Speaking of High Voltage - check this out.... and the explanation..... DEFINITELY LETHAL!!!!!!!!! |
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4xx Portable Feet Repros Available
OK folks,
I think I have the process in pretty good control. I am willing to cast some replacement feet for 453, 454, -A, 464, and I think they also fit the 465, 475, 485 series of scopes. (These are the bottom feet, not the rear feet!) I cannot do a lot. I can cast and cure one set of 4 feet per day, if I'm not distracted by something else. I'm not doing this for any profit, just to help some of you fellow Tek junkies. And to recoup some of my $75 investment in casting chems. To see what the recast feet look like, please see: These are pretty close reproductions of Tek part 348-0080-00 or - 01. The original models are unused NOS that Stan provided. The rubber is a little softer than the originals, and quite a bit blacker. A quick abrasion test with 200 grit sandpaper indicates they are about as abrasion resistant as the originals. They are more suseptable to cuts, though. Very, very usable, but not 100% authentic. Replace the entire set of 4 if you want to resell the scope, due to the noticable color difference. The deal would be - $6.00 (that is $5.00 and about $1.00 S&H) plus a set of nuts (alloy inserts) that I can use for the next set of 4 feet. I would also consider 2 sets of the nuts plus $1.00 S&H for one set of repros. If anyone is interested, please contact me here first. Good scoping, -Howard |
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New file posted
With thanks to Fred de Vries, I've posted a ZIPfile containing EPROM images for the devices in the 7D20. They're version 81.1, F1.03.
Filename is 7d20.zip at the usual location and path. Contributions always welcome! ;-) -=-=-=-=-=-=-=-=-=-=-=- Bruce Lane, Owner & Head Hardware Heavy, Blue Feather Technologies -- kyrrin (at) bluefeathertech do/t c=o=m "If Salvador Dali had owned a computer, would it have been equipped with surreal ports?" |
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Re: Oscilloscopes 101 - eBay
Ashton Brown
Have seen some unbuilt Heathkits (scopes and other pretty trivial gadgets) go for astronomical prices, though I'm not not looking often now. Ego-bid war between two will do it: $900 IIRC, and several >500.
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People will also pay lots for Heath's earlier (green case) calibrator, with not very impressive specs; unuseable for fast Tr check. -- whereas one of their last new kits created, the Model IG-4244: beats out Tek's and HP's expensive spread, while also providing a clean typ. 700 pSec Tr into 50 ohms. Not a 284, but plenty fine for sum-squares verification to 350 MHz. These have occasionally shown up and slipped through the cracks - I bought a spare for my hand-assembled one for ~$50. 'Course too, *cough* one of those Warz got me ~$420 for a Tek 453! (admittedly pristine, calibrated, photographed Tr.) in about '00 or '01. Call it Psych 101A? {cackle} Ashton Tony Denning wrote: It pays to research...must be someone new to the hobby. This is probably the highest bid I've ever seen on a older service grade EICO 460 scope (C$230!) and no guarantee it even works. Could have any number of nice Tek models for this price. Anyway, the seller must be happy... |
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Re: lethality of HV
Ironically it was at Siemens where I was working for when one fellow got
electrocuted. It seems he grabbed on to a 480VAC 3 phase buss while pulling himself up from underneath a linear accelerator. Instant death. Good point about being tired. It's best to come back another day. I have worked for many companies that had the "2 man rule". Of course nothing could save you from 480V 3 phase. A little fear, like fear of God is healthy - respect a requirement. |
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Re: lethality of HV
Twenty years ago, when I worked for Siemens in Munich, after hours, if there
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was no one in the lab we were not allowed to work with anything electrical, that included 5 V lab supply, soldering iron etc. We used to joke that in such circumstances we should put a seat belt while seating in desk chair, in case that someone falls asleep, falls out of chair and gets hurt, but we were only our thirties, still feeling immortal. Regards Miroslav Pokorni ----- Original Message -----
From: "Greyhawk" <greyhawkeng@...> To: <TekScopes@...>; "Fred Olsen" <fwolsen@...> Sent: Saturday, March 06, 2004 11:40 AM Subject: Re: [TekScopes] lethality of HV I Was Working On A High Energy Strobe System On The Bench, Late At Night26 Years Ago Using A 500v Regulated Supply, I Was Tired, And Had The Supply Set To Max Current, And Voltage. Being Tired, I Had The Single Meter Set To Current (Thought 0 Volts), Clipped The Ground Lead To The PCB, And Held Onto The Ground Lead To Steady The PCB, And Grabbed The Positive Lead. At Full Voltage, And 500 Mils For A Minute (A Lead In Each Hand), After Getting My Thoughts To What Was Happening (Very Difficult Under The Present Circumstances)Stood Up And Walked Backwards, And Pulled The Leads Out. The Doctor Said I Should Have Been Dead On The Spot. I Guess The Great Spirit Was On My Side That Night. I Hope No One Here Has To Learn The Hard Way As I Did, Not Only Should Safety Be A Concern, But Mental Awareness, And Another Person In The Vicinity (In Case). Also. As You Get Tired, Dangerous Mistakes Are Made. I Still Have The Scars On Both Hands 26 Years Later As A Reminder Of My Stupidity. ---- Yahoo! Groups LinksService. |
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Re: lethality of HV
Brian Goldsmith
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----- Original Message -----
From: "Greyhawk" I Was Working On A High Energy Strobe System On The Bench, Late At Night 26 Years Ago Using A 500v Regulated Supply, -- Also. As You Get Tired, Dangerous Mistakes Are Made. I Still Have The Scars On Both Hands 26 Years Later As A Reminder Of My Stupidity. **** Is that why the Shift key gets depressed for each word that is typed? Brian Goldsmith. |
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Re: lethality of HV
One of the better (and readily available) devices to painlessly dissipate
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static charge is a quarter coin. I hold on the most of the surface of the coin and touch grounded surface with exposed part of coin. That way, discharge current gets distributed over larger skin area and I do not feel it as a shock, as a matter of fact, do not feel it at all. Regards Miroslav Pokorni ----- Original Message -----
From: "Gary Allsebrook" <regman10@...> To: "Craig Sawyers" <c.sawyers@...>; <TekScopes@...> Sent: Saturday, March 06, 2004 8:44 AM Subject: RE: [TekScopes] lethality of HV Some components like JFETS can be damaged at potentials under 100V.MOSFET is even more sensitive, junction can take more abuse than oxide layer at gate of transistor. Regards Miroslav Pokorni |
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Re: lethality of HV
Greyhawk
I Was Working On A High Energy Strobe System On The Bench, Late At Night 26 Years Ago Using A 500v Regulated Supply, I Was Tired, And Had The Supply Set To Max Current, And Voltage. Being Tired, I Had The Single Meter Set To Current (Thought 0 Volts), Clipped The Ground Lead To The PCB, And Held Onto The Ground Lead To Steady The PCB, And Grabbed The Positive Lead. At Full Voltage, And 500 Mils For A Minute (A Lead In Each Hand), After Getting My Thoughts To What Was Happening (Very Difficult Under The Present Circumstances)Stood Up And Walked Backwards, And Pulled The Leads Out. The Doctor Said I Should Have Been Dead On The Spot. I Guess The Great Spirit Was On My Side That Night. I Hope No One Here Has To Learn The Hard Way As I Did, Not Only Should Safety Be A Concern, But Mental Awareness, And Another Person In The Vicinity (In Case). Also. As You Get Tired, Dangerous Mistakes Are Made. I Still Have The Scars On Both Hands 26 Years Later As A Reminder Of My Stupidity.
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Greyhawk ----- Original Message -----
From: Fred Olsen To: TekScopes@... Sent: Saturday, March 06, 2004 14:15 Subject: Re: [TekScopes] lethality of HV Robert Morein wrote: > A friend of mine is afraid to work on ... 24 KV. > Comments? War stories aside for a moment, I think the essence of the question is "afraid". It's my non-humble opinion that his fear is born of inexperience at that level, perhaps also a lack of proper training, and is therefore a 'good thing'. In such situations it's quite common for someone to make a mistake due to the distraction caused by their fear. I would submit that if your friend has no means (or need) to acquire the training, then the experience, which would change the fear to a rational respect - then he has no business messing about where he shouldn't and needs to have it done for him. He's not silly, he's not a coward; he's being quite sensible. Certain situations don't allow for mistakes - not even one. I also have practiced 'one hand only' around high voltage, for something like .......... years. (Hmmm. Where in the world did those number keys go?) Always careful, and I still have the marks to show the effects of an unexpected breakdown, or of waiting six months for an RF burn to heal, or simply of a lapse in concentration. Yes, Craig, we're old. ;<)) Fred -- <>< -- Outgoing checked by Norton AV Yahoo! Groups Sponsor ADVERTISEMENT ------------------------------------------------------------------------------ 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. |
Bruce Lane
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