Re: gEDA-user: Need opinion on O-scope
Hey John, Thanks for the offer and I'll let you know. I just spent a load of cash on a backrest mold that came out wrong. If you know microchip and have worked with their ICD2 I would have you take a look at some code. I'm having trouble coding a dsPIC to control an h-bridge for a cold-plate design. Thanks, Rob On Mon, Aug 25, 2008 at 8:07 PM, John Griessen [EMAIL PROTECTED] wrote: Robert Butts wrote: I found an oscilloscope on ebay HI Robert, http://cgi.ebay.com/TEKTRONIX-7844-DUAL-BEAM-OSCILLOSCOPE_W0QQitemZ180280369955QQcmdZViewItem?hash=item180280369955_trkparms=39%3A1|66%3A2|65%3A15|240%3A1318_trksid=p3286.c0.m14 I like my 7844 for comparing two traces that are fast. It is two cathode rays in one tube, and you can line up the two, (change their offset), for side by side comparing. The fact that there are two sets of controls on the mainframe is confusing though... As in vertical bay to trigger from selector A and vertical bay to trigger from selector B ... Intensity A and B... Horiz sweep bay selector A and B. There are three 7603's for sale cheap in both rack mount layout and vertical box, ( $70 to $100 shipped), but not from a engineer type seller. The one I have is down at the moment, but people on tekscopes are ready to help me debug it. 7603'sjust have three plugin bays, so they're simple to operate. NOne of the above confusions for you or your helper turning the knobs. You could buy a few as a gamble and pass along the broken ones to whoever is helping you with the physical part of using these scopes with knobs. If you are thinking of turning knobs on plugins and mainframes with a mouth stick, some of them are fairly high torque. The volts/div knobs are high torque. If you want to hire some mods made to a scope you choose, you can ask me. I am in odd jobs mode now after a bankruptcy to pay for some product development. I would rather do some Tek scope repair and checkout than remodeling work. That's closer to spending time in my lab on my ecosensory stuff than refurbishing well-off-folks's homes. ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: Need opinion on O-scope
Robert Butts wrote: It's been years so I'm asking everyones input on this scope. The 7854 is controlled by buttons and also an addon keyboard. It's a complex language of control commands to learn. Its advantage is it can use 7xxx series plugins to digitize most anything. tekscopes and tekscopes2 elists help with diagnosing problems. More plusses: * works like a plain analog scope when not digitizing * controls are familiar to many EEs. The minuses are: * 23 to 30 years out of production, so needs help sometimes and it has the longest manual of all 7xxx series scopes. * Most owners of these fix them for themselves, so * only 10MS/second * 7xxx plugins weigh 2 to 5 lbs and need adjusting occasionally * controls are unfamiliar to many young helpers. == I have a 7904a, 7844, 7603 7704 7903. The 7903 quit for no obvious reason last year and I've not debugged int yet. The 7603 was sold on ebay working, but arrived with a power supply problem after the ride. The 7704 cam free at a garage sale and has odd problems with the backplane connectors not debugged fully yet. So two out of five work and are in the lab. The others hang out on shelves and one in the attic. I love old attic stuff! = Something for you to consider is new screenless scopes that can be controlled over ethernet or some data bus with labview or generically via software. That would give you some good accessibility. Even those will cost 5X of an old Tek scope on ebay. Just buy one form a person that can and will test it and one that works. I don't think much along these lines exist yet though... John Griessen PS the 7844 and7904a are fabulous and in use, and I have probes galore for them that would have cost $10K inmore recent scope types ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: Need opinion on O-scope
Robert Butts wrote: I found an oscilloscope on ebay HI Robert, http://cgi.ebay.com/TEKTRONIX-7844-DUAL-BEAM-OSCILLOSCOPE_W0QQitemZ180280369955QQcmdZViewItem?hash=item180280369955_trkparms=39%3A1|66%3A2|65%3A15|240%3A1318_trksid=p3286.c0.m14 I like my 7844 for comparing two traces that are fast. It is two cathode rays in one tube, and you can line up the two, (change their offset), for side by side comparing. The fact that there are two sets of controls on the mainframe is confusing though... As in vertical bay to trigger from selector A and vertical bay to trigger from selector B ... Intensity A and B... Horiz sweep bay selector A and B. There are three 7603's for sale cheap in both rack mount layout and vertical box, ( $70 to $100 shipped), but not from a engineer type seller. The one I have is down at the moment, but people on tekscopes are ready to help me debug it. 7603'sjust have three plugin bays, so they're simple to operate. NOne of the above confusions for you or your helper turning the knobs. You could buy a few as a gamble and pass along the broken ones to whoever is helping you with the physical part of using these scopes with knobs. If you are thinking of turning knobs on plugins and mainframes with a mouth stick, some of them are fairly high torque. The volts/div knobs are high torque. If you want to hire some mods made to a scope you choose, you can ask me. I am in odd jobs mode now after a bankruptcy to pay for some product development. I would rather do some Tek scope repair and checkout than remodeling work. That's closer to spending time in my lab on my ecosensory stuff than refurbishing well-off-folks's homes. ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
gEDA-user: Need opinion on O-scope
I found an oscilloscope on ebay that the asuction ends tonight. At the risk of gettting someone else interested in it it's at this link: http://cgi.ebay.com/Tektronix-7854-400-Mhz-Digital-Analog-Oscilloscope_W0QQitemZ170253977697QQcmdZViewItem?hash=item170253977697_trkparms=72%3A552%7C39%3A1%7C66%3A2%7C65%3A12%7C240%3A1318_trksid=p3286.c0.m14 It's been years so I'm asking everyones input on this scope. Thanks! ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: Need opinion on O-scope
On Sun, Aug 24, 2008 at 4:02 PM, Robert Butts [EMAIL PROTECTED] wrote: I found an oscilloscope on ebay that the asuction ends tonight. At the risk of gettting someone else interested in it it's at this link: http://cgi.ebay.com/Tektronix-7854-400-Mhz-Digital-Analog-Oscilloscope_W0QQitemZ170253977697QQcmdZViewItem?hash=item170253977697_trkparms=72%3A552%7C39%3A1%7C66%3A2%7C65%3A12%7C240%3A1318_trksid=p3286.c0.m14 It's been years so I'm asking everyones input on this scope. Thanks! ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user I have the Tek 7903, so some things related to it will apply to the 7854. These are 20+ year old oscilloscopes. Expect to have to occasionally do a repair. Mine has needed it 3 times. Two were failed (shorted) tantalum caps and the other was a connector that was corroded. There are some Tektronix proprietary parts in these scopes that you will only be able to get from a parts scope. Other than all that the Tektronix 7000 series are very nice oscilloscopes. Whenever mine dies and can't be fixed, I am not quite sure if I will get another or go for a digital scope. Darrell Harmon ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: Need opinion on O-scope
Darrell Harmon wrote: On Sun, Aug 24, 2008 at 4:02 PM, Robert Butts [EMAIL PROTECTED] wrote: I found an oscilloscope on ebay that the asuction ends tonight. At the risk of gettting someone else interested in it it's at this link: http://cgi.ebay.com/Tektronix-7854-400-Mhz-Digital-Analog-Oscilloscope_W0QQitemZ170253977697QQcmdZViewItem?hash=item170253977697_trkparms=72%3A552%7C39%3A1%7C66%3A2%7C65%3A12%7C240%3A1318_trksid=p3286.c0.m14 It's been years so I'm asking everyones input on this scope. Thanks! ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user I have the Tek 7903, so some things related to it will apply to the 7854. These are 20+ year old oscilloscopes. Expect to have to occasionally do a repair. Mine has needed it 3 times. Two were failed (shorted) tantalum caps and the other was a connector that was corroded. There are some Tektronix proprietary parts in these scopes that you will only be able to get from a parts scope. Other than all that the Tektronix 7000 series are very nice oscilloscopes. Whenever mine dies and can't be fixed, I am not quite sure if I will get another or go for a digital scope. Darrell Harmon I'll second what Darrell said. I don't have that exact one, but the 7k scopes were quality units. There are a lot of plugins on the market which can offer you some nice features. For example the 7A22 plugins will get you down to 10 uV (yes, that 'u' as in 'micro') per division which can be pretty nice for some things. Really I only have 2 complaints about mine. 1) I only have about a 100 MHz one and I wish it were faster. 2) It is heavy and my tolerance for heavy things has gone down significantly over the years. I drool when I see these lunchbox sized scopes that weigh about 5 lbs! -Dan ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: Need opinion on O-scope
On Aug 24, 2008, at 8:09 PM, Dan McMahill wrote: I found an oscilloscope on ebay that the asuction ends tonight. At the risk of gettting someone else interested in it it's at this link: http://cgi.ebay.com/Tektronix-7854-400-Mhz-Digital-Analog- Oscilloscope_W0QQitemZ170253977697QQcmdZViewItem? hash=item170253977697_trkparms=72%3A552%7C39%3A1%7C66%3A2%7C65% 3A12%7C240%3A1318_trksid=p3286.c0.m14 It's been years so I'm asking everyones input on this scope. I have the Tek 7903, so some things related to it will apply to the 7854. These are 20+ year old oscilloscopes. Expect to have to occasionally do a repair. Mine has needed it 3 times. Two were failed (shorted) tantalum caps and the other was a connector that was corroded. There are some Tektronix proprietary parts in these scopes that you will only be able to get from a parts scope. Other than all that the Tektronix 7000 series are very nice oscilloscopes. Whenever mine dies and can't be fixed, I am not quite sure if I will get another or go for a digital scope. I'll second what Darrell said. I don't have that exact one, but the 7k scopes were quality units. There are a lot of plugins on the market which can offer you some nice features. For example the 7A22 plugins will get you down to 10 uV (yes, that 'u' as in 'micro') per division which can be pretty nice for some things. Really I only have 2 complaints about mine. 1) I only have about a 100 MHz one and I wish it were faster. 2) It is heavy and my tolerance for heavy things has gone down significantly over the years. I've owned a 7704 and a 7904, and currently have an R7603 (hosting a 7CT1 curve tracer) and have found them all to be great units. The 7000 series dates back to the early 1970s, and the fact that there are so many of them still out there working everyday in labs says a lot about their quality and utility. They are maintainable and readily available. There are plug-ins to suit pretty much every oscilloscope application, and even plug-ins to turn it into a curve tracer or a spectrum analyzer. Documentation (both user and service manuals) are readily available, and user support is excellent...there are even quite a few mailing lists and forums that are frequented even by some of the guys who DESIGNED those scopes. (Yahoo's TekScopes list comes to mind) You can't get support that good with current-model equipment. Really worried about it breaking and not being easily fixable? Buy two, they're cheap. A loaded one goes for ~$200...a thin one goes for half that, even less if you don't have to pay for shipping. These are scopes that cost more than cars in 1971. I drool when I see these lunchbox sized scopes that weigh about 5 lbs! Yeah, but the nice small ones are always digital oscilloscopes...completely different instrument, as you know. I've got a Tektronix TDS3012 lunchbox-sized digital scope that I love, but when things get dicey on the bench, out comes the Tek 2465A analog scope. -Dave -- Dave McGuire Port Charlotte, FL ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: Need opinion on O-scope
On Aug 24, 2008, at 6:02 PM, Robert Butts wrote: I found an oscilloscope on ebay that the asuction ends tonight. At the risk of gettting someone else interested in it it's at this link: http://cgi.ebay.com/Tektronix-7854-400-Mhz-Digital-Analog- Oscilloscope_W0QQitemZ170253977697QQcmdZViewItem? hash=item170253977697_trkparms=72%3A552%7C39%3A1%7C66%3A2%7C65% 3A12%7C240%3A1318_trksid=p3286.c0.m14 It's been years so I'm asking everyones input on this scope. I see the auction has already ended. :-( That would've been a truly fantastic scope. I'd love to have grabbed that myself! It even had the waveform calc module. I'm drooling here! -Dave -- Dave McGuire Port Charlotte, FL ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
