A good digital oscilloscope?
in [Design]
|
From: John Larkin on 8 Dec 2009 16:21 On Tue, 8 Dec 2009 12:32:52 -0600, "Tim Williams" <tmoranwms(a)charter.net> wrote: >"John Larkin" <jjlarkin(a)highNOTlandTHIStechnologyPART.com> wrote in message >news:oh6th5903d58sogu3cj8vk3er6r6li9m32(a)4ax.com... >> I love our TPS2024. 200 MHz, and all four channels and the trigger >> input are fully floating. Wanna clip the probe ground lead onto the >> source of a fet that's flailing 400 volts off ground? No problem. > >Tasty. > >What's C-to-ground like, is it basically a differential input (2 x 1M || >20pF) with a BNC input? > >Tim Something like 35 pF from the BNC outer to ground. I'd prefer less. But it's truly floating with pretty much infinite CMRR. I think it's a microwave-range FM signal link or something. John
From: Spehro Pefhany on 8 Dec 2009 16:37 On Tue, 08 Dec 2009 13:15:49 -0800, John Larkin <jjlarkin(a)highNOTlandTHIStechnologyPART.com> wrote: >On Tue, 08 Dec 2009 14:36:53 -0500, Spehro Pefhany ><speffSNIP(a)interlogDOTyou.knowwhat> wrote: > >>On Tue, 08 Dec 2009 10:28:27 -0800, John Larkin >><jjlarkin(a)highNOTlandTHIStechnologyPART.com> wrote: >> >>>On Mon, 7 Dec 2009 22:21:43 -0600, "Tim Williams" >>><tmoranwms(a)charter.net> wrote: >>> >>>>"Jamie" <jamie_ka1lpa_not_valid_after_ka1lpa_(a)charter.net> wrote in message >>>>news:oFhTm.36236$kY2.31856(a)newsfe01.iad... >>>>> My Tek 485 serves me well. I do have a small assortment of digital scopes >>>>> for portable use to gather basic data and road trip testing how ever, I >>>>> find that my 485 still gives me nice results at the bench as long as I >>>>> don't need live digital storage. >>>>> It's the only scope I have that I can take full advantage of my active >>>>> Fet probes when I need them. >>>> >>>>486 is on my Wish List. And 2465. Yessss, my preciousss.... >>>> >>>> >>>>Tim >>> >>>I love our TPS2024. 200 MHz, and all four channels and the trigger >>>input are fully floating. Wanna clip the probe ground lead onto the >>>source of a fet that's flailing 400 volts off ground? No problem. >>> >>>John >> >>Shame about that antediluvian CF card slot that can't write to even a >>2G card. 8-( > >Just snap a photo of the screen. > >John I ordered some cards direct from Tek, turned out they were standard (but obsolete) Sandisk 256M CF cards. I think Newark wanted $250 or something insane like that.
From: Jan Panteltje on 8 Dec 2009 17:16 On a sunny day (Tue, 08 Dec 2009 13:13:43 -0800) it happened John Larkin <jjlarkin(a)highNOTlandTHIStechnologyPART.com> wrote in <ogdth5hoo17m1fei5d6qjgqghik38bronc(a)4ax.com>: >On Tue, 08 Dec 2009 19:09:03 GMT, Jan Panteltje ><pNaonStpealmtje(a)yahoo.com> wrote: > >>On a sunny day (Tue, 08 Dec 2009 10:58:50 -0800) it happened Joerg >><invalid(a)invalid.invalid> wrote in <7o7lveF3obbsiU2(a)mid.individual.net>: >> >>>>>> ftp://panteltje.com/pub/DVD_remote_fluorescent_buttons_img_1676.jpg >>>>> Try some strontium aluminate. It's something like 10x better a light >>>>> storage thing than the old ZnS stuff. >>>>> >>>>> John >>>> >>>> The DVD remote in the above link *is* strontium aluminate, >>>> I just did the 4 minute test, >>>> http://en.wikipedia.org/wiki/Phosphorescence (scroll down) >>>> still clearly visible, not adapted eyes, also after 5 minutes. >>>> The color also matches tha tbird... >>>> They say the ZnS stuff is no longer used... >>>> The real 'hot' stuff I remember from my youth was 'radium', >>>> radium on watches, clocks, and even on some light switches. >>>> That was all no longer allowed at some point. >>> >>> >>>Back in those days watch dials would be readable all night, not nearly >>>have that much decay. That is no longer the case, no matter what fancy >>>material they use. >> >>No problem, you can have it if you want: >>Tritium: >> http://en.wikilib.com/wiki/Tritium >>Tritium watch: >> http://en.wikipedia.org/wiki/File:Tritium-watch.jpg >>Tritium alarm clock: >> http://www.ultralux.ch/de_shop.cfm?cmd=detail&id=48&pid=142¤t=1&mainkat=5 > >I put tritium lights on the tops of the bedposts in the cabin... it's >really dark up there, and you can whack yourself in the head coming >back from peeing. I had to order them from England, as I think they >are illegal in the USA. > >ftp://jjlarkin.lmi.net/Tritium.jpg > >John Yes, that is nice, but would not want to live in a place without electric lights... But it made me turn on the LED strip disco lights here :-)
From: Joerg on 8 Dec 2009 19:55 John Larkin wrote: > On Tue, 08 Dec 2009 19:09:03 GMT, Jan Panteltje > <pNaonStpealmtje(a)yahoo.com> wrote: > >> On a sunny day (Tue, 08 Dec 2009 10:58:50 -0800) it happened Joerg >> <invalid(a)invalid.invalid> wrote in <7o7lveF3obbsiU2(a)mid.individual.net>: >> >>>>>> ftp://panteltje.com/pub/DVD_remote_fluorescent_buttons_img_1676.jpg >>>>> Try some strontium aluminate. It's something like 10x better a light >>>>> storage thing than the old ZnS stuff. >>>>> >>>>> John >>>> The DVD remote in the above link *is* strontium aluminate, >>>> I just did the 4 minute test, >>>> http://en.wikipedia.org/wiki/Phosphorescence (scroll down) >>>> still clearly visible, not adapted eyes, also after 5 minutes. >>>> The color also matches tha tbird... >>>> They say the ZnS stuff is no longer used... >>>> The real 'hot' stuff I remember from my youth was 'radium', >>>> radium on watches, clocks, and even on some light switches. >>>> That was all no longer allowed at some point. >>> >>> Back in those days watch dials would be readable all night, not nearly >>> have that much decay. That is no longer the case, no matter what fancy >>> material they use. >> No problem, you can have it if you want: >> Tritium: >> http://en.wikilib.com/wiki/Tritium >> Tritium watch: >> http://en.wikipedia.org/wiki/File:Tritium-watch.jpg >> Tritium alarm clock: >> http://www.ultralux.ch/de_shop.cfm?cmd=detail&id=48&pid=142¤t=1&mainkat=5 > > I put tritium lights on the tops of the bedposts in the cabin... it's > really dark up there, and you can whack yourself in the head coming > back from peeing. I had to order them from England, as I think they > are illegal in the USA. > Doesn't seem to be illegal, I have a Chase-Durer watch similar to this one: http://www.amazon.com/Chase-Durer-Blackhawk-Mach-3/dp/B000X1X5EO Those are American watches, I didn't import it. But IMHO its tritium illumination still ain't as good as the stuff from the olden days. > ftp://jjlarkin.lmi.net/Tritium.jpg > Nice. But one thrashing with the bed sheets and ... chop ... thwack. I'd probably have gone with a recessed LED blinkenlight that barely sticks out above the post. I once did a test with a uC operating a strobe (like you see on aircraft) and played with the timer values. It's amazing how miniscule a duty cycle the human eye recognizes when it's dark. Even when I put a PWM-ramp in so it doesn't irritate much. -- Regards, Joerg http://www.analogconsultants.com/ "gmail" domain blocked because of excessive spam. Use another domain or send PM.
From: krw on 8 Dec 2009 19:58
On Tue, 08 Dec 2009 14:36:53 -0500, Spehro Pefhany <speffSNIP(a)interlogDOTyou.knowwhat> wrote: >On Tue, 08 Dec 2009 10:28:27 -0800, John Larkin ><jjlarkin(a)highNOTlandTHIStechnologyPART.com> wrote: > >>On Mon, 7 Dec 2009 22:21:43 -0600, "Tim Williams" >><tmoranwms(a)charter.net> wrote: >> >>>"Jamie" <jamie_ka1lpa_not_valid_after_ka1lpa_(a)charter.net> wrote in message >>>news:oFhTm.36236$kY2.31856(a)newsfe01.iad... >>>> My Tek 485 serves me well. I do have a small assortment of digital scopes >>>> for portable use to gather basic data and road trip testing how ever, I >>>> find that my 485 still gives me nice results at the bench as long as I >>>> don't need live digital storage. >>>> It's the only scope I have that I can take full advantage of my active >>>> Fet probes when I need them. >>> >>>486 is on my Wish List. And 2465. Yessss, my preciousss.... >>> >>> >>>Tim >> >>I love our TPS2024. 200 MHz, and all four channels and the trigger >>input are fully floating. Wanna clip the probe ground lead onto the >>source of a fet that's flailing 400 volts off ground? No problem. >> >>John > >Shame about that antediluvian CF card slot that can't write to even a >2G card. 8-( Beats waiting 3 minutes to write to floppy. |