Question for old-timers re: Simpson meters
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From: Dave M on 15 Jan 2010 21:00 Jim Yanik wrote: > "Mark Zacharias" <mark_zacharias(a)sbclobal.net> wrote in > news:00c8f14f$0$1584$c3e8da3(a)news.astraweb.com: > >> "Jim Yanik" <jyanik(a)abuse.gov> wrote in message >> news:Xns9D005EBA3EB83jyaniklocalnetcom(a)216.168.3.44... >>> "Mark Zacharias" <mark_zacharias(a)sbclobal.net> wrote in >>> news:003beb0d$0$2118$c3e8da3(a)news.astraweb.com: >>> >>>> Hi, >>>> >>>> As some of the guys here know, I presently collect old analog >>>> multimeters. >>>> >>>> I recall a picture I saw several years ago of a "wall" of Simpson >>>> meters - maybe 50 or more, used to demonstrate reliability. They >>>> were all being pulsed with DC of perhaps 0.5 hz or so for years on >>>> end and none had failed. >>> >>> that's not surprising; >>> the meter movements are very simple and sealed from contamination. >>> there's not much to fail,especially if you're not transporting them. >>> >>> the batteries leaking or resistors going out of tolerance are the >>> biggest problems with Simpson meters,aside from being dropped. >>>> >>>> Anybody remember this and where can I get a JPG of this, and maybe >>>> a link to the info? >>>> >>>> I've tried Google images etc no luck. >>>> >>>> >>>> Mark Z. >>>> >>>> -- >>> Jim Yanik >>> jyanik >>> at >>> localnet >>> dot com >> >> >> Not surprising except perhaps considering mechanical issues - >> bearings, solder - to-coil connections, spring and/or taut-band >> failure, etc. As I recall, they were running this way for maybe over >> 20 years. >> >> They may have been naked meter movements and not complete VOM's. >> >> Like to have that picture, though... >> >> Mark Z. >> >> > > those meters on the wall were likely left in one switch position and > thus not any different than a "naked meter movement" with a resistor > in series to measure voltage instead of current. > > BTW,I still have my Simpson 270-3 VOM. Works great. I, too, still have my 260-3 that I bought from Allied Electronics in 1965, while serving in the Navy. It's not totally original, since I replaced the original meter movement in the late 60s with a taut band movement from a damaged instrument, and later selected the range resistors to improve the accuracy. Since then, it has served flawlessly, and on the last calibration, was still +/- 1% on all DC voltage and current ranges. AC and resistance ranges were a bit less accurate, but still well within specs. In all, it was $65 well spent.. -- David dgminala at mediacombb dot net
From: Mark Zacharias on 16 Jan 2010 05:33 "Jim Yanik" <jyanik(a)abuse.gov> wrote in message news:Xns9D0156C3ADDA4jyaniklocalnetcom(a)216.168.3.44... > "Mark Zacharias" <mark_zacharias(a)sbclobal.net> wrote in > news:00c8f14f$0$1584$c3e8da3(a)news.astraweb.com: > >> "Jim Yanik" <jyanik(a)abuse.gov> wrote in message >> news:Xns9D005EBA3EB83jyaniklocalnetcom(a)216.168.3.44... >>> "Mark Zacharias" <mark_zacharias(a)sbclobal.net> wrote in >>> news:003beb0d$0$2118$c3e8da3(a)news.astraweb.com: >>> >>>> Hi, >>>> >>>> As some of the guys here know, I presently collect old analog >>>> multimeters. >>>> >>>> I recall a picture I saw several years ago of a "wall" of Simpson >>>> meters - maybe 50 or more, used to demonstrate reliability. They >>>> were all being pulsed with DC of perhaps 0.5 hz or so for years on >>>> end and none had failed. >>> >>> that's not surprising; >>> the meter movements are very simple and sealed from contamination. >>> there's not much to fail,especially if you're not transporting them. >>> >>> the batteries leaking or resistors going out of tolerance are the >>> biggest problems with Simpson meters,aside from being dropped. >>>> >>>> Anybody remember this and where can I get a JPG of this, and maybe a >>>> link to the info? >>>> >>>> I've tried Google images etc no luck. >>>> >>>> >>>> Mark Z. >>>> >>>> >>> >>> >>> >>> -- >>> Jim Yanik >>> jyanik >>> at >>> localnet >>> dot com >> >> >> Not surprising except perhaps considering mechanical issues - >> bearings, solder - to-coil connections, spring and/or taut-band >> failure, etc. As I recall, they were running this way for maybe over >> 20 years. >> >> They may have been naked meter movements and not complete VOM's. >> >> Like to have that picture, though... >> >> Mark Z. >> >> > > those meters on the wall were likely left in one switch position and thus > not any different than a "naked meter movement" with a resistor in series > to measure voltage instead of current. > > BTW,I still have my Simpson 270-3 VOM. Works great. > > -- > Jim Yanik > jyanik > at > localnet > dot com I have a 270-2 and it's one of my favorites. Just a "no-bull***t" meter that just does it's job, and is deadly accurate. One thing I really like about it is the meter ballistics. Readings are quick, but with no overshoot and virtually no "settling down" time. My AVO's for example are really nice and accurate but much slower to get a reading. As collectors pieces or occasional use it's not a problem but in everyday shop use the faster readings are a blessing. My other Simpsons include a 260-6P, a 260 XLPM, a 635 Bach-Simpson, and a 303 VTVM. Several are featured as guest meters at simpson260.com. Mark Z.
From: Mark Zacharias on 16 Jan 2010 05:57 "Dave M" <dgminala4444(a)mediacombb.net> wrote in message news:LcydnZhaWvohgMzWnZ2dnUVZ_o2dnZ2d(a)giganews.com... > Jim Yanik wrote: >> "Mark Zacharias" <mark_zacharias(a)sbclobal.net> wrote in >> news:00c8f14f$0$1584$c3e8da3(a)news.astraweb.com: >> >>> "Jim Yanik" <jyanik(a)abuse.gov> wrote in message >>> news:Xns9D005EBA3EB83jyaniklocalnetcom(a)216.168.3.44... >>>> "Mark Zacharias" <mark_zacharias(a)sbclobal.net> wrote in >>>> news:003beb0d$0$2118$c3e8da3(a)news.astraweb.com: >>>> >>>>> Hi, >>>>> >>>>> As some of the guys here know, I presently collect old analog >>>>> multimeters. >>>>> >>>>> I recall a picture I saw several years ago of a "wall" of Simpson >>>>> meters - maybe 50 or more, used to demonstrate reliability. They >>>>> were all being pulsed with DC of perhaps 0.5 hz or so for years on >>>>> end and none had failed. >>>> >>>> that's not surprising; >>>> the meter movements are very simple and sealed from contamination. >>>> there's not much to fail,especially if you're not transporting them. >>>> >>>> the batteries leaking or resistors going out of tolerance are the >>>> biggest problems with Simpson meters,aside from being dropped. >>>>> >>>>> Anybody remember this and where can I get a JPG of this, and maybe >>>>> a link to the info? >>>>> >>>>> I've tried Google images etc no luck. >>>>> >>>>> >>>>> Mark Z. >>>>> >>>>> -- >>>> Jim Yanik >>>> jyanik >>>> at >>>> localnet >>>> dot com >>> >>> >>> Not surprising except perhaps considering mechanical issues - >>> bearings, solder - to-coil connections, spring and/or taut-band >>> failure, etc. As I recall, they were running this way for maybe over >>> 20 years. >>> >>> They may have been naked meter movements and not complete VOM's. >>> >>> Like to have that picture, though... >>> >>> Mark Z. >>> >>> >> >> those meters on the wall were likely left in one switch position and >> thus not any different than a "naked meter movement" with a resistor >> in series to measure voltage instead of current. >> >> BTW,I still have my Simpson 270-3 VOM. Works great. > > I, too, still have my 260-3 that I bought from Allied Electronics in 1965, > while serving in the Navy. It's not totally original, since I replaced > the original meter movement in the late 60s with a taut band movement from > a damaged instrument, and later selected the range resistors to improve > the accuracy. Since then, it has served flawlessly, and on the last > calibration, was still +/- 1% on all DC voltage and current ranges. AC > and resistance ranges were a bit less accurate, but still well within > specs. > In all, it was $65 well spent.. > > -- > David > dgminala at mediacombb dot net > > > Models 260-3 and later have internal adjustments which can obtain accuracy to a very high degree. The 10 volt range suffers a bit at full scale but I adjust mine for best accuracy in the 5 to 5.6 volt range, where small differences can be huge in modern equipment. Sometimes you just have to use a good digital meter though, and I have several of them as well. Yamaha receivers use protection circuits where the difference between 1.2 and 1.4 volts, for example, can be critical. Trouble is we often take the readings of a digital as "gospel". Recently a co-workers' cheap digital was discovered to have approximately a 50% error when we were reading a Vsus line in a plasma. We were trying to find why the reading was 295 volts instead of the desired 195. After trying a different power supply board, it was discovered the multimeter had come up lame. Mark Z.
From: Jamie on 16 Jan 2010 10:19 Mark Zacharias wrote: > "Dave M" <dgminala4444(a)mediacombb.net> wrote in message > news:LcydnZhaWvohgMzWnZ2dnUVZ_o2dnZ2d(a)giganews.com... > >> Jim Yanik wrote: >> >>> "Mark Zacharias" <mark_zacharias(a)sbclobal.net> wrote in >>> news:00c8f14f$0$1584$c3e8da3(a)news.astraweb.com: >>> >>>> "Jim Yanik" <jyanik(a)abuse.gov> wrote in message >>>> news:Xns9D005EBA3EB83jyaniklocalnetcom(a)216.168.3.44... >>>> >>>>> "Mark Zacharias" <mark_zacharias(a)sbclobal.net> wrote in >>>>> news:003beb0d$0$2118$c3e8da3(a)news.astraweb.com: >>>>> >>>>>> Hi, >>>>>> >>>>>> As some of the guys here know, I presently collect old analog >>>>>> multimeters. >>>>>> >>>>>> I recall a picture I saw several years ago of a "wall" of Simpson >>>>>> meters - maybe 50 or more, used to demonstrate reliability. They >>>>>> were all being pulsed with DC of perhaps 0.5 hz or so for years on >>>>>> end and none had failed. >>>>> >>>>> >>>>> that's not surprising; >>>>> the meter movements are very simple and sealed from contamination. >>>>> there's not much to fail,especially if you're not transporting them. >>>>> >>>>> the batteries leaking or resistors going out of tolerance are the >>>>> biggest problems with Simpson meters,aside from being dropped. >>>>> >>>>>> >>>>>> Anybody remember this and where can I get a JPG of this, and maybe >>>>>> a link to the info? >>>>>> >>>>>> I've tried Google images etc no luck. >>>>>> >>>>>> >>>>>> Mark Z. >>>>>> >>>>>> -- >>>>> >>>>> Jim Yanik >>>>> jyanik >>>>> at >>>>> localnet >>>>> dot com >>>> >>>> >>>> >>>> Not surprising except perhaps considering mechanical issues - >>>> bearings, solder - to-coil connections, spring and/or taut-band >>>> failure, etc. As I recall, they were running this way for maybe over >>>> 20 years. >>>> >>>> They may have been naked meter movements and not complete VOM's. >>>> >>>> Like to have that picture, though... >>>> >>>> Mark Z. >>>> >>>> >>> >>> those meters on the wall were likely left in one switch position and >>> thus not any different than a "naked meter movement" with a resistor >>> in series to measure voltage instead of current. >>> >>> BTW,I still have my Simpson 270-3 VOM. Works great. >> >> >> I, too, still have my 260-3 that I bought from Allied Electronics in >> 1965, while serving in the Navy. It's not totally original, since I >> replaced the original meter movement in the late 60s with a taut band >> movement from a damaged instrument, and later selected the range >> resistors to improve the accuracy. Since then, it has served >> flawlessly, and on the last calibration, was still +/- 1% on all DC >> voltage and current ranges. AC and resistance ranges were a bit less >> accurate, but still well within specs. >> In all, it was $65 well spent.. >> >> -- >> David >> dgminala at mediacombb dot net >> >> >> > > Models 260-3 and later have internal adjustments which can obtain > accuracy to a very high degree. The 10 volt range suffers a bit at full > scale but I adjust mine for best accuracy in the 5 to 5.6 volt range, > where small differences can be huge in modern equipment. > Sometimes you just have to use a good digital meter though, and I have > several of them as well. Yamaha receivers use protection circuits where > the difference between 1.2 and 1.4 volts, for example, can be critical. > > Trouble is we often take the readings of a digital as "gospel". Recently > a co-workers' cheap digital was discovered to have approximately a 50% > error when we were reading a Vsus line in a plasma. We were trying to > find why the reading was 295 volts instead of the desired 195. After > trying a different power supply board, it was discovered the multimeter > had come up lame. > > Mark Z. You're suppose to calibrate analog scales at 75% of their deflection.
From: Mark Zacharias on 16 Jan 2010 16:57
"Jamie" <jamie_ka1lpa_not_valid_after_ka1lpa_(a)charter.net> wrote in message news:1xk4n.6308$%P5.991(a)newsfe21.iad... > Mark Zacharias wrote: > >> "Dave M" <dgminala4444(a)mediacombb.net> wrote in message >> news:LcydnZhaWvohgMzWnZ2dnUVZ_o2dnZ2d(a)giganews.com... >> >>> Jim Yanik wrote: >>> >>>> "Mark Zacharias" <mark_zacharias(a)sbclobal.net> wrote in >>>> news:00c8f14f$0$1584$c3e8da3(a)news.astraweb.com: >>>> >>>>> "Jim Yanik" <jyanik(a)abuse.gov> wrote in message >>>>> news:Xns9D005EBA3EB83jyaniklocalnetcom(a)216.168.3.44... >>>>> >>>>>> "Mark Zacharias" <mark_zacharias(a)sbclobal.net> wrote in >>>>>> news:003beb0d$0$2118$c3e8da3(a)news.astraweb.com: >>>>>> >>>>>>> Hi, >>>>>>> >>>>>>> As some of the guys here know, I presently collect old analog >>>>>>> multimeters. >>>>>>> >>>>>>> I recall a picture I saw several years ago of a "wall" of Simpson >>>>>>> meters - maybe 50 or more, used to demonstrate reliability. They >>>>>>> were all being pulsed with DC of perhaps 0.5 hz or so for years on >>>>>>> end and none had failed. >>>>>> >>>>>> >>>>>> that's not surprising; >>>>>> the meter movements are very simple and sealed from contamination. >>>>>> there's not much to fail,especially if you're not transporting them. >>>>>> >>>>>> the batteries leaking or resistors going out of tolerance are the >>>>>> biggest problems with Simpson meters,aside from being dropped. >>>>>> >>>>>>> >>>>>>> Anybody remember this and where can I get a JPG of this, and maybe >>>>>>> a link to the info? >>>>>>> >>>>>>> I've tried Google images etc no luck. >>>>>>> >>>>>>> >>>>>>> Mark Z. >>>>>>> >>>>>>> -- >>>>>> >>>>>> Jim Yanik >>>>>> jyanik >>>>>> at >>>>>> localnet >>>>>> dot com >>>>> >>>>> >>>>> >>>>> Not surprising except perhaps considering mechanical issues - >>>>> bearings, solder - to-coil connections, spring and/or taut-band >>>>> failure, etc. As I recall, they were running this way for maybe over >>>>> 20 years. >>>>> >>>>> They may have been naked meter movements and not complete VOM's. >>>>> >>>>> Like to have that picture, though... >>>>> >>>>> Mark Z. >>>>> >>>>> >>>> >>>> those meters on the wall were likely left in one switch position and >>>> thus not any different than a "naked meter movement" with a resistor >>>> in series to measure voltage instead of current. >>>> >>>> BTW,I still have my Simpson 270-3 VOM. Works great. >>> >>> >>> I, too, still have my 260-3 that I bought from Allied Electronics in >>> 1965, while serving in the Navy. It's not totally original, since I >>> replaced the original meter movement in the late 60s with a taut band >>> movement from a damaged instrument, and later selected the range >>> resistors to improve the accuracy. Since then, it has served >>> flawlessly, and on the last calibration, was still +/- 1% on all DC >>> voltage and current ranges. AC and resistance ranges were a bit less >>> accurate, but still well within specs. >>> In all, it was $65 well spent.. >>> >>> -- >>> David >>> dgminala at mediacombb dot net >>> >>> >>> >> >> Models 260-3 and later have internal adjustments which can obtain >> accuracy to a very high degree. The 10 volt range suffers a bit at full >> scale but I adjust mine for best accuracy in the 5 to 5.6 volt range, >> where small differences can be huge in modern equipment. >> Sometimes you just have to use a good digital meter though, and I have >> several of them as well. Yamaha receivers use protection circuits where >> the difference between 1.2 and 1.4 volts, for example, can be critical. >> >> Trouble is we often take the readings of a digital as "gospel". Recently >> a co-workers' cheap digital was discovered to have approximately a 50% >> error when we were reading a Vsus line in a plasma. We were trying to >> find why the reading was 295 volts instead of the desired 195. After >> trying a different power supply board, it was discovered the multimeter >> had come up lame. >> >> Mark Z. > You're suppose to calibrate analog scales at 75% of their deflection. > > > That's a pretty general statement... but sounds like a good idea in many cases. I have an RCA WV-38A one adjustment of which is for 1 mA full scale. Mark Z. |