Re: [volt-nuts] Banana jack shorting straps
Hmm, it appears that is true. I've just checked on both my 3456 and 3457 and they do indeed have a larger horizontal spacing. Interestingly, the spacing on the 3456 is slightly smaller than on the 3457. Met vriendelijke groet, Rob Klein verstuurd vanaf mijn smartphone Op 9 nov. 2017 19:48, om 19:48, Randy Evans schreef: >I believe that the Fluke shorting system has 3/4" spacing both >vertically >and horizontally, which is not compatible with the 3458 (I couldn't >find a >spec but visually it looks identically in both dimensions in the >photos). >The 3458 spacing is slightly greater than 3/4' horizontally. > >On Thu, Nov 9, 2017 at 10:14 AM, Rob Klein >wrote: > >> You gentlemen are aware that these things are available from Fluke at >a >> fairly reasonable price? >> >> http://nl.farnell.com/fluke/fluke-884x-short/lead-test-4- >> wire-fluke-884x-short/dp/1274092 >> >> >> Met vriendelijke groet, >> Rob Klein >> >> verstuurd vanaf mijn smartphone >> >> Op 9 nov. 2017 14:12, om 14:12, "David C. Partridge" < >> david.partri...@perdrix.co.uk> schreef: >> >Mark >> > >> >I'm trying to imagine what you are describing - is this PCBs with >4mm >> >banana plugs installed or a small PCB with two slots at 3/4" centres >to >> >match the socket spacing? >> > >> >If the latter is this intended to cover just two sockets or to short >> >all four Force and Sense sockets together (if arranged like a >3458A)? >> > >> >Thanks >> >Dave >> > >> >-Original Message- >> >From: volt-nuts [mailto:volt-nuts-boun...@febo.com] On Behalf Of >Mark >> >Sims >> >Sent: 09 November 2017 02:14 >> >To: volt-nuts@febo.com >> >Subject: [volt-nuts] Banana jack shorting straps >> > >> >The main use of these would be shorting sense to drive jacks. They >> >could also be used for input shorts. The advantage over bare copper >> >would be the ENIG gold finish... bare copper quickly forms oxide >layers >> >and copper oxide has a horrible thermal EMF. Granted, ENIG gold >> >basically involves waving a bar of gold over the plating tank and >> >hoping some gold atoms fall off. The board house I use deposits a >> >thicker layer than most. You don't want to know what "hard gold" >> >finish would cost. >> > >> >Using a PCB house to fab them is probably 20 times less expensive >than >> >having a machine shop do them out of solid copper... maybe 50 times >> >less if you need to get them gold plated. >> >___ >> >volt-nuts mailing list -- volt-nuts@febo.com To unsubscribe, go to >> >https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts >> >and follow the instructions there. >> > >> >___ >> >volt-nuts mailing list -- volt-nuts@febo.com >> >To unsubscribe, go to >> >https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts >> >and follow the instructions there. >> ___ >> volt-nuts mailing list -- volt-nuts@febo.com >> To unsubscribe, go to https://www.febo.com/cgi-bin/ >> mailman/listinfo/volt-nuts >> and follow the instructions there. >> >___ >volt-nuts mailing list -- volt-nuts@febo.com >To unsubscribe, go to >https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts >and follow the instructions there. ___ volt-nuts mailing list -- volt-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts and follow the instructions there.
Re: [volt-nuts] Banana jack shorting straps
You gentlemen are aware that these things are available from Fluke at a fairly reasonable price? http://nl.farnell.com/fluke/fluke-884x-short/lead-test-4-wire-fluke-884x-short/dp/1274092 Met vriendelijke groet, Rob Klein verstuurd vanaf mijn smartphone Op 9 nov. 2017 14:12, om 14:12, "David C. Partridge" schreef: >Mark > >I'm trying to imagine what you are describing - is this PCBs with 4mm >banana plugs installed or a small PCB with two slots at 3/4" centres to >match the socket spacing? > >If the latter is this intended to cover just two sockets or to short >all four Force and Sense sockets together (if arranged like a 3458A)? > >Thanks >Dave > >-Original Message- >From: volt-nuts [mailto:volt-nuts-boun...@febo.com] On Behalf Of Mark >Sims >Sent: 09 November 2017 02:14 >To: volt-nuts@febo.com >Subject: [volt-nuts] Banana jack shorting straps > >The main use of these would be shorting sense to drive jacks. They >could also be used for input shorts. The advantage over bare copper >would be the ENIG gold finish... bare copper quickly forms oxide layers >and copper oxide has a horrible thermal EMF. Granted, ENIG gold >basically involves waving a bar of gold over the plating tank and >hoping some gold atoms fall off. The board house I use deposits a >thicker layer than most. You don't want to know what "hard gold" >finish would cost. > >Using a PCB house to fab them is probably 20 times less expensive than >having a machine shop do them out of solid copper... maybe 50 times >less if you need to get them gold plated. >___ >volt-nuts mailing list -- volt-nuts@febo.com To unsubscribe, go to >https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts >and follow the instructions there. > >___ >volt-nuts mailing list -- volt-nuts@febo.com >To unsubscribe, go to >https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts >and follow the instructions there. ___ volt-nuts mailing list -- volt-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts and follow the instructions there.
Re: [volt-nuts] FS: Solartron 7081
1200 GBP? Blimey! I sold one of these earlier this year for 1000 euro. Met vriendelijke groet, Rob Klein verstuurd vanaf mijn smartphone Op 13 jul. 2017 19:01, om 19:01, "David C. Partridge" schreef: >I have recently acquired yet another of these, and really don't need >quite >so many of them. > >So I'm selling one of them. It was calibrated about 18 months ago, but >when >I checked it today after 24 hours warm-up it was reading well within >specification on all ranges so I left it as found! The joy of a >well-aged >reference! > >It will come with an input cable and calibration key. > >Preferably for collection from Kenilworth, UK - I will ship it well >packed >if necessary at cost, but will not guarantee the VFD will survive the >journey. > >I'm offering it here first at GBP1200. > >Dave > > > > > > >___ >volt-nuts mailing list -- volt-nuts@febo.com >To unsubscribe, go to >https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts >and follow the instructions there. ___ volt-nuts mailing list -- volt-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts and follow the instructions there.
Re: [volt-nuts] Fluke 332B
Dave, I don't know where you are based, but I happen to have two 5440B's I want to get rid of. Anyone else in Europe who is interested can also react, of course :) Met vriendelijke groet, Rob Klein verstuurd vanaf mijn smartphone Op 9 jul. 2017 17:33, om 17:33, "David C. Partridge" schreef: >Thanks Charles, > >Dave > >-Original Message- >From: volt-nuts [mailto:volt-nuts-boun...@febo.com] On Behalf Of >Charles Steinmetz >Sent: 09 July 2017 13:31 >To: Discussion of precise voltage measurement >Subject: Re: [volt-nuts] Fluke 332B > >David wrote: > >> When running through the calibration of the unit last night, I found >> that it was really quite noisy > > >> So, is it worthwhile to replace the chopper amplifier board and >> replace electrolytic caps or would that just make marginal >> improvements >> >> If it would still be an unstable, noisy brute after I finished that, >then I think I'll put it on eBay ... > >My experience with these extends back to when they were new. They are >definitely noisy even when they are in perfect condition, and this many >years on they tend to be quite unreliable even if they have been >thoroughly gone through. Also, something I haven't seen mentioned much >is that the last decade (LSD) is purely for decoration. The accuracy >of the 332 on its best day is worse than one division of the >second-last decade. > >In my expeience, the original choppers work very well unless they are >broken. I do not expect that a chopper-stabilized op amp would provide >meaningful improvement. > >I advise passing on the 332A/B/D and holding out for a 5440B. You will >not be sorry. > >Best regards, > >Charles > > >___ >volt-nuts mailing list -- volt-nuts@febo.com To unsubscribe, go to >https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts >and follow the instructions there. > >___ >volt-nuts mailing list -- volt-nuts@febo.com >To unsubscribe, go to >https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts >and follow the instructions there. ___ volt-nuts mailing list -- volt-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts and follow the instructions there.
Re: [volt-nuts] PCBs with ceramic substrates
"Tungsten carbide drills? What the bloody hell is tungsten carbide drills?" https://m.youtube.com/watch?v=rQDeU6dHX-c (Sorry, just couldn't resist :) ) Met vriendelijke groet, Rob Klein verstuurd vanaf mijn smartphone Op 16 apr. 2017 15:41, om 15:41, Chuck Harris schreef: >Hi John, > >I am not advocating ceramics in place of FR4, or vice versa. >That was someone else wondering why ceramics weren't used in >metrology... > >As to what you can use that isn't brittle, that is up to your >imagination. Unlike common FR4 materials, ceramics don't do >well with the usual FR4 process of thermally bonding a thin >sheet of copper to each side, masking, etching, and being happy. > >Ceramic PCB's, in my experience, are more of a silk screen >a silver ore gold bearing "glaze" on the surface of the ceramic, >and fire in a kiln process. > >Any ceramic you can get in a thin sheet the thickness you desire, >and in the shape/size you desire is a candidate. > >Some ceramics might not do well with drilling, or other machining >processes, so may have to be formed, drilled, etc. while in the >greenware state. > >I shudder to think what machining ceramic armor plate, as is >used for the breastplate in a "bullet proof vest" might be like. > >There are some ceramics that would eat tungsten carbide drills >for breakfast, so diamond tooling is probably essential. > >-Chuck Harris > >John Devereux wrote: >> >> >> Hi Chuck >> >> But the context is "PCBs with ceramic substrates". Are any of *those* >> tough? They may well be, perhaps you know of some? It does not help >us >> with the subject much if there are ceramics with these amazing >> properties if they are not available as PCBs. >> >> There is also the question of exactly what properties of FR4 are >> limiting for "metrology" use. >> >> John >___ >volt-nuts mailing list -- volt-nuts@febo.com >To unsubscribe, go to >https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts >and follow the instructions there. ___ volt-nuts mailing list -- volt-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts and follow the instructions there.
Re: [volt-nuts] PCBs with ceramic substrates
In general, metrology equipment doesn't get thrown about much ... I know some calibrators have (heated) modules on ceramic substrates, so it's not that it is completely unheard of. Met vriendelijke groet, Rob Klein verstuurd vanaf mijn smartphone Op 7 apr. 2017 20:12, om 20:12, cheater00 cheater00 schreef: >Hi Attilla, >My #1 worry would be fragility. > >On Thu, 6 Apr 2017 06:39 Attila Kinali, wrote: > >> Moin, >> >> I recently wondered, why people around voltage metrology hardly >> talk about ceramic substrates (Al2O3, AlN, ...) for PCBs. >> They have surface resistivity that is as high as PTFE, have >> higher thermal conductivity, lower thermal expansion (AlN is >> even pretty close to Si). So, why then does it hardly ever get >> mentioned? Is it the cost of those? Or is there something I am >> missing? >> >> Attila Kinali >> >> -- >> You know, the very powerful and the very stupid have one thing in >common. >> They don't alters their views to fit the facts, they alter the facts >to >> fit the views, which can be uncomfortable if you happen to be one of >the >> facts that needs altering. -- The Doctor >> ___ >> volt-nuts mailing list -- volt-nuts@febo.com >> To unsubscribe, go to >> https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts >> and follow the instructions there. >> >___ >volt-nuts mailing list -- volt-nuts@febo.com >To unsubscribe, go to >https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts >and follow the instructions there. ___ volt-nuts mailing list -- volt-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts and follow the instructions there.
Re: [volt-nuts] How to keep voltage stable in the sub-100nV range?
"A" voltage? Is that 1mV, 1V, 10V? How fast does it need to be updated? Met vriendelijke groet, Rob Klein verstuurd vanaf mijn smartphone Op 1 nov. 2016 13:14, bij 13:14, Attila Kinali schreef: >Hi, > >I have a "small" side project, which involves keeping a voltage stable >to better than 100nV over the period of several seconds. Ie. a DAC >produces an output and a chain of opamps and low pass filters feeds >it to the consuming device. The absolute value and drift over more >than 10-100s is not that important. > >As I lack a lot of knowledge in this field, I would like to ask >whether someone can point me at literature or give me some terms >to search for that help me to figure out whether this is actually >feasible and how I could achieve that. I know the basic literature >on noise and how to deal with that. What I am interested in are the >real world problems, how big they actually are and how to deal with >them. > > Attila Kinali > >-- >It is upon moral qualities that a society is ultimately founded. All >the prosperity and technological sophistication in the world is of no >use without that foundation. > -- Miss Matheson, The Diamond Age, Neil Stephenson >___ >volt-nuts mailing list -- volt-nuts@febo.com >To unsubscribe, go to >https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts >and follow the instructions there. ___ volt-nuts mailing list -- volt-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts and follow the instructions there.
Re: [volt-nuts] nA advice
50V across 5GOhm is 10nA. Put a standard multimeter's 10MOhm input in series and you have 10mV per nA reading. Anything below 100mV is pass. My 2 eurocents. Rob Klein Op 13-11-2015 om 17:15 schreef Andrea Baldoni: Hello! I would like to measure insulation resistance of some defective load cells. The measurement should be done with no more than 50V and the full scale reading should be >=5Gohm. Accuracy of +-10% is enough (in fact it could suffice just to check if it's >=5Gohm or not). I have not been able to find a ready made instrument that could do this within a reasonable price (100 EUR); the normal insulation resistance testers go much high with the probing voltage (on the purpose, but this also lighten much the requirements on the sensitivity of the meter). It could be as simple as a led indicator "pass/fail", but at this point, why not to build a good frontend for a multimeter, so it could be much more useful? There are many way to do this and also many ready circuits (like the null detector in the mini metrology lab by Conrad Hoffmann) or in the AoE, but instead of making it from scratch, someone knows if there is something already made (or a kit)? Best regards Andrea Baldoni ___ volt-nuts mailing list -- volt-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts and follow the instructions there. ___ volt-nuts mailing list -- volt-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts and follow the instructions there.
Re: [volt-nuts] Fluke 720a self calibration repair
Dave, How many of those pots do you need? I've had the innards of an 88(something) lying around for ages and your welcome to a few, if you're willing to pay shipping from the Netherlands. With only the trimmers in a small box, that should not break the bank. Met vriendelijke groet, Rob Klein. Verstuurd vanaf mijn tablet Dave M schreef: >I tried to find this style trimmer pot with a wirewound resistance element, >but found that all I could find was the Cermet type. It appears that >wirewound pots have all been replaced by Cermet. the wirewound pots had a 1W >power rating, whereas the Cermet pots arte only rated at 3/4W. In the 720A, >the reduced power rating won't be an issue, but in some vintage equipment, >it might be. > >I've also tried, to no avail, to find a source for the metal-cased wirewound >trimmer pots used on the K-V divider in some older Fluke differential >voltmeters, such as the models 883A, 885A and 887A. Does anyone know of a >source for replacements for those pots? I have an 887A on the shelf that >I'd like to get back to original condition if I could find a couple of that >style trimmer pot. They're only 2 ohms, making the search even more >difficult. At this point, my only recourse is to find a defunct donor unit >at reasonable cost, and salvage the parts. Does anyone have a hangar queen >that I could get for shipping charges? I'd be really happy to get mine back >on the road to health. > >Cheers, >Dave M > >Tony wrote: >> Apologies - my mistake - I wasn't paying sufficient attention when >> Google decided that this was a perfect match when searching for >> 300SP-1-502: >> http://uk.farnell.com/webapp/wcs/stores/servlet/Search?st=3400s&catalogId=15001&categoryId=70005471&langId=44&storeId=10151 >> >> But £180.27 each whereas Newark, the US arm of Farnell only want $120 >> or approx £80 for the same part! Are there really that many Brits who >> put up with being ripped-off to these levels? >> >> Tony H >> >> >> On 26/09/2015 01:27, Charles Steinmetz wrote: >>> Charles wrote: >>> >>>>> I had to look it up. The company was Arrow (800 833 3557). The pots >>>>> were manufactured by Bournes with a manufacturer part number of >>>>> 300SP-1-502. Unit cost $7.73 in 2011. I bought 26 so my cost was >>>>> about $200. I wanted a "Manufactured in America" part but can't >>>>> remember if that was too pricey or not. >>> >>> Tony wrote: >>> >>>> They are now $92.55 from Arrow now and Farnell want over $200 each >>>> if you buy 25 or more There don't seem to be any obvious cheap >>>> alternatives for 10 turn 20ppm/C 5W pots. >>> >>> The original pots were Bunker Ramo-Eltra (later, Bunker >>> Ramo-Amphenol) P/N 3800P-502. These were 20-turn, 5k, 10%, 1W, >>> +/-50 ppm/C wirewound parts in the 34b rectangular package. The >>> Bourns 3005P-1-502 matches these specifications (I suspect "300SP" >>> in Charles's message was a typo). I do not know if the pin layout >>> is the same as the 3800P-502. Verical has the lowest price on the >>> 3005P-1-502 that I could find in a quick search, $7.68 each. Others >>> charge from $9 to $14. Tony -- what part number were you quoting specs >>> and prices for? I >>> found nothing searching for "300SP-1-502." >>> >>> Best regards, >>> >>> Charles > > >___ >volt-nuts mailing list -- volt-nuts@febo.com >To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts >and follow the instructions there. ___ volt-nuts mailing list -- volt-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts and follow the instructions there.
Re: [volt-nuts] 3458A resistance calibration
Poul-Henning Kamp schreef op 22-5-2015 om 10:22: In message <555e5d13.4060...@freenet.de>, Frank Stellmach writes: The VHP101 has [...] I'd be surprised if HP didn't have a pretty hostile incoming inspection procedure for this component, so I'd expect the specs of the onces that made it into HP3458 instruments to be somewhat tighter. I've always wondered what a company like HP did with rejects against in-house-specs ? Did they have multiple grades so that the best ended up in 3458, the next best in 3457 and the ones living up to manufactureres spec in 3456 ? Most likely, they have Vishay do the selection for them. As for rejects, there are no VHP101's in either the 3456 or the 3457 :) ___ volt-nuts mailing list -- volt-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts and follow the instructions there.
Re: [volt-nuts] Voltage Reference.
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Re: [volt-nuts] Voltage Reference.
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Re: [volt-nuts] Voltage Reference.
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Re: [volt-nuts] PPM LTD Model 410/411 Voltage Reference
Hi Tony, While I know nothing about this particular device, green precision wire-wound resistors in an English instrument almost certainly are made by Mann Components (later taken over to become Vishay-Mann). They're easily recognized by an "MC" monogram. Regards, Rob. Op 29-8-2013 3:01, Tony Greene schreef: Greetings. I have lurked awhile and have finally found a reason to register and post. I recently purchased a PPM Ltd. (England) model 410/411 voltage reference. This unit is green colored and takes up one rack unit. It appears to be zener based, it has a black box on the PCB that I beleive houses/sheilds the zener. On the rear panel it has bananna jack that is labeled 6.25498V. It has a 1KV and 100V input divider to 1 volt output. It also has a switched output of 10V, 1V, 100mv, 10mv, 8mv, 6mv, 4mv, 2mv, 1mv, and zero volts. The unit uses binding post for the inputs and outputs and it also has a sense and guard binding post. The unit operates on 120 or 240 VAC and had 14 ea "C" nicad cells which were all corroded. The batteries were configured so that 2 cells provided a negative supply, and 12 cells provided a positive supply. The unit uses 0.005 percent wirewound resistors, they are green in color, but I do not reckonize who made the resistors. The unit uses OP07 op amps, using the round "TO" style cans of old opamps. The unit has a calibration sticker showing it was calibrated on 9-87, a transformer inside shows a made date of 1979. I have not been able to locate any information on the net about the unit. I would appreciate any information any person may have on the unit. Thanks, Tony FREE 3D EARTH SCREENSAVER - Watch the Earth right on your desktop! Check it out at http://www.inbox.com/earth ___ volt-nuts mailing list -- volt-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts and follow the instructions there. ___ volt-nuts mailing list -- volt-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts and follow the instructions there.
Re: [volt-nuts] HP 3457A calibration?
Op 20-8-2013 7:39, Dr. David Kirkby schreef: A bit of a silly video IMHO. I can't take anyone seriously who measures the noise on a 6.5 digit multimeter by looking at the digits which change as it is across his standard bench power supply. Personally I would have thought one measured the stability of the bench supply by measuring with the DVM rather than the other way around Not only that, the guy obviously doesn't even know how the thing works, based on his 'explanation' of integration time. Good video for when I can't get to sleep, though ___ volt-nuts mailing list -- volt-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts and follow the instructions there.
Re: [volt-nuts] Sn10Pb90
Op 13-8-2013 20:16, Joseph Gray schreef: I came across a couple of old Fluke differential voltmeters that need some work. I thought it would be best to use low thermal EMF solder on these. I think it would be best *not* to. As far as I know, Fluke never used any low thermal EMF solder on any of its equipment, even the very top-of-the-range stuff. I certainly never seen it mentioned in any service manual for e.g. the 720, 845, 750, 752. Rob. ___ volt-nuts mailing list -- volt-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts and follow the instructions there.
Re: [volt-nuts] Solartron 7071 beeping about twice a second
Op 31-1-2013 10:23, David C. Partridge schreef: 'FOD' OK, I'll bite, what does that one mean? According to Wikipedia: "*Foreign Object Debris* (FOD) is a substance, debris or article alien to a vehicle or system which would potentially cause damage." Rob. ___ volt-nuts mailing list -- volt-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts and follow the instructions there.
Re: [volt-nuts] Solartron 7150plus - Chasing AC gremlins
Phil, However contradictory it may sound, that is actually a good thing. Continuous failures are always easier to chase down than your gremlins. Tracing front to back should bring you to Mount Doom relatively quickly ;-) Kind regards, Rob. Op 13-12-2012 0:10, Philip Pemberton schreef: I suspect whatever was failing has now failed completely. :-/ ___ volt-nuts mailing list -- volt-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts and follow the instructions there.
Re: [volt-nuts] Fwd: Solartron 7150plus - Chasing AC gremlins
As per Philip's original post, _all_ AC ranges drop gradually. This is really not consistent with a faulty EAROM. Rob. Op 7-12-2012 13:19, Wim de Jong schreef: Dave, Thats the question. It depends on the quality of the cells where the AC calibration info is stored. I'm not aware of a checksum function on these EAROM's. If it is the AC part, I've some spare parts if necessary... Just let me know. Kind regards, Wim. Wim de Jong wim.de.jong...@solcon.nl Op 7-12-2012 10:25, David C. Partridge schreef: Wim I don't think that is likely, as Phil clearly says that all the DC ranges are correct, it is just the AC ranges that are a problem. If the EAROMs were bad, you'd lose all the calibration constants. Dave -Original Message- From: volt-nuts-boun...@febo.com [mailto:volt-nuts-boun...@febo.com] On Behalf Of Wim de Jong Sent: 07 December 2012 08:04 To: volt-nuts@febo.com Subject: [volt-nuts] Fwd: Solartron 7150plus - Chasing AC gremlins Phil, I suspect it to be the EAROM(s) IC 105/6 of this meter. Losing its calibration constants. Regards, Wim. Wim de Jong wim.de.jong...@solcon.nl ___ volt-nuts mailing list -- volt-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts and follow the instructions there. ___ volt-nuts mailing list -- volt-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts and follow the instructions there. ___ volt-nuts mailing list -- volt-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts and follow the instructions there.
Re: [volt-nuts] 732 and 752 recently on ebay
And, incidentally, of the two 752's on the 'bay at the moment, the cheapest is $ 850, the other $ 1200. Op 3-11-2012 13:32, m k schreef: Did anyone see the 732a and 752a pair that recently went for 1088 sterling (~1745 dollars us)!! MK ___ volt-nuts mailing list -- volt-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts and follow the instructions there. ___ volt-nuts mailing list -- volt-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts and follow the instructions there.
Re: [volt-nuts] 732 and 752 recently on ebay
Keep in mind that it's extremely rare to find these things on offer in Europe. This may even be the first time I've seen a European 752. Buying them in the US they may cost some 5 or 6 hundred dollars, but shipping to Europe will easily set you back an additional $ 300. So to me this price does not seem excessive. Rob. Op 3-11-2012 13:32, m k schreef: Did anyone see the 732a and 752a pair that recently went for 1088 sterling (~1745 dollars us)!! MK ___ volt-nuts mailing list -- volt-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts and follow the instructions there. ___ volt-nuts mailing list -- volt-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts and follow the instructions there.
[volt-nuts] ESI 2100
Hi all, I have recently acquired a defective ESI 2100 Video Bridge. The problem seems to be in the main board; most likely one (or more) of the decoder ROMs is broken. Unfortunately, the service manual contains everything but the schematics for the main board! Moreover, not having a working device at my disposal, it would be difficult to program a new ROM with the required data. So my questions: - Does anyone have the mainboard schematics for the 2100/2110/2160? - Does anyone have images for the two ROMs and the PLD on the main board? I would be extremely happy to get this rather beautiful machine working again, so any help is much appreciated. Kind regards, Rob Klein. ___ volt-nuts mailing list -- volt-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts and follow the instructions there.
Re: [volt-nuts] HP3457
Fred, I think 700 euros is way too much for a 3457. I also have one, as well as a Keithley 2000 and if I ever should decide to get rid of one of them, it will not be the 2000. I have yet to try the RS-232 connection on the 2000, but I'll get in touch with you when I do. A nice, simple program to get at all the features shouldn't be very hard to write for me. You know how to reach me if you have any further questions. Rob Klein. Op 21-8-2012 20:59, Fred Schneider schreef: I have a solatron 7061 but i am not very impressed with it. Must I go looking for an alternative or is this 7061 when i gave it a good checkup / overhaul a good meter ? I am offered a 3457 for 700 euro and the owner, will calibrate it (he has several calibrtors, standards and a couple of 3458 meters. My intuition tells me to trusts him ( and that had never let me down before)) But he also told it is only 7,5 digit over hpib, and has 6,5 digit display. My Keithly 2000 is 6,5 digits and over RS232 i get two digits extra. I once tried that, but that took me a lot of time to get it more ore less working, I am not so into computers and afraid I do not get it to work. Is it really better as my ( one year old 2000 ?) and better as my Solartron can be ? I am afraid a 3458 is outside my budget. Fred Fred PA4TIM ___ volt-nuts mailing list -- volt-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts and follow the instructions there. ___ volt-nuts mailing list -- volt-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts and follow the instructions there.
Re: [volt-nuts] Thermistor value for 732A Reference 10V Standard
Bill, I had to read it twice myself, but that was Mitch' point. When you want to check the performance of the oven, you want to measure something that has a decent bit of variation over temperature. Rob. Op 29-6-2012 13:33, WB6BNQ schreef: Mitch, Quite the contrary. The 10 volt output is the master output and therefore the most stable. The others are derived from dividers and thus add additional error terms due to the tempco of the divider string and any possible loading presented to those outputs. BillWB6BNQ Mitch Van Ochten wrote: I think monitoring the 1V or 1.1V is a better test over temperature than monitoring the 10V. It's quite stable even without the heater. ___ volt-nuts mailing list -- volt-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts and follow the instructions there.
Re: [volt-nuts] Thermistor value for 732A Reference 10V Standard
Op 29-6-2012 6:34, Tom Leedy schreef: Has anyone actually measured the internal temperature of the oven (in degrees C)? Since the operating temperature of the 732A is spec'd at 40 C, I suspect that it is about 45-50 C, or so. According to the manual it's 48 ± 2°C And I also suspect that temperature stability of the oven is more important than absolute accuracy. You'd be correct :-) I didn't expect the large outpouring of knowledge! *Nobody* expects the large outpouring of knowledge! (with apologies to M. Python) Rob. ___ volt-nuts mailing list -- volt-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts and follow the instructions there.
Re: [volt-nuts] Thermistor value for 732A Reference 10V Standard
Hi Tom, Definitely not good! The thermistor is supposed to be an NTC, so seeing the value rise from cold means there's something very wrong indeed. If you want to replace it, this might be a good alterative: http://www.digikey.nl/product-detail/en/192-103LET-A01/480-3158-ND/1886044 Kind regards, Rob Klein. Op 29-6-2012 1:04, lee...@aol.com schreef: Hi! Can anyone give me a rough value of the thermistor resistance that is brought out to the front panel of a Fluke 732A DC Reference Standard (lower left-hand side)? The thermistor is for the user to monitor the temperature of the oven that contains the voltage reference. I see a resistance that starts out at 6600 Ohms (unit was nearly cold) and climbs and levels out at about 8400 Ohms after a day, or so. Is this reasonable? The thermistor is given in the parts list as RT2, a Fenwal JA41J1 (no longer made) and on the schematic as a 10K @ 25C unit. So this doesn't make sense. Does anyone have any experience with this? Or is just simpler to replace the thermistor with a 100 Ohm RTD and be done with it? Or would this drive the calibration labs nuts? Any references or advice would be appreciated. Tom Leedy Clarksburg, MD ___ volt-nuts mailing list -- volt-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts and follow the instructions there. ___ volt-nuts mailing list -- volt-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts and follow the instructions there.
