Randy, Sorry for the two graphs being at different scales so just be sure to readjust your reference. I like to think in PPM terms so the first graph is +/- 5 PPM for the whole gray plot area while the second is +/- 1 PPM. The most extreme outliers on the first graph is +0.3 to -0.5 PPM so that would be <10.0 uV. The winter graph is +0.1 to -0.9 PPM and would be 10.0 uV. All referenced around 10.0 V.
Don -----Original Message----- From: volt-nuts [mailto:volt-nuts-boun...@febo.com] On Behalf Of Randy Evans Sent: Wednesday, August 27, 2014 10:50 AM To: Discussion of precise voltage measurement Subject: Re: [volt-nuts] 732A and Prologix received Don, If I am reading your charts correctly, it looks like your system is cycling over an 7 uV range over several days in summer, similar to what I am seeing. I don't have air conditioning (Northern California) so I do get some pretty good temperature variations from day to night, but less inside the house. I need to figure out how to share files in Dropbox since I don't have my own web site. Good idea. thanks, Randy On Wed, Aug 27, 2014 at 7:40 AM, Don@True-Cal <truecalservi...@gmail.com> wrote: > I have included a link to an ~30-hour measurement run that I > consistently do that should give you some idea of expected measurement drift > over time. > Virtually all of the measurement drift is due to the 3458A internal > temperature differences around the 7V reference caused by ambient > temperature change. The drift associated with the 732A is probably > about 2-magnitudes less at this ambient temp drift. In my situation, > the inferred ambient temperature is cycling with the home > air-conditioning. Note the initial calibration temperatures as well as > the ACal temperatures and where the 3458A is measuring exactly 10V > relative to those temperatures. My primary 732A has been powered > without loss for 4 years and >5 years before that. The 3458A is > Agilent (Loveland) Cal'ed yearly and is powered 24-7-365 except for > the occasional mains power loss. The graphical measurements is using a > homegrown Agilent VEE program. It is very helpful if not essential to get an > HPIB interface setup so you can do long term graphical analysis. > > The other link was done in winter time when the lab a few degrees cooler. > > > https://www.dropbox.com/s/8je482i3r0belqn/732A%20gold%20%26%203458A%20 > gold%2032-hour%20Ref%20Test%208-21-2014.pdf?dl=0 > > > https://www.dropbox.com/s/xv3l9py7tx6hyh7/HP%20732A%20gold%20%26%20345 > 8A%20gold%207-day%2010.0v%20Ref%20Test.pdf?dl=0 > > I hope these Dropbox links work internationally - I'm new to using > this sharing method. > > Don Johnson > > -----Original Message----- > From: volt-nuts [mailto:volt-nuts-boun...@febo.com] On Behalf Of > acb...@gmx.de > Sent: Wednesday, August 27, 2014 8:42 AM > To: Discussion of precise voltage measurement > Subject: Re: [volt-nuts] 732A and Prologix received > > well, what you do is to measure the stability of the 3458a. 1ppm drift > though sounds much as overall short term average variation if your > temperature is stable and your 3458a is always on. probably the temp > is not stable, and that is what you see, amongst potentially some > other smaller drifts like emf. before every cycle you should do an > acal dcv, if you still see 10uv +/- drifts that then seems too much. > (one thing I need to add is that one of my 3458a, not yet modified to > have lower reference temperature, has drifts when switched on and off. > that is not so much the case with modified reference. but my > assumption re the above is that your meter is always on, as I said) > 732a references et al do have small short term drifts, you can > determine them with a josephson element (these guys told me), but the 732a is > certainly very stable short term compared to a 3458a. > my 732a e.g. has a drift of 0.2ppm per year. > > > > Gesendet: Mittwoch, 27. August 2014 um 14:36 Uhr > > Von: "Randy Evans" <randyevans2...@gmail.com> > > An: "Discussion of precise voltage measurement" <volt-nuts@febo.com> > > Betreff: Re: [volt-nuts] 732A and Prologix received > > > > I forgot to mention that I reduced the number of measurements to 100 > > per set since I wasn't seeing much difference in the variance > > between 100 and > > 1000 measurements and the 1000 measurement per set takes too long. > > > > Randy > > > > > > On Wed, Aug 27, 2014 at 5:13 AM, Randy Evans > > <randyevans2...@gmail.com> > > wrote: > > > > > I am doing multiple 100 measurements simply to characterize the > stability > > > of the 3458A and 732A units I just bought. After about 10 > > > measurement > sets > > > over 2 days I am seeing a variance of about .5 uV for the 10V > > > output, > or > > > 0.05 ppm. However, the mean varies over a range of 10 uV, or 1 ppm. > Does > > > that sound reasonable/ > > > > > > Randy > > > > > > > > > On Tue, Aug 26, 2014 at 5:41 PM, <acb...@gmx.de> wrote: > > > > > >> hi randy, > > >> > > >> just for curiosity, why doing 100 measurements at nplc 1000. is > > >> this > to > > >> sample a changing value? > > >> when i am doing 10 measurements from a stable signal at nplc 100 > > >> (only there many subsequent measuremnts with statistics make > > >> sense) I am > already > > >> getting a stanard deviation below 0.1ppm. > > >> in a 30 minute test cycle, i would also be concerned about drifts > (acal) > > >> unless the amb. temperature is really very stable (half a degree > already > > >> adds about 0.25ppm at 10v) > > >> > > >> thanks > > >> > > >> > > >> > > >> > > >> > Gesendet: Dienstag, 26. August 2014 um 04:23 Uhr > > >> > Von: "Randy Evans" <randyevans2...@gmail.com> > > >> > An: "Discussion of precise voltage measurement" > > >> > <volt-nuts@febo.com > > > > >> > Betreff: Re: [volt-nuts] 732A and Prologix received > > >> > > > >> > Is there any way to tell when the function key routine is > complete? In > > >> the > > >> > case of taking multiple readings using the DEFKEY and MATH > function, I > > >> > don't see any indication when the routine is complete. In one > > >> particular > > >> > case, I am taking a 100 readings with NLPC set for 1000 so its > > >> > a > long > > >> while > > >> > before it's complete, but i have to guess when it's done. > > >> > > > >> > Thanks, > > >> > > > >> > Randy > > >> > > > >> > > > >> > On Sun, Aug 24, 2014 at 6:04 PM, Randy Evans < > randyevans2...@gmail.com> > > >> > wrote: > > >> > > > >> > > Bill, > > >> > > > > >> > > I am trying to figure out the MATH function without much > success. I > > >> input > > >> > > the sequence you said (I looked up the instructions to > > >> > > understand > > >> what you > > >> > > did - seems logical), BLUE DEFKEY BLUE F1 MATH 14;NRDGS > > >> > > 40;TRIG > > >> 4;TRIG; and > > >> > > it shows up on the display when I input BLUE F1. I hit ENTER > > >> > > and > it > > >> takes > > >> > > the 40 measurements and the MATH symbol shows on the display > during > > >> the > > >> > > measurements. After the SMPL symbol no longer blinks I hit > > >> > > MATH 2 > > >> and I > > >> > > get a MATH ERR symbol on the display. I tried it a couple of > times > > >> and the > > >> > > same result so I am doing something wrong. Is there a better > source > > >> for > > >> > > explaining how to do front panel masurements than the User > > >> > > Guide, > > >> which > > >> > > seems oriented at programming automatic rather than manual > > >> measurements. > > >> > > > > >> > > Randy > > >> > > > > >> > > > > >> > > > > >> > > On Sun, Aug 24, 2014 at 4:46 PM, Bill Gold > > >> > > <wpgold3...@att.net> > > >> wrote: > > >> > > > > >> > >> Randy: > > >> > >> > > >> > >> The MATH function is accessible from the keypad. I > > >> > >> don't > have > > >> an IEEE > > >> > >> interface right now that works. You can also program the > > >> > >> numeric > > >> keypad > > >> > >> keys to have preprogrammed functions. DEFKEY > > >> > >> > > >> > >> I have made my own "low thermal" measurement leads from > Pomona > > >> #4892 > > >> > >> banana plugs and Belden #9272 wire. Why 9272, because it > > >> > >> was > handy > > >> at the > > >> > >> time. It is tin plated copper, shielded twisted pair 20 ga. > > >> > >> I > have > > >> plans > > >> > >> to do custom cables with 16 ga. bare copper wire that I will > twist > > >> and > > >> > >> then > > >> > >> put a braided shield over it. I simply cannot find what I > > >> > >> want > so I > > >> will > > >> > >> build my own cable. I have done something like this before > > >> > >> and > it > > >> worked > > >> > >> fine. When I get a "round toit". > > >> > >> > > >> > >> I have 6 ea. Pomona 1756-48 spade lug low thermal leads > > >> > >> that > I > > >> have > > >> > >> used > > >> > >> in the past to verify my homemade "low thermal" leads as > described > > >> above. > > >> > >> Frankly I cannot see any difference between using the 1756 > > >> > >> cables > > >> and my > > >> > >> homemade cables once I give them a few minutes for the > > >> > >> thermals > to go > > >> > >> away. > > >> > >> As far as I can tell and measure the differences, if any, > > >> > >> are > below > > >> 0.1 > > >> > >> ppm > > >> > >> at 10 volts. > > >> > >> > > >> > >> Since the 10 volt, 1.0 volt and 1.018 volt outputs on > > >> > >> the > 732A > > >> are all > > >> > >> adjustable you may be seeing a misadjusted 1 volt from the > 732A. As > > >> far > > >> > >> as > > >> > >> the instability of the readings it is hard to determine > > >> > >> which is > > >> causing > > >> > >> the > > >> > >> problem. I have programed (DEFKEY) a numeric keypad key #1 > > >> > >> with > the > > >> > >> following code. "MATH 14;NRDGS 40;TRIG 4;TRIG ;" So what this > > >> does is > > >> > >> set > > >> > >> the MATH to "Statistics" (store high reading/low reading/ > > >> > >> and > mean > > >> of the > > >> > >> readings) in the registers, the number of readings to "40", > > >> > >> the > > >> trigger to > > >> > >> "hold" (which keeps the meter from triggering until I press > "ENTER" > > >> and > > >> > >> then > > >> > >> trigger the sequence of 40 readings when I push the "ENTER" > button. > > >> You > > >> > >> can > > >> > >> do all of this manually from the keypads but since I use > > >> > >> this > > >> sequence a > > >> > >> lot > > >> > >> I have preprogrammed it. This is after I set digits to "8" > > >> > >> and > PLC > > >> to > > >> > >> 100. > > >> > >> Once those 40 readings are finished then you can access the > various > > >> MATH > > >> > >> statistic registers, using the menu, by entering "MATH" and > > >> > >> then > a 2 > > >> for > > >> > >> low, a 4 for mean, and 13 for high. Of course you could do > > >> > >> all > of > > >> this > > >> > >> through the IEEE also. The 3458A has a very rich set of > measurement > > >> > >> commands. I am still learning all of them. It depends upon > what I > > >> am > > >> > >> trying to accomplish. > > >> > >> > > >> > >> Since the 1.018 and 1.0 volt outputs are passive and > > >> > >> derived > from > > >> > >> resistive dividers from the 10 volt, I don't see how they > > >> > >> could > > >> contribute > > >> > >> to the varying readings you are measuring. I think I would > > >> > >> put a > > >> short on > > >> > >> the input of the 3458A and manually set the range to 1 volt > > >> > >> and > then > > >> > >> observe > > >> > >> the variations that way without the 732A involved. When I > > >> > >> do > this I > > >> see a > > >> > >> variation from low reading to high reading of 0.125 uVolts > > >> > >> and > then > > >> > >> another > > >> > >> 40 I get 0.155 uVolts. This is without the GUARD connected > > >> > >> to > the > > >> low > > >> > >> side > > >> > >> of the measurment terminals, GUARD connected doesn't seem to > affect > > >> the > > >> > >> readings. So that is the base noise of the 3458A without > > >> > >> the > 732A, > > >> > >> somewhere below .2uVolts. When hooked up to the 732A 1.0 > > >> > >> volt > > >> output I > > >> > >> got > > >> > >> a variation of 0.159 uVolts using the same 40 reading method > above. > > >> I > > >> > >> would > > >> > >> use this to determine where your problem might exist. Just > having > > >> the > > >> > >> meter > > >> > >> input shorted will point you in the right direction. Meter, > cables > > >> or > > >> > >> 732A. > > >> > >> > > >> > >> Sorry for the long dissertation. Friends get mad at me > > >> > >> for > > >> being so > > >> > >> detailed sometimes. > > >> > >> > > >> > >> Bill > > >> > >> > > >> > >> ----- Original Message ----- > > >> > >> From: "Randy Evans" <randyevans2...@gmail.com> > > >> > >> To: "Discussion of precise voltage measurement" < > volt-nuts@febo.com> > > >> > >> Sent: Sunday, August 24, 2014 7:22 AM > > >> > >> Subject: Re: [volt-nuts] 732A and Prologix received > > >> > >> > > >> > >> > > >> > >> > Bill, > > >> > >> > > > >> > >> > I have convinced myself that the problem I an seeing is > > >> > >> > due to > > >> thermals. > > >> > >> > If I move the cables (with gold-plated banana plugs) > > >> > >> > using a > small > > >> > >> towel > > >> > >> > rather than letting my hand touch the plugs, it is much > > >> > >> > more > > >> stable. > > >> > >> If I > > >> > >> > then hold the banana plug with my hand after the reading > > >> > >> > has > > >> stabilized, > > >> > >> > the reading drifts rapidly upward. I am trying to check > > >> > >> > the > > >> stability > > >> > >> of > > >> > >> > the reading but I haven't figured out the MATH function > > >> > >> > yet. I > > >> assume > > >> > >> this > > >> > >> > is a programmed function using GPIB only? > > >> > >> > > > >> > >> > The stability I am seeing by manually recording readings > > >> > >> > (using > > >> NLPC of > > >> > >> 100 > > >> > >> > and 1000) is much greater than what you are measuring on > > >> > >> > your > > >> system. > > >> > >> Not > > >> > >> > sure how to ascertain if it's the 3458A or the 732. The > > >> > >> > value > of > > >> the > > >> > >> > readings are very different between the two - the 3458 > > >> > >> > reads > about > > >> 50 uV > > >> > >> > high on the 10 V output and about 12 uV low on the 1V output. > > >> Rather > > >> > >> large > > >> > >> > differences (this is after an ACAL). I need to find some > better > > >> cables > > >> > >> to > > >> > >> > make sure the errors are not due to thermals again. > > >> > >> > > > >> > >> > Randy > > >> > >> > > > >> > >> > > > >> > >> > On Sat, Aug 23, 2014 at 10:21 AM, Bill Gold < > wpgold3...@att.net> > > >> wrote: > > >> > >> > > > >> > >> > > Randy: > > >> > >> > > > > >> > >> > > I get 6 volt 4 amp/hr (or 4.5 amp/hr) batteries and > > >> > >> > > they > > >> will fit > > >> > >> > > perfect. Power Sonic PS-640, Genesis NP4-6, Panasonic > > >> LC-R064R5C and > > >> > >> > > others > > >> > >> > > that are in this size and package. Order from one of > > >> > >> > > the > usual > > >> > >> electronics > > >> > >> > > distributors like Allied, Mouser, Digikey. This is a > > >> > >> > > very > common > > >> > >> battery > > >> > >> > > as > > >> > >> > > it is used in a lot of "EXIT" signs so they are lighted > > >> > >> > > when > the > > >> power > > >> > >> goes > > >> > >> > > out. I don't see how the 12V 7AH will fit as they are > > >> > >> > > too > > >> large. I > > >> > >> guess > > >> > >> > > you could use a 12V 5AH (PS1250) as it is the same size > > >> > >> > > as 2 > x 6 > > >> volt > > >> > >> 4 > > >> > >> AH > > >> > >> > > but the terminals are in the wrong place so you will > > >> > >> > > have to > > >> "nibble" > > >> > >> out > > >> > >> > > the aluminum plate that holds them in the 732A battery pack. > > >> You have > > >> > >> to > > >> > >> > > be > > >> > >> > > careful if you use the 12v 5AH as you will have 4 extra > battery > > >> > >> connection > > >> > >> > > leads to deal with and connect correctly. I would stick > > >> > >> > > with > > >> the 6V > > >> > >> 4AH. > > >> > >> > > New batteries will last around 12 to 14 hours before the > "CAL" > > >> light > > >> > >> goes > > >> > >> > > out when AC power is not applied. So shipping to Cal > > >> > >> > > Lab > can be > > >> a > > >> > >> problem > > >> > >> > > if it is a distance away, or you have to use a shipper > > >> > >> > > like > UPS > > >> or > > >> > >> FEDEX > > >> > >> > > and > > >> > >> > > you ship the night before and then use their "Morning > delivery" > > >> and > > >> > >> the > > >> > >> Cal > > >> > >> > > Lab is expecting your 732A. Same on the way back to > > >> > >> > > you. Of > > >> course > > >> > >> you > > >> > >> > > could always strap another battery on the 732A and hook > > >> > >> > > it > up to > > >> the > > >> > >> "ext > > >> > >> > > power" plug to last longer. I have seen it done. The > > >> > >> > > issue > is > > >> to get > > >> > >> the > > >> > >> > > Cal Lab to charge the extra battery before they ship the > > >> > >> > > 732A > > >> back to > > >> > >> you. > > >> > >> > > > > >> > >> > > When you remove and work on the battery pack always > > >> > >> > > have > the > > >> AC > > >> > >> power > > >> > >> > > plugged in. The "CAL" led will stay on because the 18.6 > > >> > >> > > v > > >> regulated > > >> > >> supply > > >> > >> > > is working. > > >> > >> > > > > >> > >> > > The "CAL" light is to indicate that power has not > > >> > >> > > been > lost > > >> to the > > >> > >> > > Reference Amp or other associated circuits. When the > > >> > >> > > raw > supply > > >> > >> (battery) > > >> > >> > > voltage drops below about 21 volts the "CAL" light will > > >> > >> > > go > out. > > >> Below > > >> > >> that > > >> > >> > > voltage the heater circuits will not work correctly and > > >> > >> > > the > 18.6 > > >> volt > > >> > >> > > regulated supply will not regulate. The requirement is > > >> > >> > > that > the > > >> > >> Reference > > >> > >> > > Amp be kept "alive" at all times to maintain the output > voltage > > >> that > > >> > >> was > > >> > >> > > measured at the time of the most recent Calibration or > > >> Certification. > > >> > >> When > > >> > >> > > the semiconductor junctions are unbiased and cool off > > >> > >> > > when > power > > >> is > > >> > >> lost, > > >> > >> > > and then power is restored the result will be a > > >> > >> > > different 10 > > >> volts > > >> > >> than > > >> > >> > > before the power failure. My experience is that after > > >> > >> > > all > of the > > >> > >> years > > >> > >> > > that > > >> > >> > > these units have been powered up, this won't happen and > > >> > >> > > when > > >> power is > > >> > >> lost > > >> > >> > > and then restored, even months later, the 732A will come > back to > > >> > >> almost > > >> > >> > > exactly the same 10 volts as when they lost power, > > >> > >> > > usually > with > > >> in 0.2 > > >> > >> PPM > > >> > >> > > after 24 hours of "warm up". > > >> > >> > > > > >> > >> > > What type of hookup leads are you using when > > >> > >> > > measuring > the 1 > > >> volt > > >> > >> > > output? What is the PLC set to? I always use 100 PLC > > >> > >> > > to > measure > > >> > >> this. > > >> > >> If > > >> > >> > > you don't have "low thermal" connection leads you can > experience > > >> uV > > >> > >> changes > > >> > >> > > for a minute or more after plugging in the leads due to > > >> > >> > > the > > >> "thermals" > > >> > >> > > generated because of the difference in temperature > > >> > >> > > between > the > > >> banana > > >> > >> jacks > > >> > >> > > on the 732A and the banana plugs of the leads. I have > > >> > >> > > found > > >> that even > > >> > >> just > > >> > >> > > plugging in the lead will generate a thermal difference > because > > >> of > > >> > >> > > difference of temps and some heating due to the physical > > >> > >> > > act > of > > >> just > > >> > >> > > inserting the plug because of friction between the jack > > >> > >> > > and > plug > > >> (my > > >> > >> theory > > >> > >> > > at any rate). You have to allow at least a minute or > > >> > >> > > more > before > > >> > >> being > > >> > >> > > able > > >> > >> > > to make a measurement after plugging in the leads. I > > >> > >> > > just > > >> measured > > >> > >> the > > >> > >> > > variation of the 1 volt output of my 732A and using my > > >> > >> > > 3458A > and > > >> I > > >> > >> got a > > >> > >> > > total difference of 0.159 uV over 40 measurements using > > >> > >> > > 100 > PLC > > >> on > > >> > >> the > > >> > >> 1 > > >> > >> > > volt range of the 3458A. Using the MATH function and > > >> > >> > > all of > the > > >> data > > >> > >> you > > >> > >> > > can collect. That was after waiting for several minutes > after > > >> > >> plugging > > >> > >> in > > >> > >> > > the leads. > > >> > >> > > > > >> > >> > > I hope all of this helps. > > >> > >> > > > > >> > >> > > Bill > > >> > >> > > > > >> > >> > > > > >> > >> > > > > >> > >> > > ----- Original Message ----- > > >> > >> > > From: "Randy Evans" <randyevans2...@gmail.com> > > >> > >> > > To: "Discussion of precise voltage measurement" < > > >> volt-nuts@febo.com> > > >> > >> > > Sent: Friday, August 22, 2014 9:03 PM > > >> > >> > > Subject: Re: [volt-nuts] 732A and Prologix received > > >> > >> > > > > >> > >> > > > > >> > >> > > > Todd, > > >> > >> > > > > > >> > >> > > > Thanks for the info. I have several Panasonic 12V 7 > > >> > >> > > > AH > > >> batteries > > >> > >> that > > >> > >> I > > >> > >> > > > keep topped off and they have very low current draw > > >> > >> > > > (~2 to > 3 > > >> mA at > > >> > >> 13.5 > > >> > >> > > > VDC) when charged and at their float voltage, so I am > pretty > > >> sure > > >> > >> they > > >> > >> > > are > > >> > >> > > > in good condition. I will look at getting those in > > >> > >> > > > the > units > > >> after > > >> > >> I > > >> > >> > > > ascertain the condition of the 732. > > >> > >> > > > > > >> > >> > > > So now I have a what appears to be a functioning 3458A > > >> > >> > > > and > a > > >> 732A > > >> > >> but > > >> > >> > > they > > >> > >> > > > slightly disagree. I am like the man with two watches > > >> > >> > > > that > > >> disagree > > >> > >> on > > >> > >> > > the > > >> > >> > > > time - which is correct? For the moment, i am only > concerned > > >> with > > >> > >> > > > stability. The need for absolute accuracy will come later. > > >> > >> > > > > > >> > >> > > > Randy > > >> > >> > > > > > >> > >> > > > > > >> > >> > > > On Fri, Aug 22, 2014 at 8:06 PM, Todd Micallef < > > >> tmical...@gmail.com > > >> > >> > > > >> > >> > > wrote: > > >> > >> > > > > > >> > >> > > > > Randy, > > >> > >> > > > > > > >> > >> > > > > You have two possible choices. It can be configured > > >> > >> > > > > with > 4 x > > >> 6v > > >> > >> 4Ah > > >> > >> > > > > batteries or 2 x 12v 7Ah batteries. Hopefully the > previous > > >> owner > > >> > >> has > > >> > >> > > > > modified the battery pack already. A couple of mine > needed a > > >> > >> nibbler > > >> > >> > > tool > > >> > >> > > > > to remove enough of the aluminum cover that fits > > >> > >> > > > > over the > > >> tops of > > >> > >> the > > >> > >> > > > > batteries. The original cover will short out to the > battery > > >> tabs > > >> > >> > > regardless > > >> > >> > > > > of the battery configuration if this is not done. > > >> > >> > > > > > > >> > >> > > > > You can find larger capacity batteries that will > > >> > >> > > > > give you > > >> slightly > > >> > >> more > > >> > >> > > > > battery life. I lost a couple sets of mail-order > batteries > > >> after a > > >> > >> few > > >> > >> > > > > extended outages. I would recommend going with > > >> > >> > > > > locally > bought > > >> > >> batteries > > >> > >> > > > > instead of the cheaper mail order. My local > > >> > >> > > > > Batteries > Plus > > >> will > > >> > >> > > typically > > >> > >> > > > > have some warranty if I remember correctly. Moving > forward I > > >> will > > >> > >> only > > >> > >> > > use > > >> > >> > > > > 2 12v batteries and pre-charge them on a battery > > >> > >> > > > > charger > to > > >> > >> equalize > > >> > >> > > them > > >> > >> > > > > before putting them in the 732A. I think the cheap > batteries > > >> did > > >> > >> not > > >> > >> > > > > discharge equally, and would not recover when power > > >> > >> > > > > was > > >> applied. > > >> > >> > > > > > > >> > >> > > > > Inspect the back plane for damaged traces and look > > >> > >> > > > > at the > > >> > >> capacitors. I > > >> > >> > > had > > >> > >> > > > > a few that looked questionable. So far, I have > > >> > >> > > > > replaced > all > > >> the > > >> > >> big > > >> > >> > > caps > > >> > >> > > on > > >> > >> > > > > the pre-regulator and regulator boards. My feeling > > >> > >> > > > > is > that > > >> once > > >> > >> these > > >> > >> > > go > > >> > >> > > > > online, they should run as long as possible between > repairs. > > >> > >> > > > > > > >> > >> > > > > The battery charger circuit may need adjusting. I > > >> > >> > > > > tweaked > > >> mine and > > >> > >> it > > >> > >> > > > > seemed to work fine. > > >> > >> > > > > > > >> > >> > > > > Todd > > >> > >> > > > > > > >> > >> > > > > > > >> > >> > > > > On Fri, Aug 22, 2014 at 10:42 PM, Randy Evans < > > >> > >> > > randyevans2...@gmail.com> > > >> > >> > > > > wrote: > > >> > >> > > > > > > >> > >> > > > > > I received my Fluke 732A today. Just powered it > > >> > >> > > > > > up > but it > > >> needs > > >> > >> new > > >> > >> > > > > > batteries. Any suggestions for sources (I haven't > opened > > >> up the > > >> > >> unit > > >> > >> > > > > yet - > > >> > >> > > > > > I want to make sure it works before doing that). > > >> > >> > > > > > Also > > >> received > > >> > >> the > > >> > >> > > > > > ProLogix USB-GPIB adapter. I plan on using Mark Sims' > CAL > > >> ran > > >> > >> data > > >> > >> > > > > dumper > > >> > >> > > > > > program to get the CAL data from my 3458A. Should > > >> > >> > > > > > be a > > >> busy > > >> > >> weekend. > > >> > >> > > > > > > > >> > >> > > > > > Randy > > >> > >> > > > > > _______________________________________________ > > >> > >> > > > > > 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-n > > >> > >> > > > > uts 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. > > >> > >> > > >> > > > > >> > > > > >> > _______________________________________________ > > >> > 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. > _______________________________________________ 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.
