[volt-nuts] 732A and Prologix received
acbern at gmx.de
acbern at gmx.de
Wed Aug 27 15:34:55 EDT 2014
hi randy,
the specified drift of the 3458a over your 38.1 to 40.3 (about 1k) is 1ppm +/- allone in the 10v range. thats 10uv. in other ranges its worse.
unless your 732a is very bad (very unlikely), you measure mostly the 3458a temp. drift. 1000nplc and 100 readings average do not make sense in that context. if your goal is to be at 0.01ppm additional gain error by using the nplc1000, you need to be sure your temp related drift is even below that. 0.01ppm of temp drift equates 20mk temp stability! you see that all this does not make much sense.
adrian
> Gesendet: Mittwoch, 27. August 2014 um 15:37 Uhr
> Von: "Randy Evans" <randyevans2688 at gmail.com>
> An: "Discussion of precise voltage measurement" <volt-nuts at febo.com>
> Betreff: Re: [volt-nuts] 732A and Prologix received
>
> The HP3458A and the Fluke 732A are on continuously and I do an ACAL at
> least every few hours, or when the room temperature changes by more than 1
> degree C. The total range of measurements is 10uV so the drift is +/-5uV,
> or 0.5 ppm. The room temperature is not particularly stable and varies
> over a 3C range. The internal temp of the 3458 varies from 38.1 to 40.3
> degrees C over the set of measurements. The 732A thermistor resistance
> measures from 3.6677 Kohms to 3.6686 Kohms. I am using copper wires
> between the 3458A and the 752A to minimize thermals. At the moment I have
> no way to tell which unit is drifting the most.
>
> Randy
>
>
> On Wed, Aug 27, 2014 at 6:41 AM, <acbern at gmx.de> wrote:
>
> > 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" <randyevans2688 at gmail.com>
> > > An: "Discussion of precise voltage measurement" <volt-nuts at 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 <randyevans2688 at 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, <acbern at 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" <randyevans2688 at gmail.com>
> > > >> > An: "Discussion of precise voltage measurement" <volt-nuts at 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 <
> > randyevans2688 at 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 <wpgold3637 at 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" <randyevans2688 at gmail.com>
> > > >> > >> To: "Discussion of precise voltage measurement" <
> > volt-nuts at 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 <
> > wpgold3637 at 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" <randyevans2688 at gmail.com>
> > > >> > >> > > To: "Discussion of precise voltage measurement" <
> > > >> volt-nuts at 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 <
> > > >> tmicallef at 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 <
> > > >> > >> > > randyevans2688 at 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
> > > >> > >> > > > > > _______________________________________________
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