Re: [volt-nuts] Prema 6048 Cal switch confusion
How about copying the contents of the old nvram to the new one? - Original Message - From: "David C. Partridge" To: "'Discussion of precise voltage measurement'" Sent: Thursday, November 02, 2017 2:58 PM Subject: Re: [volt-nuts] Prema 6048 Cal switch confusion Update - when I tried this I was using a brand new DS1220AD-100IND (blank) to replace the DS1220Y. Reinstalling the DS1220Y and it worked as expected! Processor must detect cal mode by writing to NVRAM - if succeeds, then in Cal mode??? Maybe Is there some obscure incompatability between the DS1220AD and the DS1220Y??? Dave -Original Message- From: volt-nuts [mailto:volt-nuts-boun...@febo.com] On Behalf Of David C. Partridge Sent: 02 November 2017 18:23 To: 'Discussion of precise voltage measurement' Subject: [volt-nuts] Prema 6048 Cal switch confusion I've got a Perma 6048 that I've trying to put into Cal mode. It just won't! The switch on the rear panel works OK, AFAICT when in the Cal position it connects ~WE on the DS1220 (pin 21) and ~W on the $864 SRAM (pin 27) to a 4K7 pullup to +5V and to the output of an LS00 which should be strobing the Write lines low as needed. I can't see any way in which the processor can be informed of the switch setting! In measure mode it just connects ~WE on the DS1220 to a 10k pullup to +5V. The schematic is on page 120 (Figure 11.4) of the user manual and also page 9-7 of the service manual. Clearly I'm missing something - as a friend reports that his does go into cal mode. Confused ... Thanks 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. ___ 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
Ceramic plates are even used in armor to stop armor piercing projectiles. Lots of applications. - Original Message - From: "Chuck Harris" To: "Discussion of precise voltage measurement" Sent: Wednesday, April 12, 2017 5:04 PM Subject: Re: [volt-nuts] PCBs with ceramic substrates Simple, ceramic is a generic term, like car. And, ceramic substrates are available in all manner of different thicknesses, densities, and materials. Like every other engineering material, you decide what characteristics are important to you, and you pick the appropriate material that meets those characteristics. If you work outside of the envelope of that material's capabilities, the results will be disappointing. You were opining that ceramic was too brittle, and breakable and shouldn't be used for metrology work, I disagreed, and attempted to enlighten you with tales of some ceramics that you would be hard pressed to break, even with repeated blows from a hammer. I could tell you of transparent ceramics that are amazingly hard, and strong. I could go further and tell of other ceramics where you can crumble brick sized blocks with light finger pressure. And I could tell you of still other ceramics that you can heat white hot with a torch, and then in a fraction of a second, press the glowing section against your arm without it even feeling warm. Which could lead some to say: ceramics are cool! But as they say, you can lead a horse to water, but you cannot make him drink. -Chuck Harris cheater00 cheater00 wrote: What can account for this difference between your and my experience and what Chuck said? ___ 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] Basic question concerning voltage references
I believe you can get 7-1/2 digits out of the 3457A via the HPIB port. Regards, Tom - Original Message - From: "Russ Ramirez" To: "Discussion of precise voltage measurement" Sent: Monday, February 20, 2017 2:26 PM Subject: Re: [volt-nuts] Basic question concerning voltage references My question is partly based on a real situation where I have 3 DMMs of decent quality Keithley 2000, 34970A (34401A), and 3457A that all agree with a good quality voltage reference that is exceeding its ppm/degree C spec as far as I am able to tell. I felt that this was telling me that I would need a 3458A to know how much closer to 10V the reference was at this point. A quick calculation of 20 bits of ADC for example told me that I was looking at 9.5 uV of resolution, or 0.6 uV at 24 bits *noise free*, etc. so it did not seem to be entirely unreasonable to see the LSD of a 6 1/2 digit DMM be higher than 1 or 2 counts. Russ On Mon, Feb 20, 2017 at 12:57 PM, m k wrote: On 20/02/2017 18:46, Russ Ramirez wrote: > I very much enjoy what is shared here. It has led me down the path of > learning more about Metrology in general and the pointers to Flukecal site > from here are appreciated. > > My question is this. If I measured a 10 volt reference known to be good to > 8 1/2 digits, but with the LSD being > 0, assuming a transfer standard with > traceability and documented uncertainties etc, would a 6 1/2 digit > voltmeter read 10.0 volts, or round up to the limits of its AD > converter resolution; say X uV over 10.0 volts? > > I hope this is not too basic a question. > > Russ > ___ > Hi Russ, some voltmeters will supply extra digits in the output they provide, but whether they are of any use depends upon how stable the reference is in that particular 6.5 digit dvm, unfortunately it needs a dvm with better capability to prove if those digits are believable. ___ 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] fluke 731b battery pack
If they are integrated with the device, the manufacturer must certify they have tested the device and proved it can not cause a fire. If you change the NiCd battery to a LiFe system, you will fail that requirement. When you ship, you must certify there is no hazmat item in your package. There is a minimum Wh capacity allowed but I am not sure what it is. Not much from memory. - Original Message - From: "David" To: "Discussion of precise voltage measurement" Sent: Wednesday, August 03, 2016 5:29 PM Subject: Re: [volt-nuts] fluke 731b battery pack Does that restriction apply to batteries which are integrated with a device? I thought it only applied to separate cells. On Wed, 03 Aug 2016 17:20:00 -0400, you wrote: I like the LiFe idea except for the restrictions on shipping by air or USPS. That shouldn't be too much of a problem for most that have access to a local cal lab. ___ 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 731b battery pack
I like the LiFe idea except for the restrictions on shipping by air or USPS. That shouldn't be too much of a problem for most that have access to a local cal lab. - Original Message - From: "David" To: "Discussion of precise voltage measurement" Sent: Wednesday, August 03, 2016 5:08 PM Subject: Re: [volt-nuts] fluke 731b battery pack On Wed, 3 Aug 2016 16:34:31 -0400, you wrote: Eric wrote: NiMH cells seem to work in the 731b so I'd prefer to use them over NiCd because of the higher capacity and lower toxicity of potential leaks. Is there a downside to doing this? In my experience, good NiCDs are preferable to NiMHs. Good NiCds have substantially lower self-leakage than NiMHs (this is true even of the "NEW!! Low-discharge!!" NiMHs). NiCds also don't degrade nearly as fast if they are left too long on trickle charge. Both of these features translate directly into increased life for the NiCds. NiCds are also quieter, and capable of larger current drains, due to their lower internal (series) resistance (high current is not really an issue in your application). That is my experience as well however I do like the better low discharge NiMH cells. Some are better than other though. Consumer-type NiCds may suffer from the problem PHK noted (poor quality due to low production volumes), but there are still many industrial and military applications that specify NiCDs for some or all of the reasons given above. Excellent NiCds are readily available -- just look for aerospace-grade parts rather than consumer batteries. Low leakage and high temperature NiCd cells seem to last a lot longer than other types and you will not find any consumer versions of these but the price is high. Many built-in charging circuits are crude and leave the batteries on a trickle current that is really too high, particularly given the temperatures inside electronic instruments. So whichever batteries you choose, plan on redesigning the charging circuit. That brings up the possibility of using either LiFePO4 or SLA (sealed lead-acid) batteries -- if you have to redesign the charging circuit anyway, you can just as easily design it for LiFePO4 or SLA. I have not evaluated the 731B power supply in particular, but LiFePO4 would be my presumptive choice unless I encountered an insurmountable obstacle. Best regards, Charles I looked at the schematic and is seems feasible without excessive effort. Either the existing simple series preregulator can be modified or replaced allowing it to both charge the battery (through a blocking diode) and power the instrument or a completely separate power charging circuit can be added in parallel. The difficulty of maintaining charge in a backup application using NiMH cells would lead me to consider LiFePO4 cells instead. The only serious difficulty would be preventing excessive discharge which will ruin a lithium (or PbSO4) based rechargeable battery in short order. ___ 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 731b battery pack
NiMH does not do too well in float charge conditions and that is the main state a 731B will spend its time. Regards, Tom - Original Message - From: "Eric Garner" To: "Discussion of precise voltage measurement" Sent: Wednesday, August 03, 2016 1:27 PM Subject: [volt-nuts] fluke 731b battery pack So I managed to get one of the Fluke 731b's mentioned on the list a while back. It was a little more chewed up than the description in the auction led me to believe: https://plus.google.com/u/0/112871219575380932919/posts/iDWyzwYYRdj?pid=6314634305601690930&oid=112871219575380932919 but it appears to be functional. The NiCd pack appears to have leaked some time in the past and was removed, which is fine since I was going to replace the batteries anyway. Looking through the archives, replacement battery packs for the 731b has been a popular topic but I have some questions that remain open. 1. NiMH cells seem to work in the 731b so I'd prefer to use them over NiCd because of the higher capacity and lower toxicity of potential leaks. Is there a downside to doing this? 2. If I go with NiMH, is there a manufacturer that's prefered? reading reviews of NiMH cells online leads me to believe that some manufacturers (Tenergy) have lower quality and are less reliable. 3. If I go with NiCd would you expect problems if I used larger cells (4/5A vs 2/3A) thanks --Eric _ Eric Garner ___ 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] Load Testing a PSU
You are mixing the terms "shunt" and "load" I believe in error. The shunt is not a load. It would be in series with the load. - Original Message - From: "Stan, W1LE" To: Sent: Tuesday, May 17, 2016 12:47 PM Subject: [volt-nuts] Load Testing a PSU Hello The Net: Every test bench needs an assortment of current shunts. Some of mine are: 100 Amps will give a 50 millivolt drop across it at 100A load.. Another is a 50 Amp shunt that gives 50 millivolts across it when loaded to 50A. Then use a DVM to measure the voltage drop. Also have a FLUKE current probe "clamp on" using a Hall effect technique, to measure AC and DC current. A Ebay search should give some cost effective results for a current shunt, just for an idea. Stan, W1LECape Cod FN41sr z ___ 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] Just back from cal
You really won't know what is going on until you do the next calibration cycle and examine the as received data for both units. Or find someone with a better meter or reference and compare them. Who did the calibration? You might leave both units powered up for a few days/weeks and see how they behave together. Also, you are two degrees C above you lab calibration temperature. That could add to the uncertainty. - Original Message - From: "Joseph Gray" To: "Discussion of precise voltage measurement" Sent: Thursday, April 07, 2016 11:20 PM Subject: [volt-nuts] Just back from cal In February, I sent my HP 3457A in for cal. In late March, I sent my EDC VS330 DC Voltage Reference in for cal. Today, I just got the VS330 back and thought I'd compare the two instruments. Both instruments have been on for a couple of hours. It is about 25 C in the room. Setting 10.0 on the VS330, I measure 9.99891 VDC on the 3457A. According to the manual, on the 30 VDC range, the 90 day spec is 0.0035% of reading, plus 19 counts. The VS330 lists the "Limit of error accuracy" as 0.003% of setting plus 0.001% of range (30 V range). The "Calibration accuracy" is 0.002% of setting plus 0.0005% of range. Now, if we take the worst case for both instruments, what I am reading is marginally inside the total error for both instruments. However, considering that both instruments were recently calibrated and adjusted, I would expect much better. The report on the 3457A, dated 16 Feb says the 30 VDC range read 29.9991 VDC. The report on the VS330, dated 31 Mar says 10 VDC read 10.0001 VDC. Both instruments required adjustment. These numbers would lead me to believe that I should be getting a lot closer agreement to 10 VDC for both of these instruments. Am I expecting too much? Joe Gray W5JG ___ 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] Wanted - UK source of a replacement battery (type LX 1634) for HP 3457A 6.5 digit multimeter
Looking through the service manual I don't see a connection from the battery to the NVRAM. I am sure I measured battery voltage on pin28 so I suspect a schematic error. Can someone that has one open verify that? My 3457 is in cal and I prefer not to break the seals. - Original Message - From: "Mark Sims" To: Sent: Sunday, January 24, 2016 7:36 PM Subject: [volt-nuts] Wanted - UK source of a replacement battery (type LX 1634) for HP 3457A 6.5 digit multimeter Although I have not done this on a 3457A, I have done it on other devices: Take new 3.6V battery. Solder silicon diode to new battery lead (near the cell) to drop voltage to 3.0ish volts. Solder battery / diode to existing battery leads (near the circuit board). Cut old battery free. ___ 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] New member with 3457A problem
That looks like a good one from what I can see. It would be nice to check it out in person to see if the display has any dim digits. Looking at the picture seems to show it has some dimming compared to the manual range indicator. The price is pretty good also. Maybe they might negotiate down slightly. It would run you about $600+ to send in for a Keysight calibration. Nice work on finding the problem with your 3457A. - Original Message - From: "Jerry Hancock" To: "Discussion of precise voltage measurement" Sent: Tuesday, January 05, 2016 8:06 PM Subject: Re: [volt-nuts] New member with 3457A problem Hello again, Just for the record, after spending another dozen or so hours on this problem, I found U216, “Precharge offset adj” to have a low resistance from pins 1,5,6 to pin 4, essentially one of the 4 transistors in the CA3096 is shorted (11.28 ohms) though not completely. I found this by scoping the signal coming into the input amplifier at pin 10 of U101, “Input Hybrid”, while putting the meter into an auto cal loop. This problem was difficult to track down as unlike the other Service Manuals, there are no waveforms available in the 3457a manual. I noticed that during the precharge cycle the waveform was taking a large negative dive instead of two relatively equal pulses, one that reads the signal and the other during precharge, I assume. This negative voltage from the precharge offset was then not being drained efficiently when the leads were open resulting in a negative to zero open voltage displayed on the meter compared to the typical ~+2.5V. So for the record, if you get a “0 Hardware error” followed by a 512 or 560 (512 + 32 + 16 errors signaled) in reply to the “auxerr?” command, take a look in the area of U216 and check the four transistors that are in the CA3096E. Lastly, as I commented on another site, after reading through the 3457a theory of operations, that there are a number factors that need to be calibrated out of a meter to ensure accuracy and repeatable measurements. In this case, obviously the input amplifier needs to have a stable offset voltage (zero). The precharge offset charges the approximate 10pf of stray capacitance out of the input amplifier to keep it from impacting the readings. In conclusion, it takes more than an accurate ADC, gain resistors, etc to make a good meter. I followed a number of threads where people were attempting to make their own 5.5 digit meter, I played around with some circuits myself, but nowhere did I see stray capacitance taken into account. Thank you for reading. By the way, there is what looks like a nice 3458a on craigslist in the SF Bay area. Initial price of $2,900 was dropped last night to $1,950. I wish I had some leftover cash from Christmas! Jerry On Jan 3, 2016, at 6:26 PM, Jerry Hancock wrote: I’ve been reading the list for a while, never had a reason to post until now. I have an HP 3457a, actually two of them, both work great, accurate, stable, etc., except one won’t autocal without an error 512 in auxerr - ohms recharge offset. I’ve had the meters side by side for hours the past few days and can’t seem to locate the problem. There is a difference in the Ohms precharge offset in the failing meter. It looks like a factor mod was performed to lower U216 below +15 by adding resistors to legs 13 and 10. I know there were service notes sent out by HP in 1992 related to the 512 error. the other thing of note is that occasionally when I power on the meter, it will also get a 16 error, which is the offset. I ran diagnostic 4 and calibrated the offset but occasionally the meter will not pass the test no mater how the offset it adjusted. For those of you not familiar, the diagnostic 4 puts the meter in a loop displaying HI or LO depending on the adjustment until the repair tech (me in this case) adjusts the offset correctly. At that point the meter displays ‘Passed’. When the meter fails, usually when cold, the display oscillates between HI/LO like the ADC doesn’t have a connection and the input is floating. I tried swapping U101, the input hybrid, between the two units without luck. So I am wondering if anyone on the list has run into this problem in the past, and if so, the solution would be appreciated. Thanks. By the way, I have a number of voltmeters, can’t seem to get enough, and am pretty good with 3455A repairs having four of them. My black face 3455A is one of my favorites. I also have 2 x 3456A, 2 x 3457A, 3 x 3478a, 2 x 3476, a bunch of Keithely (191, 178, 199, 195, 196, etc) and others, mostly older HP units like the 400. I am currently eyeing a 3458a. I guess I am a volt-nut at heart. ___ 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] Wavetek 1281 - Calibration Key
- Original Message - From: "Todd Micallef" To: "Discussion of precise voltage measurement" Sent: Sunday, November 01, 2015 8:23 PM Subject: Re: [volt-nuts] Wavetek 1281 - Calibration Key Unfortunately, when I had my keys made for the 4700, I took the lock out of a broken 1071 to the locksmith. I originally showed them photos of an actual key and they looked at me like I was crazy. I could only find two locksmiths near me for the 4700 and a Valhalla 2724A. Both wanted a lock before they would try to brute force a new key. It appears that the locks are different with the Wavetek gear. I have already sent a message to the seller of the 1271 and I hope to hear something soon. If not, I will desolder the wires and remove the lock and carry it to one of the locksmiths. At least they only charged me $10 for the time and two keys for my Valhalla. On Sun, Nov 1, 2015 at 12:32 PM, gilb...@nickgilbert.org < gilb...@nickgilbert.org> wrote: Assuming the Wavetek branded meters use the same key as the Datron, the link below is a 1071 cal/service manual from KO4BB, which has a really good photocopy of the calibration key on the last page. Print on cardstock, sharpie the notches on a suitable blank, take the marked blank to a locksmith or cut yourself. Better yet, see if the other seller will send you some photos of the 1271 key. Same process applies. I just gave a locksmith the picture and he did all the leg work for $15 and I had it same-day. Sometimes there is a number and a name on the key. Googleing the number will sometimes find a like key. Also, a locksmith may also be able to find a copy. ___ 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 5200A instability...
How about any aluminum electrolytics that might be used for coupling capacitors? I had a problem with a DC reference that had some aluminum electrolytic caps that were leaky and caused feedback problems. If memory holds, they were in the 10 to 30 uF range. Just a thought. Tom - Original Message - From: "Chuck Harris" To: "Discussion of precise voltage measurement" Sent: Tuesday, July 28, 2015 11:35 PM Subject: [volt-nuts] Fluke 5200A instability... Before I spend a lot more time on it, does anyone have any experience with the Fluke 5200A's feedback loop oscillating when in the 100Hz band position? Mine started to oscillate at about a 1/2Hz rate a while back. It is two to three orders of magnitude better when in the 1KHz and higher band positions. I can tell it is oscillating because if I watch the 3 least significant digits on my 3456A voltmeter, in the AC position, they keep repeating over and over and over... sort of fits a 1-2-3-1-2-3... count. I have replaced the bad capacitors in the power supply, and on a few of the boards. I have checked the supplies for voltage and ripple, and AFAIK they are ok. I tested the 2uf mylar integrator cap that is employed while in the 100Hz band, and replaced more than a few carbon composition resistors that were between 20 and 50% out of tolerance with no apparent affect. The carbon composition resistors I replaced were used to digitally adjust the gain of the integrator, so seemed likely to have an effect on the stability criterion of the feedback loop.. The DC Reference voltage seems to be very stable, and can be selected up and down with the voltage selection switches. I have tested all of the tantalums for shorts, and found none. I am running out of ideas. TIA, -Chuck Harris ___ 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] Oven thermal insulation
You might look at AeroGel. Example here. http://www.ebay.com/itm/Aspen-Aerogel-SPACELOFT-Insulation-Hydrophobic-Mat-10-x-14-Sample-10mm-/171203844436?pt=LH_DefaultDomain_0&hash=item27dc8b5954 - Original Message - From: "Randy Evans" To: Sent: Monday, July 06, 2015 8:43 PM Subject: [volt-nuts] Oven thermal insulation I am working on a voltage reference deisgn that will go into an oven for the highest stability. I am looking for a good insulation material that can stand high temperatures safely (up to 80C). Looking at some HP frequency standard ovens I see a hard, light-weight insulation material of some type that looks like it would work really well, but I have no idea what it is. Does anyone have any suggestions? Thanks, Randy Evans AE6YG ___ 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 5200A extender board.
Would that be at the maximum temperature? Service would be at room temp. Sounds like a good excuse, right? - Original Message - From: "Mark Sims" To: Sent: Friday, August 29, 2014 2:28 PM Subject: [volt-nuts] Fluke 5200A extender board. Those are not holes... they are polarity markers on the silkscreen for the connectors. I do have one concern about doing the extender with ribbon cable. It is rated for 300V and three of the card slots do have 300V on them. ___ 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 5200A extender board.
Learn something new every day. Thanks. - Original Message - From: "Mike S" To: Sent: Friday, August 29, 2014 2:27 PM Subject: Re: [volt-nuts] Fluke 5200A extender board. On 8/29/2014 2:16 PM, Tom Miller wrote: Did you remove the two holes? :) You mean the two pin 1 markers on the silkscreen? ___ 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 5200A extender board.
Did you remove the two holes? :) - Original Message - From: "Mark Sims" To: Sent: Friday, August 29, 2014 1:53 PM Subject: [volt-nuts] Fluke 5200A extender board. 5200A extender cables are a go! Connectors and boards are on order (from a different board fab in Hong Kong this time). One board goes on each end of the extender. Boards are connected by a 50 pin and 40 pin ribbon cable. ___ 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 732A battery module (and possible circuitreplacement)
It might be nice to do a lithium pack including all the safety controls. The down side is you would not be able to ship it by air. Tom - Original Message - From: "Mark Sims" To: Sent: Monday, August 25, 2014 9:10 PM Subject: [volt-nuts] Fluke 732A battery module (and possible circuitreplacement) I have a 732A that is missing its battery module. Does anybody have or know of a source for a replacement? Also, would there be any interest in a replacement circuit assembly for the battery module? It would probably consist of a small board that plugs into the 2x6 pin edge connector and another small board with the ballast lamp/diode/resistor/thermistors and connections for the battery/switch/external power jack. The two boards would be connected by a short ribbon cable and would allow one to add batteries to a 732A that is missing the battery module. It would not be a complete battery module with the metal frame and backplate... ___ ___ 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] HP3458A CAL ram data dumper program
Hi Mark, Is it possible the program could create a .bin or .hex file that could be used to burn a backup NVRAM on an external programmer? I would love to have a copy if possible. While I don't yet have a 3458A, it is on my wish list awaiting the necessary funds to build up and for that once in a while good deal. Regards, Tom - Original Message - From: "Mark Sims" To: Sent: Thursday, August 21, 2014 9:33 PM Subject: [volt-nuts] HP3458A CAL ram data dumper program I have the GPIBKIT version of my HP3458A cal ram data dumper program available. If you want to try a copy shoot me an email. If it works out, I'll see if John wants to include it in the standard toolkit distribution. You will need to download GPIB tool kit from the KE5FX.COM web site, run the tool kit configuration program (PROLOGIX.EXE) to setup it up for your interface (it works with Prologix and NI compatible interfaces), copy my HP3458.EXE program to the GPIBKIT directory and run it. Check the comments at the start of HP3458.CPP for some info. Run HP3458.EXE without any command line arguments for program usage help. ___ 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] Eppley standard cell catalog ?
Yeah, it looks like a Fluke part number. Tom - Original Message - From: "Brooke Clarke" To: "Discussion of precise voltage measurement" Sent: Friday, July 25, 2014 3:07 PM Subject: Re: [volt-nuts] Eppley standard cell catalog ? Hi Pete: I don't have info on that particular number there is some info about their patents at: http://www.prc68.com/I/Eppley.html PS their standard cell bulletin has two and three digit catalog numbers. Have Fun, Brooke Clarke http://www.PRC68.com http://www.end2partygovernment.com/2012Issues.html http://www.prc68.com/I/DietNutrition.html Pete Lancashire wrote: Looking for spec's on model 705489 -pete ___ 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] Datron 1082
That will work. Don't put it in backwards or short it out and you'll do fine. Tom - Original Message - From: "T. Micallef" To: Sent: Tuesday, April 22, 2014 10:07 PM Subject: Re: [volt-nuts] Datron 1082 Randy Evans writes: The schematic of the Datron 1071 DMM seems to be very similar to the Datron 1082 but I'm sure there are differences. Unfortunately, I have not been able to locate the 1082 Service Manual with the parts lists and schematics. The 1071 manual does have a similar or identical battery but I can't find the part number in the 1071 parts list. Does anyone know the part number of the memory battery in the 1082 or 1071, or the characteristics; e.g., voltage and A-H rating? Thanks, Randy Evans AE6YG On Mon, Apr 21, 2014 at 8:32 PM, Tom Knox wrote: I popped the top off of my mothballed 1071 and it looks like a 1/2AA battery based on physical measurements. It looks like the one in the following link http://www.zbattery.com/Tadiran-TL-5151-with-tabs-1-2-AA-Lithium-Battery Todd ___ 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] Datron 1082
Can you post a picture of the battery somewhere and what is printed on it? Tom - Original Message - From: "Randy Evans" To: "Discussion of precise voltage measurement" Sent: Tuesday, April 22, 2014 3:39 PM Subject: Re: [volt-nuts] Datron 1082 The schematic of the Datron 1071 DMM seems to be very similar to the Datron 1082 but I'm sure there are differences. Unfortunately, I have not been able to locate the 1082 Service Manual with the parts lists and schematics. The 1071 manual does have a similar or identical battery but I can't find the part number in the 1071 parts list. Does anyone know the part number of the memory battery in the 1082 or 1071, or the characteristics; e.g., voltage and A-H rating? Thanks, Randy Evans AE6YG On Mon, Apr 21, 2014 at 8:32 PM, Tom Knox wrote: Sorry I wasn't clear. I think the errors you are experiencing are because the memory battery is gone, so it won't matter now, this is for saving the cal data during future replacement to avoid these problems again. Best Wishes; Thomas Knox > Date: Mon, 21 Apr 2014 19:59:29 -0700 > From: randyevans2...@gmail.com > To: volt-nuts@febo.com > Subject: Re: [volt-nuts] Datron 1082 > > Tom, > > I would think with 0.08 VDC the battery is dead and all the memory is gone. > Do you think it would make any difference if I paralleled the leads with a > new one? I don't have a parts list to know what type the battery is so > it's going to be a challenge to find a direct replacement. Wish I had > a > manual. > > Randy > > > On Mon, Apr 21, 2014 at 7:54 PM, Tom Knox wrote: > > > Randy I would say from my experience with Datron there is about 90% chance > > the battery and recal will solve the problem. I would modify the battery > > with a coupe sets of leads that are long enough so you can install a new > > while the old battery is still in circuit. > > Best Wishes; > > Thomas Knox > > > > > > > > > Date: Mon, 21 Apr 2014 19:23:35 -0700 > > > From: randyevans2...@gmail.com > > > To: volt-nuts@febo.com > > > Subject: Re: [volt-nuts] Datron 1082 > > > > > > I believe the voltages are correct but I have no schematics or > > > troubleshooting instructions to confirm. I do see what looks like > > > a > > > battery in the memory section of the 1082 and it measures 0.08 VDC. Not a > > > good sign. I am really hoping someone has a Datron 1082 Service manual > > > with schematics that they can steer me to, preferably a soft copy > > > so I > > can > > > better troubleshoot the unit. It might just need a new battery (plus a > > > re-cal) to get it going again but I hate going blind. > > > > > > Randy > > > > > > > > > On Mon, Apr 21, 2014 at 8:15 AM, Tom Knox wrote: > > > > > > > As with many products of this age the tantalum caps are a common point > > of > > > > failure in the 1082. > > > > Although this current problem sounds like a memory battery. > > > > > > > > Thomas Knox > > > > > > > > > > > > > > > > > Date: Mon, 21 Apr 2014 11:03:56 -0400 > > > > > From: cfhar...@erols.com > > > > > To: volt-nuts@febo.com > > > > > Subject: Re: [volt-nuts] Datron 1082 > > > > > > > > > > Just in case you haven't yet: Always start any investigation > > > > > with > > > > > checking the power supply for voltage and ripple. Test the > > > > > main > > > > > electrolytic capacitors for capacitance, and ESR. > > > > > > > > > > Nothing in the unit's self testing ability can be trusted if > > > > > the > > > > > power supply is putting out large amounts of ripple, or is at > > > > > the > > > > > wrong voltage. > > > > > > > > > > -Chuck Harris > > > > > > > > > > Randy Evans wrote: > > > > > > I have a Datron 1082 DMM that just recently stopped working. When > > I > > > > power > > > > > > up, it gives a "FAIL" message on the front panel. I found a > > flowchart > > > > in > > > > > > an abbreviated servicing manual that indicates it's from a failure > > of > > > > the > > > > > > "Check for uncorrupted calibration store". I Assume this likely > > means > > > > the > > > > > > cal tables are corrupted? Unfortunately, I don't have sufficient > > > > > > information (e.g., schematics) to do any further troubleshooting. > > Can > > > > > > anyone help with a complete servicing manual and/or further > > diagnostic > > > > help? > > > > > > > > > > > > > > > > > > I did download the Datron 1071DMM O&S manual from K04BB but > > > > > > I > > don't > > > > know > > > > > > how similar it is to the 1082. Can anyone comment on what > > > > > > the > > > > differences > > > > > > are? > > > > > > > > > > > > > > > > > > > > > > > > Thanks, > > > > > > > > > > > > > > > > > > > > > > > > Randy Evans > > > > > ___ > > > > > 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] 34401A Why 10M ohm default i/p resistance?
Don't forget. There is accuracy and then precision. You should not confuse the two. And many things use high voltages >1kv besides old crts. T - Original Message - From: "Brent Gordon" To: "Discussion of precise voltage measurement" Sent: Thursday, April 10, 2014 4:16 PM Subject: Re: [volt-nuts] 34401A Why 10M ohm default i/p resistance? Pure conjecture: So that the reading on the 34401A matches that on a $20 DVM. Or stated differently: So that the input impedance is the same as other DVMs. Brent On 4/10/2014 8:23 AM, Tony wrote: There is no suggestion in the specifications for the 34401A that the accuracy suffers by selecting 10G ohm input resistance on the .1 to 10V range so why would they make 10M ohm the default? I can think of very few cases where having the 10M ohm i/p resistor switched in is better for accuracy than not. On the other hand 10M is sufficiently low to produce significant errors on a 6 1/2 digit DVM for sources with resistances as low as 10 ohms. Measuring 1V divided by a 100k/100k ohm divider for example causes a .5% error - 502.488mV instead of 500.000mV. That might not be a problem but I wouldn't be surprised if this catches a lot of people out (including me) when not pausing to do the mental arithmetic to estimate the error. It's just too easy to be seduced by all those digits into thinking you've made an accurate measurement even though you discarded those last three digits. And if it's not a problem then you probably don't need an expensive 6 1/2 digit meter in the first place. It's a small point I agree but it can get irritating to have to keep going into the measurement menus to change it when the meter is turned on when measuring high impedance sources (e.g. capacitor leakage testing). It can't be to improve i/p protection as 10M is too high to make any significant difference to ESD and in any case there is plenty of other over-voltage protection. OK. it provides a path for the DC amplifier's input bias current, specified to be < 30pA at 25 degrees C, but I imagine that varies significantly from one meter to the next, and with temperature, so not useful for nulling out that error. So why would they do this? ___ 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] 34401A Why 10M ohm default i/p resistance?
Think "HV Probe". Many of the accurate ones want to see a 10 meg input. Also, some meters change input impedance depending on the selected range. T - Original Message - From: "Tony" To: Sent: Thursday, April 10, 2014 10:23 AM Subject: [volt-nuts] 34401A Why 10M ohm default i/p resistance? There is no suggestion in the specifications for the 34401A that the accuracy suffers by selecting 10G ohm input resistance on the .1 to 10V range so why would they make 10M ohm the default? I can think of very few cases where having the 10M ohm i/p resistor switched in is better for accuracy than not. On the other hand 10M is sufficiently low to produce significant errors on a 6 1/2 digit DVM for sources with resistances as low as 10 ohms. Measuring 1V divided by a 100k/100k ohm divider for example causes a .5% error - 502.488mV instead of 500.000mV. That might not be a problem but I wouldn't be surprised if this catches a lot of people out (including me) when not pausing to do the mental arithmetic to estimate the error. It's just too easy to be seduced by all those digits into thinking you've made an accurate measurement even though you discarded those last three digits. And if it's not a problem then you probably don't need an expensive 6 1/2 digit meter in the first place. It's a small point I agree but it can get irritating to have to keep going into the measurement menus to change it when the meter is turned on when measuring high impedance sources (e.g. capacitor leakage testing). It can't be to improve i/p protection as 10M is too high to make any significant difference to ESD and in any case there is plenty of other over-voltage protection. OK. it provides a path for the DC amplifier's input bias current, specified to be < 30pA at 25 degrees C, but I imagine that varies significantly from one meter to the next, and with temperature, so not useful for nulling out that error. So why would they do this? Could it be psychological? By limiting the drift caused by the i/p bias current to 300uV max when the meter is left unconnected? A voltmeter with a rapidly drifting reading (several mV/s) when not connected to anything is a bit disconcerting and would probably lead to complaints that the meter is obviously faulty to users who are used to DVMs which read 0V when open circuit - because they have i/p resistance << 10G ohms and don't have the resolution to show the offset voltage caused by the i/p bias current. Personally I'd have though that the default should be the other way round - especially given that there is no indication on the front panel or display as to which i/p resistance is currently selected. Any thoughts? What do other meters do? Tony H ___ 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] FET HP3456A
Borrow Q108 (or any of the like devices) to test your hypothesis. It is just used as a low leakage protection diode. You can replace Q108 with almost any n-ch fet. Tom - Original Message - From: "Tony Greene" To: Sent: Tuesday, April 01, 2014 10:13 PM Subject: [volt-nuts] FET HP3456A I have been troubleshooting a HP3456A voltmeter. Its giving a stange fault, but I beleive I have nailed it down. The unit is reading +10.0 volts input at +9.99661 volts. If you reverse the input, it reads correct at -10.0 volts. All other ranges read correct on either polarity. What I need is a source for the FET A20 Q109 or a suitable substitute. Its HP part number 1855-0298, it was made originally by USA mfg 02883 - Siliconix, Inc, Santa Clara, CA. It crosses to NSN 5961-01-135-1324. And Vishay has bought them and the part number is now obselete. 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] 3455A ROMS
KO4BB.com has the images for the 3455A. Here: http://ko4bb.com/manuals/index.php?dir=04)_ROM_Images_and_Drivers/HP_3455A Regards, Tom - Original Message - From: "Sam Reaves" To: Sent: Monday, March 31, 2014 10:04 AM Subject: [volt-nuts] 3455A ROMS I have a HP3455A that by all appearances has lost its cookies perhaps due to bad ROMS. Does anyone have these rom images and a procedure to replace/refresh them? Sam W3OHM ___ 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 RAM batteries - longer life if unit is continually powered?
Only on the newer (AB & AD) Dallas (Maxim) parts. All the old ones (Y) do not have that feature. Tom M. - Original Message - From: "Tom Knox" To: "Discussion of precise voltage measurement" Sent: Thursday, March 27, 2014 12:59 PM Subject: Re: [volt-nuts] 3458a RAM batteries - longer life if unit is continually powered? Date Codes can be misleading because most of this style of chip does not connect to the battery until the first power up cycle. So evl Thomas Knox Date: Thu, 27 Mar 2014 17:33:17 +0100 From: frank.stellm...@freenet.de To: volt-nuts@febo.com Subject: [volt-nuts] 3458a RAM batteries - longer life if unit is continually powered? Hi, the DALLAS datasheet specifies 10 years data retention. Quite obviously, that's the unpowered time. That time includes self discharge and RAM sustaining currents. self discharge and RAM supply current will be of the same order, i.e. < 1µA, I assume from experience. And I assume also, that those currents will vary over samples, i.e. over samples of battery and RAM. Recently, there was the case, where the CAL RAM was still alive after 24 years (instrument vintage 1989, same DALLAS date code!), but with unknown powering history. Additionally, a typical 10 years of lifetime is given also for those batteries. Therefore, in practise there will be no pronounced difference between powered / unpowered state. On the other hand, DALLAS implemented an electronic seal, so that the RAM inside the package is initially powered only after first power up. But there's no parameter in the datasheet, specifying data retention according to date code or to initial power up. The waste of energy just to extend the batteries lifetime, does not pay off. On the contrary, the MTBF time of the instrument will be consumed, the display will get bad, and here in Germany, this energy consumption would cost a fortune (meanwhile: 25+ Cents / kWh, crazy). Yes, as long the instrument is powered, the CAL RAM will not lose its content.. but what about unexpected power outages? If you save the CAL RAM and repogram a fresh one after failure, there's no need to send it to agilent. No, not any RAM error needs recalibration. Those error messages are not documented. So I've scanned the text fragments in the firmware file: RAM TEST 1 RAM TEST 2 probably refer to either to the configuration RAMs (2x32kB), andthe CAL RAM (8kB). Eror messages are: NONVOLATILE RAM HiGH /LOW CAL RAM FAILURE and known ones from other users: RAM TEST 1 HIGH / LOW So I assume, that a real failure of the cal constants only apply on message: CAL RAM FAILURE and perhaps RAM TEST 2 , as RAM TEST 1 should refer to the configuration RAMs only, HIGH to the high byte RAM, LOW to the low byte RAM. Errors of the cal RAM will manifest in additional ACAL or CAL failures. Frank ___ 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] Fluke 5100B Calibrator†Repair Help
They are MOVs. They protect the Guard circuit to chassis and outguard DC supply. Tom - Original Message - From: "David McQuate" To: Sent: Thursday, March 13, 2014 2:41 PM Subject: Re: [volt-nuts] Fluke 5100B Calibrator†Repair Help Question: are the vaporized parts varistors (usually put in series for inrush current limiting) or MOVs (placed in shunt to limit transient peak voltages)? My comments concerned the former... Dave On 3/13/2014 8:34 AM, David Smith wrote: I need some help with repairing a Fluke 5100B Calibrator. The capacitor support bracket fell into the power supply module and vaporized both varistors, RV1 and RV2. A call to Fluke tells me they no longer can supply these MOV's. According to the manual's parts list these varistors are in-house parts by Fluke. I have no way of determining a substitute part. Is there anyone that can help me identify what could be a useful replacement? Thanks, Dave - W6TE___ 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. -- Clear Stream Technologies ___ 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 5100B Calibratorþ Repair Help
Hi Dave, It looks like these are just 68 volt GE MOVs. MFR Code is 09214 - GE Fluke Part 460394 GE part V68MA3A It limits the voltage from the guard circuit to chassis ground. The unit limit is 20 V pp from the front panel. Should not be too critical. Regards, Tom - Original Message - From: "David Smith" To: Sent: Thursday, March 13, 2014 12:34 PM Subject: [volt-nuts] Fluke 5100B Calibratorþ Repair Help I need some help with repairing a Fluke 5100B Calibrator. The capacitor support bracket fell into the power supply module and vaporized both varistors, RV1 and RV2. A call to Fluke tells me they no longer can supply these MOV's. According to the manual's parts list these varistors are in-house parts by Fluke. I have no way of determining a substitute part. Is there anyone that can help me identify what could be a useful replacement? Thanks, Dave - W6TE ___ 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] A Fluke 732A: Return it or keep it?
Some laptop batteries are not allowed. Spares have some limits also. Better check because TSA will take them from you. Lithium-ion batteries (a.k.a.: rechargeable lithium, lithium polymer, LIPO, secondary lithium). Passengers may carry all consumer-sized lithium-ion batteries (no more than 8 grams of equivalent lithium content or 100 watt hours per battery). This size covers AA, AAA, cell phone, PDA, camera, camcorder, handheld game, tablet, and standard laptop computer batteries. The watt hours (Wh) rating is marked on newer lithium ion batteries and is explained in #3 below. Passengers can also bring two (2) larger lithium-ion batteries (more than 8 less than 25 grams of equivalent lithium content per battery or about 100-300 watt hours per battery) in their carry-on. This size covers the largest aftermarket extended-life laptop batteries and most lithium-ion batteries for professional-grade audio/visual equipment. Most lithium-ion batteries are below this size. - Original Message - From: "Chuck Harris" To: "Discussion of precise voltage measurement" Sent: Saturday, March 08, 2014 4:36 PM Subject: Re: [volt-nuts] A Fluke 732A: Return it or keep it? Surely that isn't true... otherwise laptop computers and cell phones wouldn't be allowed on board passenger aircraft. A laptop computer's battery would greatly exceed the power in the original 732A battery pack. -Chuck Harris Tom Miller wrote: If you change to Li-Ion, you give up the ability to ship by air or at least carry it in any passenger aircraft. You might look at the Li-Ion motorcycle batteries. They are designed to charge from a normal Pb-Ac system. Down side is a pair of them will run ~$600. They are >20 AH at 12 volts nominal. Regards, Tom ___ 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] A Fluke 732A: Return it or keep it?
If you change to Li-Ion, you give up the ability to ship by air or at least carry it in any passenger aircraft. You might look at the Li-Ion motorcycle batteries. They are designed to charge from a normal Pb-Ac system. Down side is a pair of them will run ~$600. They are >20 AH at 12 volts nominal. Regards, Tom - Original Message - From: "Tom Knox" To: "Discussion of precise voltage measurement" Sent: Saturday, March 08, 2014 10:42 AM Subject: Re: [volt-nuts] A Fluke 732A: Return it or keep it? In my humble opinion your are best off first checking for a local Cal Lab with a Josephson Junction Array Voltage Standard. You can then drop it off and pick it up your 732A. I would imagine the day of abuse during shipping has more effect on uncertainty then the rest of the year combined sitting in a controlled lab environment. And Speaking of Lab environments adding precise temp and humidity control will have a substantial effect on 732A and 3458A stability. Hooking a number of small electric heaters to PID controllers can provide even out room temperature. Also I would almost always assume the 732A is more accurate then your 3458A even if you have the 002 or HFL option. Has anyone attempted changing the battery technology to Li-Ion and redesigning the charger? I am sure you could get greatly improved battery life. Thomas Knox From: jlt...@att.net To: volt-nuts@febo.com Date: Sat, 8 Mar 2014 07:50:55 -0600 Subject: Re: [volt-nuts] A Fluke 732A: Return it or keep it? Charles, Thanks for the info on batteries. I agree, some are definitely better than others. However, I'm no 'connoisseur' of batteries yet. The 732A I got was 'unknown working condition' and I wanted the cheapest batteries I could find to test the unit and see if I could get it up and running. So far, it looks good. Do you wind up having to re-solder some of the battery wires in the battery module in order to use the 12 V 5 AH batteries or will they just swing to the other side since it appears that the (+) and (-) terminals will wind up on the same side, instead of opposite sides with the 6 V 4.5 AH batteries? I have not faced the shipping question yet, but, as David pointed out, there is an issue with shipping batteries. I suspect it could be shipped but would be ground and, therefore, need a huge battery in order to get it to the other side of the country 'hot'. I recall reading some thoughts on current drain for the unit when on batteries but I do not remember what it was. Clearly, it should be at a minimum, and therefore the battery should last the longest, when already 'hot' when removed from AC power. Has anyone done that experiment? I live in NW FL and I am not aware of Cal Labs in my neighborhood that could do the work. Atlanta, perhaps? Does anyone have a recommendation of a capable Cal facility 'close by' to NW FL? Short of sending it to Fluke or another facility, I will be limited to using my Agilent Cal'd 3458A to 'adjust' the 732A, then 'tracking' the 732A from year to year as the 3458A comes back from Cal. I paid less than Michael and more than you for my unit but it seems to work. I have seen these sell on theBay for $450 and up. Joe ___ 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] JJA progress report
How about the need for liquid He refrigeration? Will this bargain based JJA have a closed loop cooling system? Sure sounds interesting though. Tom - Original Message - From: "Joe Hobart" To: "Discussion of precise voltage measurement" Sent: Sunday, February 16, 2014 2:54 PM Subject: Re: [volt-nuts] JJA progress report Thanks to the DOD and radio waves, accurate frequency is available at most places on Earth. SPRTs and more robust Reference PRTs have been available for many years. Frequency to one part in a thousand million is easy. Measuring temperature to 0.1 degree C is also easy; controlling temperature may not be as easy. What are the frequency, temperature, and other requirements for the "inexpensive" JVS systems NIST has been developing? How many similar JVS/JJA units does a major test equipment company like Agilent or Fluke have at any one location? Joe On 2/16/2014 12:00 PM, Chuck Harris wrote: There are a host of things that will cause a JJA to be off voltage... not the least of which is temperature and frequency. Absent other standards to compare with your JJA, you are really operating in the blind. The only major advantage to the JJA, and the reason it is given primary standard status, is it relates voltage, to frequency. If the pumping frequency is offset for some reason, the voltage will be wrong by a similar amount. Do you imagine that NIST uses only one JJA to hold the nation's standard volt? -Chuck Harris Tom Knox wrote: The physics of a properly run JJA will always produce the same result so you do not need additional units for comparison. That is the point of a world wide quantum voltage standard defined as K J-90 = 483 597.9 GHz/V . Just has the Hyperfine Transition of Cesium at about 9.192631770GHz is used to define the second. What is neat about the work NIST has done recently is that it has automated the System for ease of use and reduced the price to the point that it should see much wider use in day to day metrology. Having your Agilent 3458A calibrated on a JJA may not yield much difference over a Fluke 5730A cal, but once the meter has been run a few years characterizing the A to D converter and 10VAC range would only need to be done once and could substantially improve performance. I personally think that the face of calibration will change in coming years, rather then simple time based cal periods, instruments will contain complex environmental sensor packages that will constantly monitor the instruments environment . S o calibration will be based more on the instruments exposure to extreme conditions then simple time. I bet the act of shipping has more effect on cal then years sitting in a lab. So if for example a 3458A was put in an environmental chamber on a shaker table I am sure we find that up to a certain point enviromental conditions would have little effect on cal but at some point would have a major effect. Once documented the cals would be based more on environmental exposure. In addition I am sure some environmental effects on cal are repeatable and could be documented so if monitored they could be compensated for extending time between cals. So in the future you would see your instrument display "environment conditions exceeded" "cal require", with perhaps even a display of currently instrument uncertainty. This could change the face of calibration and become a multi-billion dollar industry. Thomas Knox Date: Sun, 16 Feb 2014 07:06:18 -0700 From: n...@npgcable.com To: volt-nuts@febo.com Subject: Re: [volt-nuts] JJA progress report If Earth is subjected to a GRB strong enough to damage ground based electronics, we are all going to have much more urgent problems than wondering if a JVS is operating properly. Same for an EMP. Lightning, however, might pose a more localized and serious threat. Part of your training as an expert operator will include techniques to dissuade various critters from considering the JVS for their burial ceremonies. Carrying your best zener reference to the nearest facility with another JVS would be less expensive than buying and operating a second or third system. Joe On 2/16/2014 12:58 AM, cheater00 . wrote: How do you know the primary standard is not off? That is, how do you know it's still "primary"? Maybe a gamma ray burst from a supernova damaged some of the machinery inside, or a colony of crazy ants crawled in and died inside. D. On Sat, Feb 15, 2014 at 10:10 PM, Joe Hobart wrote: These devices are primary standards; you don't need three; you probably don't even need two. If certain conditions are met, conditions you can check/verify, they will accurately generate the desired voltages. What you will probably want are at least three good zener type voltage standards and a constant temperature environment. The three will serve as a day to day standard and reality check on the JJA. And you
Re: [volt-nuts] JJA progress report
Can we get a group buy? - Original Message - From: "Tom Knox" To: Sent: Friday, February 14, 2014 12:50 PM Subject: [volt-nuts] JJA progress report More progress has been made toward a plug and play Programmable Josephson Voltage Standard then I was aware of in some previous posts. Shortly NIST will begin selling Programmable Josephson Voltage Standard AC - DC standards that will have software to automatically calibrate (With-in the Arrays limit) products like the Agilent 3458A. This will include features like detailed characterizing the A-D converter linearity. The price will be about 300K. So we are a great deal closer then I thought to Programmable Josephson Voltage Standard for every Volt-Nut. Thomas Knox ___ 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] What made a HP3458A so expensive
Can you imagine what it would cost to get that calibrated? Tom - Original Message - From: "Bill Gold" To: "Discussion of precise voltage measurement" Sent: Saturday, January 18, 2014 5:17 PM Subject: Re: [volt-nuts] What made a HP3458A so expensive In fact if you look at a 1982 HP catalog you will see that the 3456A was selling for around $3,700 and given inflation the 3458A is still a pretty good bargain when it was introduced in 1989. In 1989 the 3456A was selling for $4,600 while the 3458A was selling for $5,900. I wonder if there will ever be a "3459A" 9.5 digit meter? With a super miniture Josehpson Junction for a reference? Bill - Original Message - From: "Tom Knox" To: "Discussion of precise voltage measurement" Sent: Saturday, January 18, 2014 1:29 PM Subject: Re: [volt-nuts] What made a HP3458A so expensive Actually in spite of it's high price I feel the 3458A represents a bargain. When it was introduced in 1989 it was $5900. A price it held for decades. Although designed in then 80's it's accuracy is still unsurpassed. The 8846A is much less expensive because it has only about a quarter the parts. With few that are hand selected and/or aged. And all though both meter have well executed designs the result is the 3458A has about a magnitude greater accuracy. And anyone in Metrology can attest to the fact that the cost of accuracy is exponential. But the thought I wanted to contribute to the dialog is the real value of the 3458A is the body of knowledge built around the thousands of 358A's some running continuously for nearly three decades. The characteristics of the 3458A are perhaps the best documented of any electronic instrument ever made. That is priceless. When comparing that body of knowledge to individual units I have found every 3458A is a little different and seem to each have their own personality. In a side note, recently I owned what appeared to be the original 3458A. I cannot remember the serial number, but it had the numbered stickers identifying the boards that can be seen in the original service manual. And it was still working flawlessly. Thomas Knox Date: Sat, 18 Jan 2014 17:41:26 +0100 From: frank.stellm...@freenet.de To: volt-nuts@febo.com Subject: [volt-nuts] What made a HP3458A so expensive Well, the 3458A now is in production for about 25 years , and only around 50k units have been sold. (That's an estimation by Joe Gellers series number collection) As the 3458A is a niche product with homeopathic series volume, the development, verification/validation, special reliability engineering, selection and burn-in measures, QA costs had to be paid per unit in the beginning. To my opinion, especially the 3458A was designed mainly for military requirements (Tamb 55°C). The military was willing to pay a premium (HP = High Price) at that time. So HP was able to realize that price. All that development budget is long paid, and after end of the Cold War, the military does not order so many devices anymore, what caused the problems of the T&M business (finally => Keysight, urgh!). But as that market is tight, competitors are few, so the price is not going down, instead it's increasing over the years, from $5900 to around $8500. It would be interesting to calcualte the BOM of the 3458A. As they use many custom specific components, it should be relatively expensive. There is no parameter in the HP3458A specifications, that the device has to be powered constantly to meet the specs. Those very high 8ppm/yr. drift might apply only during continuous operation. During power down, the LTZ should not drift at all, as the ageing mechanism is driven by temperature. But there might be (there are indeed) considerable hysteresis effects. I have set the temperature of my HP3458A to ~ 60°C, I shut it down after usage, and the periodical comparison to 3 other references shows a drift of less than 1ppm/year. Frank ___ 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] HP 3458A repair.
OOPs, disregard. I tangled it with another message. Tom - Original Message - From: "Tom Miller" To: "Discussion of precise voltage measurement" Sent: Wednesday, September 18, 2013 11:28 PM Subject: Re: [volt-nuts] HP 3458A repair. Just the one from the Agilent site. If I get one of these, I'll hit Dave up for a good copy. Thanks, Tom - Original Message - From: "J. L. Trantham" To: "'Discussion of precise voltage measurement'" Sent: Wednesday, September 18, 2013 10:54 PM Subject: Re: [volt-nuts] HP 3458A repair. Forgot to ask. Do you have the CLIP? Joe -Original Message- From: volt-nuts-boun...@febo.com [mailto:volt-nuts-boun...@febo.com] On Behalf Of John Phillips Sent: Wednesday, September 18, 2013 3:51 PM To: Discussion of precise voltage measurement Subject: Re: [volt-nuts] HP 3458A repair. I talked with Gary... it sounded more like a sales pitch like they replace relays before they failed. The date code on the cal ram is 6 years past replacement. The only problem seems to be the amplifier/attenuator flatness. He said this could be caused by caps aging and changing value. They tried calibrating the AC but it did not come withing spec so they did not update the as left data... I think if they are going to send the as left data it should be real as left or blank. This meter looks like a good meter for what I will use it for so we will not use the AC above 2MHz as if we ever did. On Wed, Sep 18, 2013 at 9:17 AM, J. L. Trantham wrote: I agree with your assessment of an 'old' meter being more desirable. I would recommend a conversation with Gary Bierman if you have not already done that. Joe -Original Message- From: volt-nuts-boun...@febo.com [mailto:volt-nuts-boun...@febo.com] On Behalf Of John Phillips Sent: Wednesday, September 18, 2013 10:45 AM To: Discussion of precise voltage measurement Subject: Re: [volt-nuts] HP 3458A repair. The meter will be here in a few days. I did buy the ram. As far as the meter age goes, unless it is a very old hardware revision, I would rather have an old meter because it is more stable. That is until it brakes. I do have before and after readings and the 4 readings are the only ones that failed. The after readings are better than the before readings. Because the 8 and 10 MHz failed we did not get a certificate but we do have a good limited calibration up to 2 MHz. Just no official cal. The cal we wanted was $1600. We will still have to pay that after the repair. From what I can tell they did not run SCAL or the before/after readings would not have matched. Like they really did not run after readings or there would have been some mismatch. On Tue, Sep 17, 2013 at 6:50 PM, J. L. Trantham wrote: > John, > > Can you give us more information? Serial number, Rev. number, CALNUM? > How much to invest will be determined by age and other condition. > > It doesn't sound like a simple CALRAM issue but changing the CALRAM is > relatively easy. I removed all three DALLAS chips in mine and > installed sockets. The CALRAM can be read with a chip programmer and > the data written to a new DALLAS chip. > > I would also call Gary Bierman at the Loveland Cal Lab and have a long > talk with him. He has a lot of insight into these meters and > generally prefers to do a component level repair rather than an > assembly level repair. The charge sounds like their standard repair > charge, no matter what the problem is, and includes a 'fresh > calibration' along with a warranty, a year I think, but Gary will be able to answer that question. > > Also, once you get the meter calibrated by Agilent (and thus prove it > is functioning normally) it will be eligible for their 'repair agreement' > which > is $178.68 per year. I would consider buying a 5 year agreement after > the repair. > > Good luck. > > Joe > > -Original Message- > From: volt-nuts-boun...@febo.com [mailto:volt-nuts-boun...@febo.com] > On Behalf Of John Phillips > Sent: Tuesday, September 17, 2013 3:36 PM > To: Discussion of precise voltage measurement > Subject: [volt-nuts] HP 3458A repair. > > Hi, > I have a 3458A that we sent to Agilent for calibration which it > failed. > Before we sent it we calibrated it and it looked good to us. The > infor. we revived led us to believe that the cal memory may have > caused the failure. > We ask that it be sent buck to us and paid half the cal charges > (about > $800) insted of the $2660.64 they wanted to repair it. We were just > going to repalce the ram in try again. > When we got the meter back it came with befor and afer data Like > before 10 volts read 9.957 and after it read 10.9 so they did > something or the meter drifted that much. > T
Re: [volt-nuts] HP 3458A repair.
Just the one from the Agilent site. If I get one of these, I'll hit Dave up for a good copy. Thanks, Tom - Original Message - From: "J. L. Trantham" To: "'Discussion of precise voltage measurement'" Sent: Wednesday, September 18, 2013 10:54 PM Subject: Re: [volt-nuts] HP 3458A repair. Forgot to ask. Do you have the CLIP? Joe -Original Message- From: volt-nuts-boun...@febo.com [mailto:volt-nuts-boun...@febo.com] On Behalf Of John Phillips Sent: Wednesday, September 18, 2013 3:51 PM To: Discussion of precise voltage measurement Subject: Re: [volt-nuts] HP 3458A repair. I talked with Gary... it sounded more like a sales pitch like they replace relays before they failed. The date code on the cal ram is 6 years past replacement. The only problem seems to be the amplifier/attenuator flatness. He said this could be caused by caps aging and changing value. They tried calibrating the AC but it did not come withing spec so they did not update the as left data... I think if they are going to send the as left data it should be real as left or blank. This meter looks like a good meter for what I will use it for so we will not use the AC above 2MHz as if we ever did. On Wed, Sep 18, 2013 at 9:17 AM, J. L. Trantham wrote: I agree with your assessment of an 'old' meter being more desirable. I would recommend a conversation with Gary Bierman if you have not already done that. Joe -Original Message- From: volt-nuts-boun...@febo.com [mailto:volt-nuts-boun...@febo.com] On Behalf Of John Phillips Sent: Wednesday, September 18, 2013 10:45 AM To: Discussion of precise voltage measurement Subject: Re: [volt-nuts] HP 3458A repair. The meter will be here in a few days. I did buy the ram. As far as the meter age goes, unless it is a very old hardware revision, I would rather have an old meter because it is more stable. That is until it brakes. I do have before and after readings and the 4 readings are the only ones that failed. The after readings are better than the before readings. Because the 8 and 10 MHz failed we did not get a certificate but we do have a good limited calibration up to 2 MHz. Just no official cal. The cal we wanted was $1600. We will still have to pay that after the repair. From what I can tell they did not run SCAL or the before/after readings would not have matched. Like they really did not run after readings or there would have been some mismatch. On Tue, Sep 17, 2013 at 6:50 PM, J. L. Trantham wrote: > John, > > Can you give us more information? Serial number, Rev. number, CALNUM? > How much to invest will be determined by age and other condition. > > It doesn't sound like a simple CALRAM issue but changing the CALRAM is > relatively easy. I removed all three DALLAS chips in mine and > installed sockets. The CALRAM can be read with a chip programmer and > the data written to a new DALLAS chip. > > I would also call Gary Bierman at the Loveland Cal Lab and have a long > talk with him. He has a lot of insight into these meters and > generally prefers to do a component level repair rather than an > assembly level repair. The charge sounds like their standard repair > charge, no matter what the problem is, and includes a 'fresh > calibration' along with a warranty, a year I think, but Gary will be able to answer that question. > > Also, once you get the meter calibrated by Agilent (and thus prove it > is functioning normally) it will be eligible for their 'repair agreement' > which > is $178.68 per year. I would consider buying a 5 year agreement after > the repair. > > Good luck. > > Joe > > -Original Message- > From: volt-nuts-boun...@febo.com [mailto:volt-nuts-boun...@febo.com] > On Behalf Of John Phillips > Sent: Tuesday, September 17, 2013 3:36 PM > To: Discussion of precise voltage measurement > Subject: [volt-nuts] HP 3458A repair. > > Hi, > I have a 3458A that we sent to Agilent for calibration which it failed. > Before we sent it we calibrated it and it looked good to us. The > infor. we revived led us to believe that the cal memory may have caused the failure. > We ask that it be sent buck to us and paid half the cal charges > (about > $800) insted of the $2660.64 they wanted to repair it. We were just > going to repalce the ram in try again. > When we got the meter back it came with befor and afer data Like > before 10 volts read 9.957 and after it read 10.9 so they did > something or the meter drifted that much. > The problem is 0.1 volt and 1.0 volts failed at 8 and 10 MHz but > passed at > 4 MHz. > 4MHZ 0.1 volt reads 0.097251 Lower Limit is 0.095930 PASSED 8MHZ 0.1 > volt reads 0.085712 Lower Limit is 0.0959 > 2 > 0 > FAILED > 10MHZ 0.1 volt reads 0.75569 Lower Limit is 0.084900 FAILED > > 4MHZ 1 volt reads 0.97272 Lower Limit is 0.95930 PASSED 8MHZ 1 volt > reads > 0.86389 Lower Limit is 0.95920 FAILED 10MHZ 1 volt reads 0.73514 Lower > Limit is 0.84900 FAILED > > The AC after readings are the same. I
Re: [volt-nuts] Fluke 735C - Information Needed
Yeah but watch out for the ebay Chinese nicads. You might test a few samples before investing much in them. I have some 4/5 C cells that are marked 2500 maH but test out at 1300 maH. Tom - Original Message - From: "Robert Atkinson" To: "Discussion of precise voltage measurement" Sent: Tuesday, September 10, 2013 2:21 PM Subject: Re: [volt-nuts] Fluke 735C - Information Needed Hi, Cell capacities have gone up. I'd buy four six cell (7.2V) 2500mAH model RC battery packs and break up as required. Smaller cells much cheaper and tags already welded. Robert G8RPI. From: J. L. Trantham To: 'Discussion of precise voltage measurement' Sent: Tuesday, 10 September 2013, 13:40 Subject: Re: [volt-nuts] Fluke 735C - Information Needed Charles, The NiCd pack (of five 'units', side by side, with each 'unit' being two 1/2 D cells stacked on top of each other) is 12 V 2.2 AH, GE Cat. No. JF 479147 8249. I suspect the '8249' is a date code and they look original. The Cal date was also Feb 82. I found 1.2 V 2.5 AH 1/2 D cells for $5.50 ea. On the internet. I would like to find a cheaper source since I need 20 of them, enough for two packs, one pack on each side of the Battery PCB. I'll also need some 'thin' heat shrink tubing to go around the 2 cell 'units'. I could also use some 'spare' 1/2 D cells for the battery packs in my 5061A's and B's. I wonder what would be better, SLA or NiCd's? The NiCd's had 'spewed' and corroded the PCB a bit but I have that cleaned up. I have seen SLA's (in UPS's) 'shrivel' and get very hot as they die. I'll have to take a look at the 732A manual to see what it's battery construction looks like. Joe -Original Message- From: volt-nuts-boun...@febo.com [mailto:volt-nuts-boun...@febo.com] On Behalf Of Charles Steinmetz Sent: Monday, September 09, 2013 11:10 PM To: Discussion of precise voltage measurement Subject: Re: [volt-nuts] Fluke 735C - Information Needed Joe wrote: I need to fabricate a couple of 12 V NiCd battery packs using 1/2 D cells Does it have NiCds now? If so, do they look original? The 732A uses SLA batteries (originally 4x 6v, but most folks replace them with 2x 12v). If it has SLAs or gel cells (or originally did), you should replace them with the same so the charger works properly. 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. ___ 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] hp3457a low voltage range behavior
It's normal. Maybe yours has a little bit higher I-offset than most. But it is > infinity input impedance on the lowest ranges. You might stick a parallel 1 G resistor across the input and see what you get. They are nice meters though. Tom - Original Message - From: "J L" To: Sent: Tuesday, September 03, 2013 7:55 AM Subject: [volt-nuts] hp3457a low voltage range behavior Hi group ! After long waiting for cheap listing with possibility to european delivery, at last win 200$ ebay "parts" hp3457a meter. Now only now need to find someone local with better equipment to check calibration :-} Meter works fine, but I'm not sure how meter must behave in low voltage bands. If I short leads it show ~1uV, thats Ok. But if leads not connected then voltage slowly creep up from zero and after about 5 min grow to +3v and meter start to click relays trying to autorange. So look like somewhere inside is ~15GOhm leak to + voltage, i try to clean board with isopropyl , but no big changes. So is it normal (I doubt...) , because 10GOhm input impedance, or something is wrong and need to repair ? Any input will be appreciated! Juris yl3cb ___ 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] (no subject)
At least the subject is correct :) - Original Message - From: "Orin Eman" To: "Discussion of precise voltage measurement" Sent: Sunday, July 28, 2013 10:34 PM Subject: Re: [volt-nuts] (no subject) Three empty messages! Cat sitting on keyboard? On Sun, Jul 28, 2013 at 7:31 PM, wb6bnq wrote: ___ 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] What really gets calibrated?
Hi guys, The "as found" measurements are most likely useful to determine if gross errors were made while the instrument was in use. Say you were using it to calibrate DMM multimeters in a production environment, you would like to know that a batch of meters went out with defective calibrations. If you are getting an instrument calibrated for the first time after replacing a NVRAM battery, there would not be a need to have that known bad data recorded. Many of the newer instruments require entering a known voltage and telling the instrument to record a calibration constant in its NVRAM. I think that is mostly correct but if not, please feel free to criticize it. Regards, Tom - Original Message - From: "J. L. Trantham" To: "'Discussion of precise voltage measurement'" Sent: Sunday, July 28, 2013 6:42 PM Subject: Re: [volt-nuts] What really gets calibrated? Joe, I agree with your analysis of 'calibration' and 'adjustment'. However, if a piece of equipment was able to meet a higher specification, I would suspect the manufacturer would have claimed that. The benefit of the 'as found' and 'as left' measurements is that it tells you not only whether the unit is 'in spec' but also where it is in the range. Might be useful. All of this, of course, is dependent of the 'quality' of the 'standard' that is used to compare with. That is probably where the price goes up and the 'metrolophilosophy' comes in. In other words, do you trust your 'cal lab'? Good luck. Joe -Original Message- From: volt-nuts-boun...@febo.com [mailto:volt-nuts-boun...@febo.com] On Behalf Of Joseph Gray Sent: Sunday, July 28, 2013 5:16 PM To: volt-nuts@febo.com Subject: [volt-nuts] What really gets calibrated? I recently had it explained to me that "calibration" is really just checking a piece of gear against a known standard, to see if it meets the manufacturers specification. If it is outside specified values, then it gets "adjusted", not "calibrated". I can see that on the part of the calibration lab, it is easier and faster to simply check that a device meets spec and not have to spend time adjusting anything. It should also be less expensive for the customer. My question is, is just meeting spec good enough? If an instrument is capable of exceeding spec, shouldn't it be adjusted to the best standard available? In other words, if spec says 2 ppm, but it can be adjusted to 1 ppm, wouldn't you want to do that? Joe Gray W5JG ___ 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] (no subject)
Can you get a service/calibration manual for it? I just sent my HP3457A out for calibration. $150 Tom - Original Message - From: "Joseph Gray" To: Sent: Sunday, July 28, 2013 5:05 PM Subject: [volt-nuts] (no subject) I just had a friend buy this for me (I don't have an ebay account). I hope I didn't make a mistake. http://www.ebay.com/itm/Electronic-Development-Corporation-EDC-VS330-VOLTAGE-STANDARD-/161069656213?nma=true&si=PiGtcBMSdSOxgbm9DhiZ6iLo1GQ%253D&orig_cvip=true&rt=nc&_trksid=p2047675.l2557 Of course, once I have it, it's the chicken and egg problem. The best I have to check it against is an HP 3478A that was last calibrated an unknown number of years ago. It has a little round sticker over the CAL switch on the front, but no dated calibration label that I can see. It came from a repair facility that closed a few years ago. Actually, the reason I was tempted to buy the VS330 was because I think the 3478A is off a bit. A while back, I built a simple 5V reference with a MAX6350. The 3478A read high. I took the reference to work and the best Fluke handheld we have was dead on (I don't remember the model right now). I made the measurement again last night and the 3478A reads 5.0026 V, with the last digit fluctuating. Room temperature was 26 C. I guess obsessing about these things has brought me here to the Volt Nuts. I have been on Time Nuts for several years. Joe Gray W5JG ___ 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] Semi-precision high resistance measurement
- Original Message - From: "Steve Byan" To: Sent: Monday, June 17, 2013 1:50 PM Subject: [volt-nuts] Semi-precision high resistance measurement Any ideas as to what's going on? How can I improve my measurement procedure to get repeatable results? Do I really need better climate control even at the 3 1/2 or 4 1/2 digit level of precision? What's with the polarity sensitivity of the 8050A resistance measurements? Suggestions and advice would be gratefully accepted. Best regards, -Steve -- Steve Byan Littleton, MA 01460 On the high value resistors, did you clean them well with 99% dry isopropyl alcohol (or maybe acetone) after you handled them? The oils on your skin are very conductive when measuring in the high megohm region. Regards, Tom ___ 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] HP3458a available (was Re: hp 3458a advice)
They might not take it in without a serial number. Regards - Original Message - From: "John Phillips" To: "Discussion of precise voltage measurement" Sent: Thursday, February 07, 2013 9:34 PM Subject: Re: [volt-nuts] HP3458a available (was Re: hp 3458a advice) You should be able to any unit repaired by Agilent as long as all the parts are there for the $3000 flat rate repair and calibration charge. On Thu, Feb 7, 2013 at 5:59 PM, J. L. Trantham wrote: Paul, The 'value' of a 3458A is based on several issues, not the least of which is supply and demand. You only have to look at theBay to get an idea of what units are selling for, both working and non-working. The fact that the unit passes it's 'Self Test' is not a guarantee that it would be able to be calibrated to published performance specs. Tha Agilent website is very useful in determining an 'upper bound' on the value. The 3458A is currently orderable and currently supported. A new 3458A (without options) is available at $9,085 and would come with a fresh calibration and warranty. Repair Per Incident is available for $2,660.64. This means that if you have a complete unit, they will repair it for that price. That also comes with a fresh calibration. I don't know if that price includes all recommended upgrades as listed in the Service Notes, of which there are 20, 6 of which list 'Modification Recommended' and one of which lists 'Modification Available'. Perhaps someone on the forum knows the answer to this. Certainly Gary Biermann at Agilent can answer this. The fact that your unit does not have a serial number sticker but instead 'MTG PROTO 27' would be concerning as to whether Agilent would consider this a 'complete 3458A', and thus a candidate for repair, or, rather, a 'prototype' or some other descriptor that would imply that it looks like a 3458A but is really not a 3458A. Both new and newly calibrated units are candidates to add a Repair Agreement, available for $178.68 per year with up to 5 year blocks available for purchase. I note you mentioned firmware REV 2,1. The current firmware is 9,1. Therefore it would appear that you have a rather old and probably not 'updated' unit. That plus the 'stored in an attic' history would be concerning about the ability to repair the unit without changing several assemblies, etc. Assuming you could get the unit repaired and updated by Agilent, complete with a fresh calibration, then the maximum value would be $9,085 minus $2,660.64 minus what ever value you place on 'new' over 'old'. Then you are left with an older unit, made in the USA, with no (or perhaps a reduced) warranty as opposed to a new unit, made in Malaysia, with a warranty. The question of whether a 'new' Malaysian unit or an 'old' American unit is better is the subject of further discussion and speculation. If the unit cannot be repaired by Agilent, then, in my opinion, the value goes down and approaches the value of the hardware, transformer, etc., with serious questions about the state and reparability of the assemblies, particularly given the 'stored in an attic' history. Gary Biermann would be very helpful in getting the history and reparability of the unit. He would be worth contacting about these issues. He works at the Loveland Calibration Facility. Hope this helps. Joe -Original Message- From: volt-nuts-boun...@febo.com [mailto:volt-nuts-boun...@febo.com] On Behalf Of Paul Fox Sent: Thursday, February 07, 2013 8:54 AM To: Discussion of precise voltage measurement Subject: Re: [volt-nuts] HP3458a available (was Re: hp 3458a advice) part of me hates to do this, but... there have been some rule-breakers that ignored the "under $350" limit, and now they've ruined it for everyone. ;-) clearly the research i did into prices for "HP3458a, needs repair" was woefully inadequate. i guess the easiest thing to do is to simply remove the "under $350" part. that way everyone's working under the same assumptions. again, sorry. local buyers still get preference. (and, if you'd like to chew me out for being a bozo, that's fine, but please do it privately. maybe i should have used ebay in the first place. lesson learned.) paul i wrote: > resurrecting a somewhat older thread -- > > it's now clear to me that i have little interest in (or time for) > resurrecting my 3458a. several people on the list were interested in > it when i first brought it up, and you were all very helpful. i'd > rather not go through the ebay hassle, and i'd rather make it > available to one of you folks first in any case. > > i've put up a small set of pictures, along with a short video of > the startup sequence at http://www.foxharp.net/hp3458a . re-reading > my original list message (below), i see that my startup video didn't > capture an error message i saw back in october. so in addition to the > "110, Calibration required -- ACAL" message in the video, i guess we > should assum
