Hi Chris, I remember getting an 1.5V mercury cell with a 4 1/2 digit DVM kit, so that's about the level of stability you can achieve with such a battery. Alcaline batteries, and so on, forget about it. For a Fluke 332A, you need on the order of 5ppm uncertainty for a proper adjustment of the 10V range, so all other "references" are just gimmicks. Drift and T.C. are way too high. The only reasonable reference from Joe Geller (about 5ppm uncertainty, T.C. trimmed to near zero) is long gone, that's pityful. Anyhow, a 10V reference alone is also not sufficient for calibration. In general, you'll need linearity adjustment (requires a Kelvin Varley divider like the 720A, or a 3458A ), and 100V and 1kV range adjustment require a Reference Divider like the 752A, or again a 3458A. Therefore, instead of poking around with these mediocre 10V "references", I'd look for a possibility to get access to a 3458A, maybe there's a friendly volt-nuts nearby. Frank

The navel is not just for collecting lint, you can also temp stabilize a silver or mercury button cell there. Or in the armpit. Or up in other cavities of the body. Preferrably measure very quick or at least at the same time of day. Hendrik

On Sun, 12 Mar 2017 at 17:03, Frank Stellmach <frank.stellmach@freenet.de> wrote: > Hi Chris, > > > > Therefore, instead of poking around with these mediocre 10V > "references", I'd look for a possibility to get access to a 3458A, maybe > there's a friendly volt-nuts nearby. > > Frank > There are a number of reference boards supposedly removed from 3458As on eBay. Assuming they are non counterfeit (not necessarily a valid assumption for items on eBay), how easy would they be to integrate into a box to make a stable reference? The LTZ1000A chip is about $50 new, but to make a stable reference you need quite expensive resistors, so a used 3458A reference is attractive. But I don't know if problems making low thermal EMF joints might totally ruin the potential performance. -- Dr. David Kirkby Ph.D CEng MIET Kirkby Microwave Ltd Registered office: Stokes Hall Lodge, Burnham Rd, Althorne, Essex, CM3 6DT, UK. Registered in England and Wales, company number 08914892. http://www.kirkbymicrowave.co.uk/ Tel: 07910 441670 / +44 7910 441670 (0900 to 2100 GMT only please)

On 12/03/17 17:27, Dr. David Kirkby (Kirkby Microwave Ltd) wrote: > On Sun, 12 Mar 2017 at 17:03, Frank Stellmach <frank.stellmach@freenet.de> > wrote: > >> Hi Chris, >> >> >> >> Therefore, instead of poking around with these mediocre 10V >> "references", I'd look for a possibility to get access to a 3458A, maybe >> there's a friendly volt-nuts nearby. >> >> Frank >> > There are a number of reference boards supposedly removed from 3458As on > eBay. Assuming they are non counterfeit (not necessarily a valid assumption > for items on eBay), how easy would they be to integrate into a box to make > a stable reference? > > The LTZ1000A chip is about $50 new, but to make a stable reference you need > quite expensive resistors, so a used 3458A reference is attractive. But I > don't know if problems making low thermal EMF joints might totally ruin the > potential performance. > > > > The suspicion is that they may be genuine, but were rejects because of noise bursts. I bought one a while ago, but still not sure of its long term stability.

FYI, I bought two of these used 3458A reference boards for $85 each a few years ago and they both experience noise bursts. I plan on replacing the LTZ1000 chips on them (sometime in the near future). Randy Evans AE6YG On Sun, Mar 12, 2017 at 10:53 AM, m k <m1k3k1@hotmail.com> wrote: > > > On 12/03/17 17:27, Dr. David Kirkby (Kirkby Microwave Ltd) wrote: > > On Sun, 12 Mar 2017 at 17:03, Frank Stellmach < > frank.stellmach@freenet.de> > > wrote: > > > >> Hi Chris, > >> > >> > >> > >> Therefore, instead of poking around with these mediocre 10V > >> "references", I'd look for a possibility to get access to a 3458A, maybe > >> there's a friendly volt-nuts nearby. > >> > >> Frank > >> > > There are a number of reference boards supposedly removed from 3458As on > > eBay. Assuming they are non counterfeit (not necessarily a valid > assumption > > for items on eBay), how easy would they be to integrate into a box to > make > > a stable reference? > > > > The LTZ1000A chip is about $50 new, but to make a stable reference you > need > > quite expensive resistors, so a used 3458A reference is attractive. But I > > don't know if problems making low thermal EMF joints might totally ruin > the > > potential performance. > > > > > > > > > The suspicion is that they may be genuine, but were rejects because of > noise bursts. I bought one a while ago, but still not sure of its long term > stability. > _______________________________________________ > 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. >

Pada Selasa, 14 Maret 2017 3:24, Randy Evans <randyevans2688@gmail.com> menulis:

FYI, I bought two of these used 3458A reference boards for $85 each a few years ago and they both experience noise bursts.  I plan on replacing the LTZ1000 chips on them (sometime in the near future). Randy Evans AE6YG Hi Randy, Any particular reason why You want to replace the LTZ1000 ? Pada Selasa, 14 Maret 2017 3:24, Randy Evans <randyevans2688@gmail.com> menulis: FYI, I bought two of these used 3458A reference boards for $85 each a few years ago and they both experience noise bursts.  I plan on replacing the LTZ1000 chips on them (sometime in the near future). Randy Evans AE6YG On Sun, Mar 12, 2017 at 10:53 AM, m k <m1k3k1@hotmail.com> wrote: > > > On 12/03/17 17:27, Dr. David Kirkby (Kirkby Microwave Ltd) wrote: > > On Sun, 12 Mar 2017 at 17:03, Frank Stellmach < > frank.stellmach@freenet.de> > > wrote: > > > >> Hi Chris, > >> > >> > >> > >> Therefore,  instead of poking around with these mediocre 10V > >> "references", I'd look for a possibility to get access to a 3458A, maybe > >> there's a friendly volt-nuts nearby. > >> > >> Frank > >> > > There are a number of reference boards supposedly removed from 3458As on > > eBay. Assuming they are non counterfeit (not necessarily a valid > assumption > > for items on eBay), how easy would they be to integrate into a box to > make > > a stable reference? > > > > The LTZ1000A chip is about $50 new, but to make a stable reference you > need > > quite expensive resistors, so a used 3458A reference is attractive. But I > > don't know if problems making low thermal EMF joints might totally ruin > the > > potential performance. > > > > > > > > > The suspicion is that they may be genuine, but were rejects because of > noise bursts. I bought one a while ago, but still not sure of its long term > stability. > _______________________________________________ > 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.