Re: [volt-nuts] Making a Reference IC

I wrote (regarding replacing the op-amp in a Fluke 731A or B voltage standard): > If you replace the op-amp with a modern precision part (I suggest the > OPA277 -- others may try to talk you into an auto-zero op-amp, but I > think that would be a mistake in this application), Attila wrote: W

Re: [volt-nuts] Making a Reference IC

今晩は,スタインメツさん、 On Sun, 13 Sep 2015 08:22:29 -0400 Charles Steinmetz wrote: > If you replace the op-amp with a modern precision part (I suggest the > OPA277 -- others may try to talk you into an auto-zero op-amp, but I > think that would be a mistake in this application), Why would this be a m

Re: [volt-nuts] Making a reference IC

I bought my used 3458A ref board on eBay about 5 years ago from a seller in CO. It is the genuine article. I can't see how or why anyone would bother to make a really good fake board (complete with Vishay metal foil resistors) with a fake LTZ 1000A and sell it for $99 If these boards were co

Re: [volt-nuts] Making a Reference IC

nuts@febo.com> Sent: Sat, Sep 12, 2015 1:58 pm Subject: [volt-nuts] Making a Reference IC I was looking at the schematics for the Fluke 731 and 732 voltage references. these, and several other brands and models of voltage references, use the same or similar reference ICs as their basis. The

Re: [volt-nuts] Making a Reference IC

FWIW-I recently contacted a seller of 3458A ref boards asking how/where he was able to get them. He claims that he received many as NOS from a closed assembly plant-you folks would know better than I if that story holds water. He also says that many are purchased when folks upgrade to the 4ppm

Re: [volt-nuts] Making a Reference IC

he industry's voltage reference chips are in the $2.00 or less >>>> single quanities with performance far exceeding anything previously >>>> available in discrete components?? >>>> >>>> >>>> >>>> >>>> -Or

Re: [volt-nuts] Making a Reference IC

or less single quanities with performance far exceeding anything previously available in discrete components?? -Original Message- From: Dave M <dgmin...@mediacombb.net> To: FEBO Volt-Nuts <volt-nuts@febo.com> Sent: Sat, Sep 12, 2015 1:58 pm Subject: [volt-nuts] Making a Reference

Re: [volt-nuts] Making a Reference IC

On 14/09/2015 12:08, Dr. David Kirkby (Kirkby Microwave Ltd) wrote: On 13 Sep 2015 09:15, "M K" wrote: There has been some of those references available second hand from ebay, mostly pulled, but some may be counterfeit, so look for sellers with pictures showing it as old.. Several sellers hav

Re: [volt-nuts] Making a Reference IC

We upgraded about 20 3458As to the 4 ppm reference for a local equipment rental co. Others may have done the same to and are selling the old boards that may be even more stable than 4 ppm because they have aged for years. The difference between references is aging and screening. On Mon, Sep 14,

Re: [volt-nuts] Making a Reference IC

In message , "Dr. David Kirkby (Kirkby Microwave Ltd)" writes: >A used 3458A fetches several thousand USD, There's actually one in france for EUR1500 right now... -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committ

Re: [volt-nuts] Making a Reference IC

On 13 Sep 2015 09:15, "M K" wrote: > There has been some of those references available second hand from ebay, mostly pulled, but some may be counterfeit, so look for sellers with pictures showing it as old.. Several sellers have more than 1, but with one photo, so you would have a hard time argui

Re: [volt-nuts] Making a Reference IC

Dave wrote: Just thinking... would it be possible to make a reference with similar characteristics with discrete components (a low tempco Zener and a transistor)? They would likely have to be closely coupled thermally and maintained at a constant temperature What criteria would apply to the se

Re: [volt-nuts] Making a Reference IC

in the $2.00 or less single quanities with performance far exceeding anything previously available in discrete components?? -Original Message- From: Dave M <dgmin...@mediacombb.net> To: FEBO Volt-Nuts <volt-nuts@febo.com> Sent: Sat, Sep 12, 2015 1:58 pm Subject: [volt-nuts]

Re: [volt-nuts] Making a Reference IC

gt;> available in discrete components?? >> >> >> >> >> -Original Message----- >> From: Dave M <dgmin...@mediacombb.net> >> To: FEBO Volt-Nuts <volt-nuts@febo.com> >> Sent: Sat, Sep 12, 2015 1:58 pm >> Subject: [volt-nuts] Making a Reference IC

Re: [volt-nuts] Making a Reference IC

with performance far exceeding anything previously available in discrete components?? -Original Message- From: Dave M <dgmin...@mediacombb.net> To: FEBO Volt-Nuts <volt-nuts@febo.com> Sent: Sat, Sep 12, 2015 1:58 pm Subject: [volt-nuts] Making a Reference IC I was looking

Re: [volt-nuts] Making a Reference IC

lt;dgmin...@mediacombb.net> To: FEBO Volt-Nuts <volt-nuts@febo.com> Sent: Sat, Sep 12, 2015 1:58 pm Subject: [volt-nuts] Making a Reference IC I was looking at the schematics for the Fluke 731 and 732 voltage references. these, and several other brands and models of voltage references

[volt-nuts] Making a Reference IC

I was looking at the schematics for the Fluke 731 and 732 voltage references. these, and several other brands and models of voltage references, use the same or similar reference ICs as their basis. The reference ICs are a Zener/NPN transistor pair on a single substrate. Please view in a fixed