thanks, I would welcome comments on calibration too.
> Gesendet: Dienstag, 02. September 2014 um 12:23 Uhr > Von: "Stephen Grady" <[email protected]> > An: "'Discussion of precise voltage measurement'" <[email protected]> > Betreff: Re: [volt-nuts] Datron 4920M, AC Voltmeter, for sale on ebay - 1 day > left > > The Datron 4920M was a special version of the 4920 made for the military, the > major difference is the M version has a 50 Ohm (N-female) wideband input and > only the N-female input for the low frequency input. Whereas the 4920 has a > Binding Post Input as well as the N-female input. I am not aware of the specs > for the wideband input but the low frequency input will be the same for both > models. > > I intend to reply in some detail soon on the calibration of these instruments > (and this will also apply to the Fluke 5790) and the principals of AC > calibration below 100mV as Charles has raised the issue of using attenuators > to do lower voltage measurements. > > Kind Regards, > > Stephen Grady > Sydney, Australia > > -----Original Message----- > From: volt-nuts [mailto:[email protected]] On Behalf Of [email protected] > Sent: Tuesday, 2 September 2014 5:54 PM > To: Discussion of precise voltage measurement > Subject: Re: [volt-nuts] Datron 4920M, AC Voltmeter, for sale on ebay - 1 day > left > > folks, > > does anybody know the difference in specs between a 4920M and the standard > 4920. No data on the web. > > thanks > > > > > Gesendet: Sonntag, 31. August 2014 um 23:41 Uhr > > Von: "Charles Black" <[email protected]> > > An: "Discussion of precise voltage measurement" <[email protected]> > > Betreff: Re: [volt-nuts] Datron 4920M, AC Voltmeter, for sale on ebay > > - 1 day left > > > > Hi Stephen, > > > > Thanks for the info on the 4920M. It might be that I should pass on > > this but it is nice to know that it is probably working. If I don't > > have the necessary items needed for calibration it might still be a > > good source uncalibrated. > > > > I was hoping that the 4920 had better minimum voltage out steps than > > my present Rigol 4062 for 3458a AC calibration. I have two EL 1400 > > 0.25V voltage thermal converters that I was trying to use in a test > > setup but they had such a low voltage range that I was forced to use > > my ATV-60 attenuator. It all kind of worked but a 0.1 db minimum step > > is a little course for easy use. The Rigol also suffers from this malady. > > > > Charlie > > > > On 8/31/2014 1:06 PM, Stephen Grady wrote: > > > Charlie, > > > > > > > > > The "Error Ur" is an under-range error; you have to apply an input above > > > 10% of the range before it will display a reading. The 4920's are a very > > > nice instrument. Their only problem is that they are all so old that they > > > are reaching the stage where some components are drifting excessively or > > > failing. I have come across 4920's that are drifting a little (more than > > > there spec) between cals (and yes they need to be cal'd annually), > > > another 4920 I came across had an intermittent failure in one of its > > > power supplies. > > > > > > Kind Regards, > > > > > > Stephen Grady > > > Sydney Australia > > > > > > -----Original Message----- > > > From: volt-nuts [mailto:[email protected]] On Behalf Of > > > Charles Black > > > Sent: Monday, 1 September 2014 3:19 AM > > > To: [email protected]; Discussion of precise voltage > > > measurement > > > Subject: Re: [volt-nuts] Datron 4920M, AC Voltmeter, for sale on > > > ebay - 1 day left > > > > > > Hi Ben, > > > > > > I am going to check this out today to find if it might be helpfull around > > > here for my AC calibration. It has an error message: "Error Ur" > > > so some fixing is going to be needed. On the back it says it's got Option > > > 80, whatever that is. > > > > > > Charlie > > > > > > > > > On 8/31/2014 5:37 AM, ben wrote: > > >> Hello all, > > >> Just a heads up. I noted there is a lonely Datron / Wavetek 4920M > > >> AC voltmeter for sale on ebay, starting at US$650 (ending in 1 day > > >> !). I have little idea of its true working state or not (picture shows > > >> it powered on). > > >> If fully working it would be a good buy for an AC voltmeter that > > >> is, I reckon, better than an HP 3458A. Only drawback with these > > >> models is the voltage input shell is always earthed, not floating. > > >> I have two of these 4920M's already, not really tempted by a third. > > >> I have a paper copies of operator, calibration, and service manual if > > >> anyone interested. > > >> > > >> regards, ben. > > >> _______________________________________________ > > >> volt-nuts mailing list -- [email protected] To unsubscribe, go to > > >> https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts > > >> and follow the instructions there. > > >> > > >> > > >> > > > > > > _______________________________________________ > > > volt-nuts mailing list -- [email protected] To unsubscribe, go to > > > https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts > > > and follow the instructions there. > > > > > > > > > --- > > > This email is free from viruses and malware because avast! Antivirus > > > protection is active. > > > http://www.avast.com > > > > > > _______________________________________________ > > > volt-nuts mailing list -- [email protected] To unsubscribe, go to > > > https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts > > > and follow the instructions there. > > > > > > > > > > > > > > > _______________________________________________ > > volt-nuts mailing list -- [email protected] To unsubscribe, go to > > https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts > > and follow the instructions there. > _______________________________________________ > volt-nuts mailing list -- [email protected] To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts > and follow the instructions there. > > > --- > This email is free from viruses and malware because avast! Antivirus > protection is active. > http://www.avast.com > > _______________________________________________ > volt-nuts mailing list -- [email protected] > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts > and follow the instructions there. _______________________________________________ volt-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts and follow the instructions there.
