I uploaded the user manual for the 4920 model some time ago. Of note, the 4920 was offered with option 10. This added four additional millivolt ranges. I have this meter with the option 10. I think it may be a better alternative to the 4920m if you don't need the wideband option. Some of the 4920 had an external wideband input jack, but I have not seen this adapter for sale. It appears these were designed to compete with the Fluke 540B due to its AC/DC transfer feature.
My meter has a limited calibration due to a couple ranges not meeting spec. Unfortunately, only the 4920M service manual is available. If anyone has the service manual for this, it would be appreciated. Todd Sent from my iPad > On Sep 2, 2014, at 10:17, "ben" <[email protected]> wrote: > > > > ---------------------------------------- > From: "ben" <[email protected]> > Sent: Tuesday, September 02, 2014 11:25 PM > To: "Discussion of precise voltage measurement" <[email protected]> > Subject: Re: [volt-nuts] Datron 4920M, AC Voltmeter, for sale on ebay - 1 > day left > > Hello all, > > I agree that the M version was made for military customers only, being a US > Navy contract in about 1990. Aside from the thermal converter Wideband V > input, key differences I am aware of between 4920 and 4920M are that the M > version does not have mV ranges below 0.3V, and the M version has Filter > options of only 100Hz and 10Hz (not additional 40Hz). Programming of Filter > uses different syntax too. > > After a question from another member I have scanned my paper copy of the D > 4920M Users manual, but its a bit of a mess. I will take it to work > tomorrow and re-do it again properly, then upload it to KO4BB and BAMA. > Hopefully the Calibration and Service manual will follow in short order. > > I can confirm that calibration of values 0.3V to 1000V use a thermal > converter. As well, calibration of 100mV (0.3V range) will require a > micropot and DC voltmeter. > > --- I have an alternative version of this email sitting in the Moderators > in-tray which has attached a PDF of a paper presented at MSC 1990 > conference (202kB file size). If returned to me I will find another site to > post the paper - it makes good reading. If interested please email me and > I can send it out individually. Otherwise, the whole MSC 1990 conference > proceedings, including the Datron 4920M paper, can be found here -> > msc-conf.com/wp-content/uploads/proceedings/MSC1990.pdf > > More to follow, > regards, > ben > > > > ---------------------------------------- > From: "Stephen Grady" <[email protected]> > Sent: Tuesday, September 02, 2014 7:54 PM > To: "Discussion of precise voltage measurement" <[email protected]> > Subject: 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" >> An: "Discussion of precise voltage measurement" >> 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! 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