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 cbl...@centurytel.net An: Discussion of precise voltage measurement volt-nuts@febo.com 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:volt-nuts-boun...@febo.com] On Behalf Of Charles Black Sent: Monday, 1 September 2014 3:19 AM To: b...@veritechmeasurements.com.au; 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 -- 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. --- This email is free from viruses and malware because avast! Antivirus protection is active. http://www.avast.com ___ 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 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:volt-nuts-boun...@febo.com] On Behalf Of acb...@gmx.de 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 cbl...@centurytel.net An: Discussion of precise voltage measurement volt-nuts@febo.com 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:volt-nuts-boun...@febo.com] On Behalf Of Charles Black Sent: Monday, 1 September 2014 3:19 AM To: b...@veritechmeasurements.com.au; 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 -- 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. --- This email is free from viruses and malware because avast! Antivirus protection is active. http://www.avast.com ___ 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
Re: [volt-nuts] Datron 4920M, AC Voltmeter, for sale on ebay - 1 day left
thanks, I would welcome comments on calibration too. Gesendet: Dienstag, 02. September 2014 um 12:23 Uhr Von: Stephen Grady grady.st...@gmail.com An: 'Discussion of precise voltage measurement' volt-nuts@febo.com 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:volt-nuts-boun...@febo.com] On Behalf Of acb...@gmx.de 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 cbl...@centurytel.net An: Discussion of precise voltage measurement volt-nuts@febo.com 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:volt-nuts-boun...@febo.com] On Behalf Of Charles Black Sent: Monday, 1 September 2014 3:19 AM To: b...@veritechmeasurements.com.au; 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 -- 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. --- This email is free from viruses and malware because avast! Antivirus protection is active. http://www.avast.com
Re: [volt-nuts] Datron 4920M, AC Voltmeter, for sale on ebay - 1 day left
Hello Stephen, I agree that the 4920's will often drift more than their spec after 1 year. I find it more convenient to derate them slightly - and use them wisely. Note the manual states their absolute specs are valid for 6 months, but I still maintain them on a 1 year cycle. Even when de-rated they still have very good short term stability over 10 minutes and for weeks after. On the discussion of inputs at low points in ranges, I find this is where the 4920M's will most often cause calibration failures against their specs. Perhaps optimistically, Datron has specified their absolute reading spec at, say, 3V range, to be +-30ppm of reading (40 to 20kHz) for any input from 30% to 100% of range. No floor or percentage of range limiting spec is stated. When the sad day finally arrives and I need to repair units I would resort to cannibilising parts from these 4920M's just to keep my more capable 4920 going. regards, ben. From: Stephen Grady grady.st...@gmail.com Sent: Monday, September 01, 2014 5:37 AM To: Discussion of precise voltage measurement volt-nuts@febo.com Subject: Re: [volt-nuts] Datron 4920M, AC Voltmeter, for sale on ebay - 1 day left 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:volt-nuts-boun...@febo.com] On Behalf Of Charles Black Sent: Monday, 1 September 2014 3:19 AM To: b...@veritechmeasurements.com.au; 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 -- 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. --- This email is free from viruses and malware because avast! Antivirus protection is active. http://www.avast.com ___ 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 4920M, AC Voltmeter, for sale on ebay - 1 day left
charlie, you can expand these tvcs by range resistors to work as higher voltage tvcs. if you do it right (rf-type setup) you can work up to a couple hundred khz with just minor additional error beyond its error in its orgininal voltage range. need to calibrate them however. using an attenuator is not a good idea, too unprecise. still tvcs are the most precise way to measure, if done right. pretty tme consuming though. but you need them e.g. to calibrate a 4920. adrian Gesendet: Sonntag, 31. August 2014 um 21:41 Uhr Von: Charles Black cbl...@centurytel.net An: Discussion of precise voltage measurement volt-nuts@febo.com 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:volt-nuts-boun...@febo.com] On Behalf Of Charles Black Sent: Monday, 1 September 2014 3:19 AM To: b...@veritechmeasurements.com.au; 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 -- 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. --- This email is free from viruses and malware because avast! Antivirus protection is active. http://www.avast.com ___ 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 4920M, AC Voltmeter, for sale on ebay - 1 day left
Hi Adrian, I had some trouble testing my EL 1400's with my precsion attenuator (1.2Ghz B/W) not having a small enough minimum step for easy setting. It was fairly stable though. I checked everything with my scope and it was fairly flat to 20mhz with a gentle falloff to 30mhz if I remember correctly. The EL 1400's are useable to 300mhz with corrections that I don't have. I will keep an eye out for a low priced 4920. It will have to be broken bad enough to be low priced though. Charlie On 9/1/2014 3:29 PM, acb...@gmx.de wrote: charlie, you can expand these tvcs by range resistors to work as higher voltage tvcs. if you do it right (rf-type setup) you can work up to a couple hundred khz with just minor additional error beyond its error in its orgininal voltage range. need to calibrate them however. using an attenuator is not a good idea, too unprecise. still tvcs are the most precise way to measure, if done right. pretty tme consuming though. but you need them e.g. to calibrate a 4920. adrian Gesendet: Sonntag, 31. August 2014 um 21:41 Uhr Von: Charles Black cbl...@centurytel.net An: Discussion of precise voltage measurement volt-nuts@febo.com 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:volt-nuts-boun...@febo.com] On Behalf Of Charles Black Sent: Monday, 1 September 2014 3:19 AM To: b...@veritechmeasurements.com.au; 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 -- 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. --- This email is free from viruses and malware because avast! Antivirus protection is active. http://www.avast.com ___ 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
[volt-nuts] Datron 4920M, AC Voltmeter, for sale on ebay - 1 day left
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 -- 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 4920M, AC Voltmeter, for sale on ebay - 1 day left
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:volt-nuts-boun...@febo.com] On Behalf Of Charles Black Sent: Monday, 1 September 2014 3:19 AM To: b...@veritechmeasurements.com.au; 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 -- 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. --- This email is free from viruses and malware because avast! Antivirus protection is active. http://www.avast.com ___ 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 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:volt-nuts-boun...@febo.com] On Behalf Of Charles Black Sent: Monday, 1 September 2014 3:19 AM To: b...@veritechmeasurements.com.au; 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 -- 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. --- This email is free from viruses and malware because avast! Antivirus protection is active. http://www.avast.com ___ 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.
