Re: [volt-nuts] Good quality but reasonably priced 4mm plugs?
Tony, I have looked for the perfect connector for all types of measurements. I came to the conclusion that the type of measurement will dictate the type of connector. I prefer the solder type and would never consider using a screw type for any of my cables. I am sure they have an application somewhere, but it gives me peace of mind knowing that the cables won't pop out and create a hazardous situation. I have read that for low level measurements, use a direct wire connection, or a low thermal spade lug that has an air-tight crimp and then soldered for strength. This is not cheap to build, the crimp tool can be very expensive. I have found that Multi-Contact makes a good range of plugs as an alternative to Pomona. I recently purchased some of the SLS425-SE/Q for some generic sheathed cables. These are made of gold plated brass and are rated to 1kV and max 32A. These look heavy duty but not too expensive. The SLS205 series looks to be a decent low voltage test connector. I do not have any experience with these connectors but you might want to make some cheaper jumper cables for power supplies. The LK425-Z is another low voltage but higher current than the previous connector. It is the only sheathed, retractable, stackable connector that I have found from a reputable company. The silicone cable is probably the best choice of cable to use with any of these connectors. Pomona sells the cable #6733 in red and black. You may also want to consider shielded cable with an external ground/guard connection. I have a couple sets of the Fluke 5440A-7002 cables and I can tell the difference using them in high resistance measurements compared to the Pomona 5290A low thermal cables. I have been waiting to build a couple sets of Fluke 5440A-7003 test cables. I have some Belden 8719 cable, gold plated copper spade lugs from JS Willey, and some generic blue pomona patch cables that will be cut in half. The crimp tool is more expensive than all the other components. Unfortunately, I could not find a better alternative for the low ohms measurements. Check Farnell for the Multi-Contact connectors. I had no trouble finding them on the Newark site. The cost will probably be twice what you want to pay, but you can build them to your specs so you can make them as short or long as needed. Todd On Fri, Aug 15, 2014 at 7:44 PM, Tony wrote: > Can anyone recommend some decent banana plugs, preferably stackable, for > making up test leads? There don't appear to be many different types on Ebay > - the cheapest have a single screw connection which loosens off at the drop > of a hat, and in any case the plug, at 16mm, is too short for my HP 34401A. > > There are plenty of more expensive, audio type plugs which may be better > quality but almost invariably have all metal, uninsulated bodies - not good > when plugged into a high current power supply! > > I'd like some which I'd be happy to put 6, 8 or even 10amps through, eg. > for low-ohm measurements, but also be good for low level or precision > measurements. Would screwed, crimped or soldered connectors be best? I > believe crimped joints can be best for low thermal EMFs - at least until > the copper wires start to oxidise. > > I know Pomona make some decent connectors but the prices are quite steep - > I don't really want to spend more than $4 or so for a pair if possible. > Maybe I need to spend more for some low thermal EMF connectors or leads and > use cheaper ones for general purpose and higher current usage, but I'm not > prepared to spend $100 or so for a pair of low thermal HP leads. > > I'm in the UK so USA suppliers have a big disadvantage because of the high > shipping costs and the tax and customs handling charges which rarely seem > to apply to Chinese goods. > > What do you use? > > Thanks, > Tony > ___ > 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] New HP3458A
Randy, I have not been able to do accurate work with banana plugs. Too much thermal mass. For best results use copper wires into the cross holes of the banana jacks or small gold plated copper spade lugs crimped on the ends of the test leads. Cheap at Radio Shack. Both work fine. Remember to do an ACAL every time you want accuracy. I think my 3458A is about +5 PPM/C for four wire resistance (10K ohm) on differences of Temp?. Also clean your air filter and record the Temp? after so you know when to clean it again. If you try to use high impedance resistance standards (L&N Cheap ones) they will not measure correctly unless DELAY = 10 seconds on my system. Charlie On 8/15/2014 6:39 PM, Randy Evans wrote: I would like to thank everyone that replied to my query on what to look for in my "new" HP-3458. I did find that the AUTO ZERO button does work fine, thanks to Bill's comments. I had looked in the manual, just not far enough. The display is still perfectly readable but i would like it to be "perfect". I am particularly interested in the exchange display for $272 (better than $700 for a new one, as Todd suggested). Does someone have a contact number at Keysight that I could call (my experience is that one can spend a lot of time calling around until the right person is finally found). I certainly need to figure out how to copy and replace the NVRAM - I lost the calibration on my Datron 1082 by not realizing the memory backup battery died and now I need to calibrate it myself (the HP3458A should make that doable, I hope). Any suggestions would be greatly appreciated. I believe it has been covered before on Volt-Nuts and I need to go through the past discussions to find it. One question I have for the group is what should the display typically show with the input shorted? I see a reading of about -.0025 mV. That seems rather high. I tried several different banana cables (gold plated, tin plated) used to short the input terminals to see if thermocouple effects might be responsible but there was no change in the reading. Still learning. Thanks, Randy On Fri, Aug 15, 2014 at 8:06 AM, Jason Watson wrote: I've also seen excessive Guard to Low leakage when varistor RV501 has gone bad (it's located on the front/rear switch pcb and it's possible to replace it while leaving the circuit board in place if you are careful). HP/Agilent/Keysight Part number is 0837-0196, cross referenced to a Harris Corp. V430MA3A. On Fri, Aug 15, 2014 at 10:46 AM, Stephen Grady wrote: Randy, I have come across a few 3458A's that had leakage between Guard and Low when te guard is in external guard position. This was due to a leaky external guard switch and/or leaky front rear switch. This can be quickly determined by measuring resistance between guard and low with guard external. This normally in not an issue except when you are using 3458A to measure voltage with low above earth potential say in a bridge the guard low leakage will be loading other arm of the bridge. Kind Regards, Steve Grady Sydney, Australia -Original Message- From: volt-nuts-boun...@febo.com [mailto:volt-nuts-boun...@febo.com] On Behalf Of Randy Evans Sent: Friday, 15 August 2014 1:22 PM To: volt-nuts@febo.com Subject: [volt-nuts] New HP3458A I picked up a used HP3458A today, which I needed for some precision DC measurements i need to make. It passes all the self tests and the Auto Cal but is there any thing else I can check ( I have a 14 day RR). It reads a 10V standard I made within a few tens of ppm, but it's not a 732A but that is at least comforting. It also reads an ESI 10Kohm standard resistor dead on. The only problem is that the display has some faint pixels in some locations, with three in the second row for every digit location dead. Likely a pixel driver I would think. I am not too familiar with it yet but I noticed when I push the auto zero button, the display has a blinking square until I hit a measurement mode button; e.g., DCV, ACV, OHM, etc. Is this normal? Regards, Randy Evans ___ 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-nu
Re: [volt-nuts] Good quality but reasonably priced 4mm plugs?
I've used these http://www.ebay.com/itm/4mm-Solderless-Stackable-Banana-Plugs-1-Pair-Red-Black-/171030386766 connected with these wires http://www.ebay.com/itm/One-Pair-of-16-AWG-16-Gauge-Silicone-Wires-Silicon-Cables-1m-Red-1m-Black-/200893010111 and have had good luck, although I have not been doing any precision voltage work. Franky Tong is an excellent vendor, and delivery has been quite fast. He also offers a solder version of the banana plugs http://www.ebay.com/itm/4mm-Stackable-Banana-Plugs-1-Pair-Red-Black-/171062979200 . Gordon On Fri, Aug 15, 2014 at 6:44 PM, Tony wrote: > Can anyone recommend some decent banana plugs, preferably stackable, for > making up test leads? There don't appear to be many different types on Ebay > - the cheapest have a single screw connection which loosens off at the drop > of a hat, and in any case the plug, at 16mm, is too short for my HP 34401A. > > There are plenty of more expensive, audio type plugs which may be better > quality but almost invariably have all metal, uninsulated bodies - not good > when plugged into a high current power supply! > > I'd like some which I'd be happy to put 6, 8 or even 10amps through, eg. > for low-ohm measurements, but also be good for low level or precision > measurements. Would screwed, crimped or soldered connectors be best? I > believe crimped joints can be best for low thermal EMFs - at least until > the copper wires start to oxidise. > > I know Pomona make some decent connectors but the prices are quite steep - > I don't really want to spend more than $4 or so for a pair if possible. > Maybe I need to spend more for some low thermal EMF connectors or leads and > use cheaper ones for general purpose and higher current usage, but I'm not > prepared to spend $100 or so for a pair of low thermal HP leads. > > I'm in the UK so USA suppliers have a big disadvantage because of the high > shipping costs and the tax and customs handling charges which rarely seem > to apply to Chinese goods. > > What do you use? > > Thanks, > Tony > ___ > 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] New HP3458A
I would like to thank everyone that replied to my query on what to look for in my "new" HP-3458. I did find that the AUTO ZERO button does work fine, thanks to Bill's comments. I had looked in the manual, just not far enough. The display is still perfectly readable but i would like it to be "perfect". I am particularly interested in the exchange display for $272 (better than $700 for a new one, as Todd suggested). Does someone have a contact number at Keysight that I could call (my experience is that one can spend a lot of time calling around until the right person is finally found). I certainly need to figure out how to copy and replace the NVRAM - I lost the calibration on my Datron 1082 by not realizing the memory backup battery died and now I need to calibrate it myself (the HP3458A should make that doable, I hope). Any suggestions would be greatly appreciated. I believe it has been covered before on Volt-Nuts and I need to go through the past discussions to find it. One question I have for the group is what should the display typically show with the input shorted? I see a reading of about -.0025 mV. That seems rather high. I tried several different banana cables (gold plated, tin plated) used to short the input terminals to see if thermocouple effects might be responsible but there was no change in the reading. Still learning. Thanks, Randy On Fri, Aug 15, 2014 at 8:06 AM, Jason Watson wrote: > I've also seen excessive Guard to Low leakage when varistor RV501 has gone > bad (it's located on the front/rear switch pcb and it's possible to replace > it while leaving the circuit board in place if you are careful). > HP/Agilent/Keysight Part number is 0837-0196, cross referenced to a Harris > Corp. V430MA3A. > > > On Fri, Aug 15, 2014 at 10:46 AM, Stephen Grady > wrote: > > > Randy, > > > > I have come across a few 3458A's that had leakage between Guard and Low > > when > > te guard is in external guard position. This was due to a leaky external > > guard switch and/or leaky front rear switch. This can be quickly > determined > > by measuring resistance between guard and low with guard external. This > > normally in not an issue except when you are using 3458A to measure > voltage > > with low above earth potential say in a bridge the guard low leakage will > > be > > loading other arm of the bridge. > > > > Kind Regards, > > > > Steve Grady > > Sydney, Australia > > > > -Original Message- > > From: volt-nuts-boun...@febo.com [mailto:volt-nuts-boun...@febo.com] On > > Behalf Of Randy Evans > > Sent: Friday, 15 August 2014 1:22 PM > > To: volt-nuts@febo.com > > Subject: [volt-nuts] New HP3458A > > > > I picked up a used HP3458A today, which I needed for some precision DC > > measurements i need to make. It passes all the self tests and the Auto > Cal > > but is there any thing else I can check ( I have a 14 day RR). It reads > a > > 10V standard I made within a few tens of ppm, but it's not a 732A but > that > > is at least comforting. It also reads an ESI 10Kohm standard resistor > dead > > on. > > > > The only problem is that the display has some faint pixels in some > > locations, with three in the second row for every digit location dead. > > Likely a pixel driver I would think. > > > > I am not too familiar with it yet but I noticed when I push the auto > zero > > button, the display has a blinking square until I hit a measurement mode > > button; e.g., DCV, ACV, OHM, etc. Is this normal? > > > > Regards, > > > > Randy Evans > > ___ > > 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] Good quality but reasonably priced 4mm plugs?
Can anyone recommend some decent banana plugs, preferably stackable, for making up test leads? There don't appear to be many different types on Ebay - the cheapest have a single screw connection which loosens off at the drop of a hat, and in any case the plug, at 16mm, is too short for my HP 34401A. There are plenty of more expensive, audio type plugs which may be better quality but almost invariably have all metal, uninsulated bodies - not good when plugged into a high current power supply! I'd like some which I'd be happy to put 6, 8 or even 10amps through, eg. for low-ohm measurements, but also be good for low level or precision measurements. Would screwed, crimped or soldered connectors be best? I believe crimped joints can be best for low thermal EMFs - at least until the copper wires start to oxidise. I know Pomona make some decent connectors but the prices are quite steep - I don't really want to spend more than $4 or so for a pair if possible. Maybe I need to spend more for some low thermal EMF connectors or leads and use cheaper ones for general purpose and higher current usage, but I'm not prepared to spend $100 or so for a pair of low thermal HP leads. I'm in the UK so USA suppliers have a big disadvantage because of the high shipping costs and the tax and customs handling charges which rarely seem to apply to Chinese goods. What do you use? Thanks, Tony ___ 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] New HP3458A
I've also seen excessive Guard to Low leakage when varistor RV501 has gone bad (it's located on the front/rear switch pcb and it's possible to replace it while leaving the circuit board in place if you are careful). HP/Agilent/Keysight Part number is 0837-0196, cross referenced to a Harris Corp. V430MA3A. On Fri, Aug 15, 2014 at 10:46 AM, Stephen Grady wrote: > Randy, > > I have come across a few 3458A's that had leakage between Guard and Low > when > te guard is in external guard position. This was due to a leaky external > guard switch and/or leaky front rear switch. This can be quickly determined > by measuring resistance between guard and low with guard external. This > normally in not an issue except when you are using 3458A to measure voltage > with low above earth potential say in a bridge the guard low leakage will > be > loading other arm of the bridge. > > Kind Regards, > > Steve Grady > Sydney, Australia > > -Original Message- > From: volt-nuts-boun...@febo.com [mailto:volt-nuts-boun...@febo.com] On > Behalf Of Randy Evans > Sent: Friday, 15 August 2014 1:22 PM > To: volt-nuts@febo.com > Subject: [volt-nuts] New HP3458A > > I picked up a used HP3458A today, which I needed for some precision DC > measurements i need to make. It passes all the self tests and the Auto Cal > but is there any thing else I can check ( I have a 14 day RR). It reads a > 10V standard I made within a few tens of ppm, but it's not a 732A but that > is at least comforting. It also reads an ESI 10Kohm standard resistor dead > on. > > The only problem is that the display has some faint pixels in some > locations, with three in the second row for every digit location dead. > Likely a pixel driver I would think. > > I am not too familiar with it yet but I noticed when I push the auto zero > button, the display has a blinking square until I hit a measurement mode > button; e.g., DCV, ACV, OHM, etc. Is this normal? > > Regards, > > Randy Evans > ___ > 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] New HP3458A
Randy, I have come across a few 3458A's that had leakage between Guard and Low when te guard is in external guard position. This was due to a leaky external guard switch and/or leaky front rear switch. This can be quickly determined by measuring resistance between guard and low with guard external. This normally in not an issue except when you are using 3458A to measure voltage with low above earth potential say in a bridge the guard low leakage will be loading other arm of the bridge. Kind Regards, Steve Grady Sydney, Australia -Original Message- From: volt-nuts-boun...@febo.com [mailto:volt-nuts-boun...@febo.com] On Behalf Of Randy Evans Sent: Friday, 15 August 2014 1:22 PM To: volt-nuts@febo.com Subject: [volt-nuts] New HP3458A I picked up a used HP3458A today, which I needed for some precision DC measurements i need to make. It passes all the self tests and the Auto Cal but is there any thing else I can check ( I have a 14 day RR). It reads a 10V standard I made within a few tens of ppm, but it's not a 732A but that is at least comforting. It also reads an ESI 10Kohm standard resistor dead on. The only problem is that the display has some faint pixels in some locations, with three in the second row for every digit location dead. Likely a pixel driver I would think. I am not too familiar with it yet but I noticed when I push the auto zero button, the display has a blinking square until I hit a measurement mode button; e.g., DCV, ACV, OHM, etc. Is this normal? Regards, Randy Evans ___ 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] New HP3458A
Randy: The blinking square when you push auto zero is perfectly normal. It is now waiting for you to give it an answer. By pushing either the "^" up arrow or "v" or down arrow on the keypad set located below the display on the lower row left side, you will get the menu options for auto zero of "ON", "OFF" or "ONCE". You make your selection and then press the "ENTER" key on the "MENU/USER" keypad set, lower row right hand side. The 3458A has a large set of measurement options that you can select. Read the manual. These are accessed either through the IEEE-488 or the front panel keypads. You can get a refurbished "display" PCB from Keysight for $272 exchange which should cure all of your display problems. P/N 03458-66517. It is easy to replace. Read the manual. Check the Keysight website for details. SCAL is difficult to check without special equipment such as a AC/DC thermal converter. The NVRAM can be an issue depending upon the date codes on the NVRAM devices. Replacing them is time consuming but can be done. But you lose your calibration unless you can read the old ones and then program the new ones. Be sure to put in sockets when you replace the NVRAM. Why HP didn't do this is beyond me. Precision machined sockets hold the NVRAMS so tightly that it is almost impossible to get them out. Someone suggested that the weight of the NVRAM devices might allow them to come out of the sockets during shipment but I just don't see how with the proper sockets. It sounds like DC and Ohms are working OK. Passing self test is a good sign. Bill - Original Message - From: "Randy Evans" To: Sent: Thursday, August 14, 2014 8:22 PM Subject: [volt-nuts] New HP3458A > I picked up a used HP3458A today, which I needed for some precision DC > measurements i need to make. It passes all the self tests and the Auto Cal > but is there any thing else I can check ( I have a 14 day RR). It reads a > 10V standard I made within a few tens of ppm, but it's not a 732A but that > is at least comforting. It also reads an ESI 10Kohm standard resistor dead > on. > > The only problem is that the display has some faint pixels in some > locations, with three in the second row for every digit location dead. > Likely a pixel driver I would think. > > I am not too familiar with it yet but I noticed when I push the auto zero > button, the display has a blinking square until I hit a measurement mode > button; e.g., DCV, ACV, OHM, etc. Is this normal? > > Regards, > > Randy Evans > ___ > 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.
