Any thing that helps to keep the meter at the same temp all the time helps with stability.
On Wed, Aug 22, 2012 at 12:23 AM, Fred Schneider <pa4...@gmail.com> wrote: > So this is normal, hmm, my shop can be over 30 degrees when it is a hot > summer and 15 degrees in a Cold winter so keeping it powered will not help > in my case ( i am just an amateur voltnut so climatize my room is no option. > > But The service manual describes a test were you run it at 15 degrees, > then at 38 degrees and then adjust diodecurrent until you get the best > tempco. That would imply the thing should not react much on a few degrees. > > Would it be an option to ad tempcontrol. The meter itself is a sort of > uncontrolled oven. If I add a temp sensor and find a way to keep the temp > steady the meter should stay more stable. In this case cooling would be the > best option because it gets over 45 - 50 degrees inside the meter. So it > can heats it self pretty well, The problem is temp follows the oudside > temp, so if Measure inside temp at for instance 18 or 20 degrees room temp > and cool it if the inside gets hotter then the inner temp at 20 degrees > outside, than it must be more stable. > > Maybe a piezo element from a coolerbox inside (the piezo is inside, a > coolrib and fan on theoutside. I experimented with a coolrib on the cabinet > straight above the transformer, that was allready an improvent. Or some > aluminum tubes through the cabinet. Open on one side, a box on the other > side with a fan in it sucking the air through the pipes and cooling the > inside when needed, or copper tubing where i can solder ribs on. If not > enough I can pomp water through it and keep the water in an isolated box at > 30 degrees using an aquarium heater if needed. That would cover 95% of the > year. > > Stupid idea ? > > > Fred PA4TIM > > Op 22 aug. 2012 om 03:32 heeft John Phillips <john.philli...@gmail.com> > het volgende geschreven: > > > To get better performance form you Solarton keep it a constant Hot > > temperature all the time. Do not turn it off! Do not let the room > > temperature fluctuate more than a few degrees. The more stale the better. > > Cooling in most cases will induce error. If you can keep it at 20C all > the > > time go for it but if you are more stable at 28C then 28 is better. > > > > The longer you run it the more stable it will get. We do not turn off any > > of our best meters unless we are moving them or the power gos off. > > > > > > On Tue, Aug 21, 2012 at 4:21 PM, Fred Schneider <pa4...@gmail.com> > wrote: > > > >> I looked at the DC specs of the 3457 and thats the same as the > solartron. > >> I am looking sub uV like the solartron. The 3457 does not have that. So > I > >> think, regarding your reactions and the price, i'd better first take a > look > >> at the solartron. Modify it a bit ( cooling-ribs on the outside, one on > top > >> above the transformer and one on the back where the regulators should > be ( > >> i'm told, not looked yet) maybe a fan blowing over the ribs.) replace > the > >> keylock with a switch ( i have not a good key, it works but not smooth) > >> then put banana busses instead of the back nr2 input connector on the > front > >> and replace the mainsswitch to the front. ( instead of climbing on a > hair > >> to reach the switch) > >> > >> I printed the service manual of the 7061 and i think I first do the > tests > >> ( psu, frequency, input current ect) i also noted my zero problem is > >> because I shorted both inputs but i need to short the reference and > front > >> inputs. That could explain why zero often does not work ( error, zero to > >> large or something lile that) > >> > >> I bought a Keithley 2000 last year, it was comparable to the Fluke 8046 > >> but around 400 euro cheaper. I bought it straight from Keithley > including > >> calibration. Besides that I have a keithley 196 that was just calibrated > >> when I bought it. ( and a 199) > >> > >> I was aiming for the holy grale of meters and a 3457 turns out to be a > >> whole different beast. Someone I know bought a 3456 for 225 euro, fresh > >> calibrated, that is 6,5 digits too. So i wondered why is a 3457 so much > >> more expensive. > >> > >> But I better wait and save more money in the hope to find one day an > >> affortable 3458. > >> One should always keep something to dream about :-) > >> > >> Fred > >> > >> > >> > >> > >> Fred PA4TIM > >> > >> Op 21 aug. 2012 om 22:06 heeft John Phillips <john.philli...@gmail.com> > >> het volgende geschreven: > >> > >>> you can put your 3457A into statistics mode and pick up +/- 29,999,999 > >>> counts from the display. > >>> +/- 2,999,999 counts is all you can get form the normal /live mode. > >>> > >>> On Tue, Aug 21, 2012 at 12:52 PM, J. L. Trantham <jlt...@att.net> > wrote: > >>> > >>>> Fred, > >>>> > >>>> 700 euro seems a bit high, at least by US standards, for a 3457A. It > >> is a > >>>> good meter and I have one. Though no longer supported, Agilent will > >> still > >>>> calibrate one for $200.22, according to their website. > >>>> > >>>> You might want to consider a Fluke 8846A. I have seen them sell for > >> $900 > >>>> new. I don't have one but it was going to be my next addition until I > >> got > >>>> a > >>>> 3458A. > >>>> > >>>> What is the issue with the 7061? > >>>> > >>>> Joe > >>>> > >>>> -----Original Message----- > >>>> From: volt-nuts-boun...@febo.com [mailto:volt-nuts-boun...@febo.com] > On > >>>> Behalf Of Fred Schneider > >>>> Sent: Tuesday, August 21, 2012 2:00 PM > >>>> To: volt-nuts@febo.com > >>>> Subject: [volt-nuts] HP3457 > >>>> > >>>> I have a solatron 7061 but i am not very impressed with it. Must I go > >>>> looking for an alternative or is this 7061 when i gave it a good > >> checkup / > >>>> overhaul a good meter ? > >>>> I am offered a 3457 for 700 euro and the owner, will calibrate it (he > >> has > >>>> several calibrtors, standards and a couple of 3458 meters. My > intuition > >>>> tells me to trusts him ( and that had never let me down before)) > >>>> > >>>> But he also told it is only 7,5 digit over hpib, and has 6,5 digit > >> display. > >>>> > >>>> My Keithly 2000 is 6,5 digits and over RS232 i get two digits extra. I > >> once > >>>> tried that, but that took me a lot of time to get it more ore less > >> working, > >>>> I am not so into computers and afraid I do not get it to work. > >>>> > >>>> Is it really better as my ( one year old 2000 ?) and better as my > >> Solartron > >>>> can be ? > >>>> I am afraid a 3458 is outside my budget. > >>>> > >>>> Fred > >>>> > >>>> > >>>> > >>>> Fred PA4TIM > >>>> _______________________________________________ > >>>> 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. > >>>> > >>> > >>> > >>> > >>> -- > >>> John Phillips > >>> _______________________________________________ > >>> 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. > >> > > > > > > > > -- > > John Phillips > > _______________________________________________ > > 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. > -- John Phillips _______________________________________________ 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.