That's a little high, a bit worse that what I remember mine being. According to the specs, you should expect about 0.1/0.6/4 uV for those ranges. So, your 10V seems a bit noisy. Question, what was your warmup time? These really take about 24 hours to fully stabilize. Do you have the service guide? There are several internal adjustments that affect the total noise, might just need tweaking. But, don't try to recalibrate the actual reference voltage unless you have a very good standard, of which a single Weston cell is not one of. I'll give mine a check. On 7/23/2014 12:00 PM, volt-nuts-request@febo.com wrote: > Hi Everyone, > > I have a problem. I bought a Solartron 7071 on Ebay. > That Voltmeter seems working properly but I think it's too noisy. > It passes Self Test and Initialize and the reading is consistent against > a Weston Cell to the µV. > But, when left with a short circuit as input the noise (maximum during 5 > min) is: > 0.2µV for 0.1V scale > 0.4µV for 1V scale > 8µV for 10V scale > > Is it acceptable? > Thanks for your help. > > Bye, > Jean-Louis > -- Bill Ezell ---------- The day Microsoft makes something that doesn't suck will be the day they make vacuum cleaners.

Hi Bill, From: "BIll Ezell" <wje@quackers.net> > That's a little high, a bit worse that what I remember mine being. So I will try to replace IC201 (ICL7650) as stated in the Service Manual. But, if it so I fear that the calibration will be lost. > Question, what was your warmup time? These really take about 24 hours to At least 48 hours. > But, don't try to recalibrate the actual reference voltage unless you have > a very good standard, of which a single Weston cell is not one of. It's a Transvolt 9154C actually (4 cells with t° stabilized at 0.01°C) but, I don't wish to calibrate it because it's still under calibration. Thanks. Bye, Jean-Louis