But the seller told me he had been quoted 2100 Euros for repair, so I assume Keysight thought it needs repair, not just adjustment. Also, as far as I know, all Keysight calibration do include adjustments.
I'd like one, but don't really have the money, but I thought the price excessive. Dave Dr David Kirkby Ph.D C.Eng MIET Kirkby Microwave Ltd Registered office: Stokes Hall Lodge, Burnham Rd, Chelmsford, Essex, CM3 6DT, United Kingdom Registered in England and Wales as company number 08914892 http://www.kirkbymicrowave.co.uk/ Tel 01621'680100 / +44 1621-680100 On 16 January 2018 at 16:46, Dr. Frank <frank.stellm...@freenet.de> wrote: > David, > > that instrument on ebay is definitely from the agilent area, i.e. built > after 2000. > > It is really ok, and does not need any repair. > > Obviously, this AC range is a bit outside calibration @ 3V, 4MHz, but that > is normal after some years w/o adjustment, and not a defect at all. > Probably you know the different kinds of calibration at HPAK, obviously > they chose the cal w/o adjustment option. > > Currently, the KS server is down, otherwise one could download the full > calibration document, and check that, also the date of manufacturing . > > If you'd ever need these high frequency measurements, it's possible to do > that by means of an appropriate signal generator and a thermocouple. > > The internal LTZ1000A circuit might stabilize with age, also the internal > 40k VHP100 reference resistor might get better. > > The annual drift of the LTZ circuit is nominally 8ppm, but that is not > fully specified. > In theory, that applies only if the instrument is powered on continuosly. > If it's switched off most of the time, the LTZ chip should not age at all, > but it may show hysteresis (see AN-18, first item) > > So to my opinion, in this case it makes no difference, if you have an > older or a younger instrument. > > The rest of the circuit is either (short term) stable, or not, also mostly > independant from vintage. > Due to the regular AutoCal process, this is of no real concern, as all > these other drifts will be cancelled by the machine. > > The only component which determines the short term stability, is the ADC > ASIC. > > It might have a good T.C., from zero to max. 0.5ppm/°C, and it might have > a low timely drift in its calibration parameter CAL? 72. > > If latter is not the case, as described in AN-18, 2nd item, you really > have a monetary problem. > > But in any case, this stability risk is the same for every vintage of > instruments. > > Anyhow, I would prefer a newer unit like this one, as some other > components degenerate over time, like the un-obtainium fast comparators. > > In the end, this instrument is not cheap, especially w/o proper > adjustment. 3000$/€ would be a more reasonable price. > > Frank > > > _______________________________________________ > volt-nuts mailing list -- volt-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/m > ailman/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.