The SRS 560 and 570, low noise voltage and current preamplifiers respectively, both use bog standard sealed lead acid batteries.
Andy Bardagjy bardagjy.com On Tue, Jul 9, 2013 at 9:26 AM, J. Forster <[email protected]> wrote: > EG&G Princeton Applied Research made a very low noise preamp unit, the > 113, which was pretty much the industry leader for years. It was often > used with Lock-In amplifiers. The unit used NiCds, I believe for that, > among other, reasons. I'd expect Ithaco and SAE have similar products. > > -John > > =============== > > > > David Kirkby wrote: > >> On 9 July 2013 04:52, Mark Spencer<[email protected]> wrote: > >> > >>> Hello, I've just reviewed the thread from earlier this year regarding > >>> low noise power supplies and some related information about the noise > >>> levels of certain batteries. Has anyone ever come across any data > >>> pertaining to the noise levels of common gelled lead acid storage > >>> batteries ? > >>> > >> Have you come across the volt-nuts list? > >> > >> https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts > >> > >> I see a bizzare review of an HP 3457A meter on utube > >> > >> http://www.youtube.com/watch?v=HfxpJCdgVwc > >> > >> where the guy determines the noise level of the 6.5/7.5 digit meter by > >> measuring the voltage of what he describes as a "general purpose lab > >> power supply". Is it me, or is it a bit dumb to try to "measure" the > >> noise level of a laboratory multimeter by using a general purpose lab > >> power supply. > >> > >> I must admit, I thought that using a battery would have been stable at > >> least short term, but it seems there is noise on a battery - something > >> I was not aware of until today. > >> > >> Dave > >> _______________________________________________ > >> time-nuts mailing list -- [email protected] > >> To unsubscribe, go to > >> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > >> and follow the instructions there. > >> > >> > > A battery is noisest when current is flowing in the battery. > > With no current flow (or electrolyte disturbance) the noise is very low. > > NIST has measured the noise of unloaded NiCd cells for example and it is > > extremely low. > > > > Bruce > > _______________________________________________ > > time-nuts mailing list -- [email protected] > > To unsubscribe, go to > > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > > and follow the instructions there. > > > > > > > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
