Hi It can also be a blown diode in the bridge. When that happens the ripple goes way up. A quick check with a scope should tell you what’s happened. 50 Hz triangle wave = blown diode. 100 Hz triangle wave = blown cap.
Bob > On Oct 1, 2015, at 4:04 AM, Esa Heikkinen <tn1...@nic.fi> wrote: > > Anders Wallin kirjoitti: > >> I seem to get very strong spurs at 50Hz and harmonics with an old >> second-hand SRS FS710: >> http://www.anderswallin.net/2015/09/srs-fs710-noise-measurement/ >> feature or bug? Anyone looked at the powersupply and figured out what parts >> to change? > > If you live in a country with 50 Hz mains network then this sounds like a > dead capacitor in the power supply. Usually this means that it has old > fashioned linear power supply (with classic iron transformer). In that case, > replace the secondary capacitors after the rectifier bridge(s). Check > voltages with oscilloscope if you wanna see which ones, but it might be good > idea to replace them all (there should't be many of them). > > Should be very easy to fix. > > -- > 73s! > Esa > OH4KJU > _______________________________________________ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
