IIRC the HP3561A goes to 100 kHz. It's a well-built FFT analyzer at heart.
Dana On Sun, May 17, 2020 at 4:12 PM Taka Kamiya via time-nuts < [email protected]> wrote: > I have an HP audio FFT that starts from sub 1Hz so I can do that when I > get mine. What kind of load shall I use for this? Purely resistive load? > What kind of power? Near 100%, 50% or?? I don't know off the top of head > what the available RBW is. It's HP3561A > > --------------------------------------- > (Mr.) Taka Kamiya > KB4EMF / ex JF2DKG > > > On Sunday, May 17, 2020, 4:12:03 PM EDT, jimlux <[email protected]> > wrote: > > On 5/17/20 11:53 AM, Eric Scace wrote: > > Pro Audio Engineering announced a sale (through Friday) on its nominal > 14 Vdc 4A switching supply < > https://proaudioeng.com/products/pae-kx33-low-rfi-ac-power-supply/>. The > test results < > https://proaudioeng.com/products/pae-kx33-low-rfi-ac-power-supply/> > webpage compares noise on the DC output and noise frequency spectrum under > a variety of conditions with a lead-acid battery, an Astron linear supply, > and a variety of switching supplies from other manufacturers. > > > > I have not used this and can’t vouch for its performance. Given recent > discussions here on supplies, the analysis might be interesting. At least > the supplier has attempted to quantify the performance of its power supply > and make that information available to the prospective purchaser. > > > > It would be interesting to see comparable (or more suitable) > measurements made by others posted here. > > _______________________________________________ > > time-nuts mailing list -- [email protected] > > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > > and follow the instructions there. > > > > > Interesting.. It would have been nice to see spectrum analyzer plots > from, say, 0 to 1 MHz with a much narrower resolution BW. 1 MHz/div > with 300 kHz RBW isn't going to show the "row of discrete spurs" that > the switchers put out. > > 4mV ripple isn't bad, or at least, it's better than most of the other > switchers. The Astron linear is given as 5mV, but the scope photo > doesn't seem to show anything. At 5ms for the whole screen, you should > see some variation for over the 8.33 ms ripple period. > > > I get that they're demonstrating the performance with a specific > transceiver load - but I'd be interested in seeing measurements at zero, > 50%, and 100% load on a switcher. > > > > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. > > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. > _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
