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 <jim...@earthlink.net> 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 -- time-nuts@lists.febo.com > 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 -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there. _______________________________________________ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.