Hi Since the LPRO has a "noisy" 3 terminal regulator inside it, making the outside voltage quiet (as in noise density) probably will not help much.
Keeping the voltage *stable* will indeed help things. I think you need a high stability linear regulator rather than a low noise one. One other thing to think about is line isolation at both audio and RF. Most regulators have poor isolation above a few 10's of KHz. Bob -----Original Message----- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Neville Michie Sent: Wednesday, February 24, 2010 4:57 PM To: Discussion of precise time and frequency measurement Subject: [time-nuts] Low noise voltage regulators Hi, I remember a reference, probably by Bruce, that LEDS provide a low noise voltage reference. I am proposing to build a voltage regulator for a thermally controlled LPRO rubidium oscillator, with the voltage regulator being mounted on the 0.5 inch thick aluminium heat sink plate. The LEDS would also be mounted on the plate, which has controlled temperature. The LPRO has internal voltage regulation, and by running it at ~40C and 18Volts, the thermal flux within the unit is minimised as is the power demand. What I want to know is if a LM317 running on a stack of LEDs driven by the LM317 output would provide a low noise power source? What would be better? cheers, Neville Michie _______________________________________________ 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.