Hi One thing to head back to here:
What is being measured? If the DUT is "only" as good as a 10811 and you have a 3561a, an AD797 is overkill. That assumes you are running a RPD-1 or a high level mixer with buffers. There aren't a lot of oscillators on the surplus market that will need much better. Super amps are fine. They just are a bit beyond the minimum required to get going. Bob On Aug 21, 2010, at 3:47 PM, Bruce Griffiths <[email protected]> wrote: > [email protected] wrote: >> Thanks Bert >> >> >> In a message dated 8/21/2010 11:43:53 A.M. Eastern Daylight Time, >> [email protected] writes: >> >> >> >>> Wenzel Audio Amp referred to in this email. Perfect! I drive with it a >>> 3561A and a 7L5! Works for me. The only problem is getting any more >>> 2SK369. >>> Any recommendations? >>> >> NXP BF862, available from digi-key. >> > Don't these devices have relatively high flicker noise? > >> I have used it in a similar hookup with good success. Its virtue is the >> low noise voltage AND low input capacitance at the same time. >> You could deploy MANY of them in parallel until you get >> into the capacitance range of a single Interfet device. >> >> > The input capacitance is relatively noncritical in this application (phase > noise measurement) since it is shunted by the much larger output capacitance > of the low pass filter at the mixer IF port. > >> One heroic effort for audio is here: >> http://www.diy-audio-engineering.org/index.php?board=2.0 HPS5.1 >> >> I currently use 3 pairs of SSM2210 in front of a AD797. >> >> regards, Gerhard >> >> > > 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.
