Christopher Hoover wrote: > > Hey 'nuts, > > I'm looking for a good design for a 5 MHz frequency doubler. > > The Wenzel Blue Tops HF doubler is said to be based on a low phase > noise, public-domain NIST design: > > > <http://www.bluetops.com/Modules/lnhd.htm> > http://www.bluetops.com/Modules/lnhd.htm > > The LNHD is a fixed-frequency HF doubler based on a public-domain design > developed by the National Institute of Standards and Technology (NIST > <http://www.boulder.nist.gov/timefreq/> ) for superlative phase noise > performance. > > > Can anyone point me at a this design? I haven't had any luck finding it > on the web. > > I'm open to suggestions on other doubler designs, as well. > > -ch > > > _______________________________________________ > time-nuts mailing list > time-nuts@febo.com > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > > The secret is to ensure that there is adequate local RF feedback (source series resistor) during each half cycle to ensure that the flicker phase noise is suppressed whilst allowing the gate drive to switch the current between the JFETS. J310 n channel JFETs or similar devices should be satisfactory. Matching the JFETs is useful but a trimpot can be used to compensate for residual JFET mismatch.
Bruce _______________________________________________ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
