> Ed > > If it helps I can send you some LTSpice schematics so that you can > simulate the circuit for yourself. > The breadboards behave as predicted by the simulations at 10MHz. > > John Miles has done some preliminary phase noise measurements on his > version. > > The transformers are wound on binocular ferrite cores. > I used some 14mm (long) cores intended for 40MHz to 220MHz (I had some) > operation in my breadboard which works well at 5MHz and 10Mhz.
You can also use an off-the-shelf Mini-Circuits transformer for low-power applications. The T13-1 was the one I tried. I'll stick some of the plots up on the web later tonight if possible. Residual PN is very good with this circuit, with a broadband floor near -170 dBc/Hz at 10 MHz, and no excess 1/f noise relative to a passive mixer. -- john, KE5FX _______________________________________________ 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.
