Hi Gene, I don't have read the scematic yet (I will do later in the morning), but I suppose your schematic is a common source LNA.
If it's so, the ferrite on the drain it's a choke, used as a bias tee to isolate the RF portion of the circuit (the GaAs FET) from the power supply. For this purpose, you can use any ferrite bead that has an equivament impedance in the range of the kOhms in the band of interest. As an alternative, you can use a big inductance, that should do the trick. Cheers Simone - IW1FYV Il giorno 27 febbraio 2012 03:41, Eugene Crist <ejcris...@gmail.com> ha scritto: > I'm planning to build the GAAS FET Preamp for 430 MHZ that's in the 2008 > ARRL Handbook on page 14.37. One of the components on the drain of Q1 looks > like a ferrite bead. I've never used these in construction before and the > parts list doesn't specify any particular value or rating. Does anyone know > what value/rating should be used? Any info would be greatly appreciated. > > Thanks, Gene (KB3ONA) > _______________________________________________ > Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. > Not an AMSAT-NA member? Join now to support the amateur satellite program! > Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb > _______________________________________________ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
