You are correct, my mistake ... But the SDR For the Masses circuit he is talking about uses a 5v chip (unless there are two articles with the same name) and all those chips are substitutes in the AC5OG circuit I believe he is talking about
Unless you plan on going low power portable I can't see why anyone would want to sacrifice IP3 by using a lower voltage chip especially at the bandwidths we are using for SDR ... It makes sense in something like Dan Tayloe's NC2030 where extremely low current portable operation is desired and where you limit the bandwidth (1.5Khz in the NC2030) which raises the IP3 compared to a 20-40khz (or more) bandwidth we desire for SDR By using a 5v chip I can still put a low noise high IP3 preamp (I'm fond of the balanced Norton noiseless feedback circuits ala Dallas Lankford) with a -3db 50 ohm pad between my input filters and the detector which better terminates both without sacrificing too much IP3 and dynamic range (Between filter loss and the pad I only lose about 3-4 db ) ... Plus it lowers the NF which becomes more important when using AD converters in excess of 98-99 db dynamic range which are coming more and more common JR > I'll underline that the mentioned pi3b3253 is a LVT (Low Voltage Technology) device working at 3.3Vcc with consequent logic voltage levels, differently from some other devices wrongly indicated on this thread as equivalents. > A direct substitution of such device with the indicated components can't be made without adaptation in the surrounding circuit. > > I don't know the device family used in the Tayloe circuit the 3253 is placed in (a pi5b3253, a 5Vcc level device exists too), of the receiver you mentioned, so it's up to you to verify this aspect and select the proper replacement. > > vy 73s de ik2wqi > > Andreas Troschka >
