:) Sent From iPhone
> On Nov 26, 2014, at 9:20, Didier Juges <shali...@gmail.com> wrote: > > Said, > > Your drawing looks better than those by Bob Pease, and he was never > embarrassed by his :) > Thank you for your extensive contributions to time nuts > > Didier KO4BB > > >> On Tue, Nov 25, 2014 at 7:28 PM, S. Jackson via time-nuts >> <time-nuts@febo.com> wrote: >> Guys, >> >> I never expected such an intense discussion about using and buffering the >> outputs from the LTE-Lite board since the actual circuit to use can be >> quite simple. >> >> To address these questions, I drew up a simple schematic that uses a DIP-14 >> 74AC04 gate, six resistors, and two caps. Everyone who can solder should >> be able to build this simple circuit as a dead-bug type build on a >> copper-clad board. >> >> This circuit will buffer all three outputs (1PPS, TCXO RF, and Synthesixed >> RF) of the LTE-Lite eval board with CMOS 3.0V levels that can drive 50 Ohms >> terminations. For simplicity I grab the 3.0V power from the DIP-14 TCXO on >> pin 14 of that part on the eval board, even though I would strongly >> suggest to use a separate low noise 3.3V or 5V power supply to power the >> 74AC04 >> chip. >> >> You can add 100nF caps in series to the two RF signals before they feed >> into the coax output connectors for less power consumption and removing DC >> for >> instruments that don't like DC inputs. >> >> Using a single IC for the three signals will result in crosstalk between >> the signals, but it should be clear from the schematics how one could break >> up the signals by using three independent ICs to minimize crosstalk. >> >> We use this circuit in a small box here using SMT components, and it works >> really well. >> >> Excuse my horrible writing, using keyboards has made my fingers numb.. >> >> Hope that helps, >> Said >> >> _______________________________________________ >> 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. > _______________________________________________ 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.