The 74HC series can handle 6V levels too. The 74HCT series is a 5V logic family.
On Sun, Dec 11, 2011 at 9:38 PM, Stanley <timen...@n4iqt.com> wrote: > The 74AC175 can not be subituted as the circuit needs the higher voltage > output, contact me off list if you need a few parts, or use the surface > mount PC board as these parts are still around. See options here : > http://www.ko4bb.com/dokuwiki/**doku.php?id=precision_timing:**pictic<http://www.ko4bb.com/dokuwiki/doku.php?id=precision_timing:pictic> > > Stanley > > ----- Original Message ----- From: "Azelio Boriani" < > azelio.bori...@screen.it> > To: "Discussion of precise time and frequency measurement" < > time-nuts@febo.com> > Sent: Sunday, December 11, 2011 2:15 PM > Subject: Re: [time-nuts] Subs for obsolete chips in pictic > > > Better use 74HC or 74HCT parts, the 74F should be TTL FAST parts that >> require high input current to be driven correctly. >> >> On Sun, Dec 11, 2011 at 9:04 PM, Chris Albertson >> <albertson.ch...@gmail.com>**wrote: >> >> Looking at the picric II schematic. Trying to decide on the bet >>> substitute parts for some obsolete parts. >>> >>> It uses a few 74ACxxx locic family parts that are no longer made. I >>> think the "74H" or "74F" series should work What do you think? I may >>> have to adapt an SMD part. They have to work on 5V supply and the >>> clock is 10MHz. There is also a discontinued op amp but they are >>> easy to sub. >>> >>> -- >>> >>> Chris Albertson >>> Redondo Beach, California >>> >>> ______________________________**_________________ >>> time-nuts mailing list -- time-nuts@febo.com >>> To unsubscribe, go to >>> https://www.febo.com/cgi-bin/**mailman/listinfo/time-nuts<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<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<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.