I've made a such pulse stretcher to render the 1ms pulse from a CMC Superstar and the 10µS pulse from a Trimble Lassen SK8 visible via an L.E.D. by using a simple 555 timer configured in a monostable fashion.
Sure it is not nanosecond precise and i'm not sure AT ALL it will react to a 20ns pulse, but for a visual monitoring, it is perfect (pulse stretched to about 30ms). 73 de Normand VE2UM Montreal, QC Canada --- John Ackermann N8UR <[EMAIL PROTECTED]> wrote: > Is your PPS signal too short to trigger your serial > port? Is that > what's troubling you, Bunkie? > > If so, the new TAPR FatPPS is the answer you've been > looking for... > > The FatPPS is a DB-9 "dongle" that implements a > pulse stretcher. Input > signals as short as 20 nanoseconds produce an output > pulse about 30 > milliseconds wide (the width can be changed by > changing a few component > values). It can be powered from the host computer's > serial port, and so > requires no external connections at all. It works > with either TTL or > RS-232 level input pulses (the output is always TTL > level), and can > invert input or output pulse polarity if needed. > > I designed the FatPPS because the ~20 microsecond > wide PPS signals from > several of my time sources (like the Z3801A GPSDO, > and HP frequency > standards) was too short to reliably work with the > serial ports on my > NTP servers. Hopefully, it will be of use to some > of you as well. > > The FatPPS is available only as a fully assembled > and tested unit, and > is shipping now. The price is $44 for TAPR members, > and $49 for > non-members. > > There are more details, and you can place an order, > at > http://www.tapr.org/kits_fatpps.html. You can view > the installation and > operations manual (which is still a work in > progress) at > http://www.tapr.org/~n8ur/FatPPS_Manual.pdf. > > Thanks for the interruption. > > John > > _______________________________________________ > time-nuts mailing list > time-nuts@febo.com > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com _______________________________________________ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts