The TrueTime XL-AK Time & Frequency Receiver does just what you want plus a few more outputs. Unfortunately they do not provide schematics in the manual.
73, Dick, W1KSZ -----Original Message----- >From: "David C. Partridge" <[EMAIL PROTECTED]> >Sent: Jul 10, 2008 1:30 PM >To: 'Discussion of precise time and frequency measurement' <time-nuts@febo.com> >Subject: [time-nuts] Frequency divider design critique request > >As I've mentioned before, I've been working on the design of a frequency >divider to go with my TB. > >The idea is 10MHz sine in from TB, output 2.5Vp-p 50% duty cycle square wave >into 50R (5V into 1M), at 10Mhz, 5MHz, 1MHz and decade selectable 100kHz >down to 1Hz. All rising edges synchronised to the 10MHz clock rising edge >(or as near as I can get with 74AC logic). With a considerable amount of >constructive criticism from Bruce Griffiths (thank you again Bruce) I >believe the design now to be complete. > >The aim is to have as low a level of nasties as possible (i.e. fit for >time-nuts). > >All faults are my own - no blame attaches to Bruce! > >I've not yet subjected this design to the ultimate simulation tool (PCB, >parts and solder) yet, and I have no means to test it for levels of jitter >(phase noise) or similar nasties. > >I think that it's now the right time to open the design up for critique from >a wider audience before I commit it to copper. > >I'm therefore attaching the design as a PDF file for your comments. > >A few comments are in order: > >1) The 5Mhz and 1MHz outputs are re-clocked TWICE deliberately to delay them >by one clock cycle so they line up with the 1MHz and lower outputs. > >2) The selected output (at the '4051 mux) from the ripple counter chain is >re-clocked to 1MHz before re-clocking to 10MHz as the worst-case delay in >the chain of '4017s is large enough that the lower frquencies wouldn't >reliably re-clock directly to 10MHz. > >I have also done a PCB layout (4-layer) and I'm happy to send a print of the >top/bottom layers to anyone who feels that they want to comment on that >(inner layers are ground and power). > >Let the brick-bats be thrown! > >Cheers >Dave >No virus found in this outgoing message. >Checked by AVG - http://www.avg.com >Version: 8.0.138 / Virus Database: 270.4.7/1544 - Release Date: 10/07/2008 >07:37 _______________________________________________ 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.