In my best "HAL 9000" voice; Hi Dave. Dave, what are you doing ? Dave we need BNC connectors. Those SMB's are hard to work with. Dave, are you intending to have those SMB's stick out through a panel ? Dave ? Dave, let me suggest that you layout the connector pattern so either one can be used and stick out a panel.
Dave ? Dave ? Why are you unplugging my internet feeeeeee-------- Bill....WB6BNQ "David C. Partridge" wrote: > 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 > > ------------------------------------------------------------------------ > Name: Frequency Divider 2.pdf > Frequency Divider 2.pdf Type: Portable Document Format (application/pdf) > Encoding: base64 > > ------------------------------------------------------------------------ > _______________________________________________ > 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.
