Ah! Sounds like you were subjected to the "Bruce factor". It's a case of publish a design and then expect to be insulted about it. I'm glad you weathered the storm and wish to thank you for your present.
Steve On 26 June 2010 19:11, Richard H McCorkle <mccor...@ptialaska.net> wrote: > Fellow Time-Nuts, > When I first uploaded the Simple PICTIC interpolating time interval > counter to the K04BB site in 12/08 and presented it to the group as > a Christmas present my goal was to get amateurs building their own > interpolating time interval counters for GPS monitoring and making > improvements to my design. The interpolator in the PICTIC was > “borrowed” from an early HP counter with minor modifications so I > didn’t design it and had no personal attachment to it. My forte is > writing PIC assembly code for time and frequency applications and > I make no claims of being a hardware design engineer. I am just > an amateur interested in writing PIC code and was building my own > PICTIC. I wanted to share my design, as I couldn’t afford multiple > commercial high-resolution time interval counters to monitor my > standards and thought there might be others with similar needs that > could benefit from a low cost TIC design. > Testing the HP interpolator with my code showed it had sufficient > capability to be useful in a low cost TIC for GPS monitoring where > a modest resolution increase was desired. In response to my posting > I was subjected to a barrage on the shortcomings of the interpolator > with few comments on the rest of the design. I responded to the > comments based on test results showing it was sufficient for purpose > and suggested trying the design before saying it wasn’t usable. The > response returned was “I wouldn't waste my time with a circuit that > is inherently as non-linear as yours.” so the rest of the design was > discounted by others as not being worth the time to evaluate. I began > a discussion on line about the interpolator, which was destined to > turn into a long and annoying thread similar to the recent TPLL > discussion. Rather than getting into it on line I elected to put a > stop to it by saying publicly I was at fault and would begin further > study, as I am not as thick skinned as Warren. Subsequent independent > testing of the PICTIC by William Riley showed the interpolators were > linear to the 10-bit ADC resolution over the measurement range with > suitable accuracy for the intended application of GPS monitoring > as originally stated. > Over the last 18 months I have developed a new diode switched > interpolator based on the comments made on line and have thoroughly > tested it. Some suggestions made improvements in the performance and > some resulted in poorer performance. I incorporated those suggestions > that made improvements, eliminated those that made things worse, and > once I was satisfied I sent the revised interpolator design directly > to Bruce off line. Based on comments and suggestions he returned > during a long series of emails I incorporated additional changes in > the code, front-end, and interpolator designs and tested those > changes until I was satisfied with the performance and he had no > further comments. I am finally satisfied with the new design and > admit that by incorporating the majority of the suggestions made > the new interpolator has significantly better linearity than the > HP interpolator used in the PICTIC and it is now suitable for > higher resolutions. > I was reluctant to post the PICTIC II in this forum, as I don’t > want to get in another public discussion of its faults without any > discussion of the merits of a $50 serial output interpolating TIC > on a 3.8” x 2.5” thru-hole board designed for amateur construction. > The K04BB WIKI PICTIC page was recently updated to include the > PICTIC II code and ExpressPCB board layout and schematic files for > those that might be interested. > > http://www.ko4bb.com/dokuwiki/doku.php?id=precision_timing:pictic > > The PICTIC II incorporates the new interpolator, requires a delay > between the inputs, and uses a low stability XO timebase with > software peak detection for calibration with provision for an > external timebase like the PICTIC to minimize size and cost. > > Richard > > > > > _______________________________________________ > 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. > -- Steve Rooke - ZL3TUV & G8KVD The only reason for time is so that everything doesn't happen at once. - Einstein _______________________________________________ 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.