); SAEximRunCond expanded to false Errors-To: [EMAIL PROTECTED] RETRY jan seems to be having a bit of trouble posting so I'll add his off list reply to the list discussion. I too have one of these on it's way and look forward to building it.
Eric Hi, Eric. I saw the discussions on the TimeNuts list but haven't figured out how to respond to the list so I'm emailing you directly. The DAC used on the clock has indeed a fairly high output impedance which makes the outputs sensitive to noise. This is minimized by a careful layout and a ground plane around the traces. The other result is that there are visible vector retrace lines (when the beam jumps from one location to another) if there is a significant capacitance on the outputs. This effect is minimal when using 10X probes. There is a suggested hardware modification using 2 load resistors in the FAQ that will significantly reduce the output impedance (thus the capacitance sensitivity) and also will reduce the voltage swing, which will reduce non-linearities. Take a look at: http://www.dutchtronix.com/ScopeClock2-6faq.htm#LoadResistors Your clock kit is on the way -Jan- On 8/2/07, Robert Atkinson <[EMAIL PROTECTED]> wrote: > > ); SAEximRunCond expanded to false > Errors-To: [EMAIL PROTECTED] RETRY > > Hi Nigel & Eric, > I've just order one of Jan's clocks. He has just got PCB's back in > stock. I looked quite carefully and 1PPS is standard. The board has a > PCF8563 RTC chip with a 1PPS output that is used by the microprocessor. > The signal line has a 2 pin header that has a jumper for internal 1PPS > or you can use the header to supply an external 1PPS. > The clock has two basic modes of operation, one where the microprocessor > just reads the RTC and displays that time, the other (AVR Master Clock) > where it counts the 1PPS. While in master mode it updates the RTC to use > for reversion in case of power fail (The RTC has battery back-up on the > board). > It looks like a great little board. The only limitation I can see is > that the ADC's are un-buffered R/2R ladder types with fairly high output > impedance. I want to drive a small X-Y display so I think I will have to > build a buffer amplifier. > I'll keep the group up dated. > > Robert G8RPI. > > -----Original Message----- > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On > Behalf Of [EMAIL PROTECTED] > Sent: 31 July 2007 23:32 > To: time-nuts@febo.com > Subject: Re: [time-nuts] Scope Clock > > ); SAEximRunCond expanded to false > Errors-To: [EMAIL PROTECTED] RETRY > > > In a message dated 31/07/2007 23:23:38 GMT Daylight Time, > [EMAIL PROTECTED] writes: > > as ordered will these boards accept 1pps or was yours a special? > > Eric > kg6kqt > > > ----------- > Hi Eric > > Take a look at..... > > _http://www.dutchtronix.com/ScopeClock.htm_ > (http://www.dutchtronix.com/ScopeClock.htm) > > It looks like the 1PPS is standard. > > I've got a 12 inch X-Y display doing nothing right now...... > and I'm very tempted to have a play with one of these:-) > > regards > > Nigel > GM8PZR > > > > > _______________________________________________ > 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. > > > -------------------------------------------------------- > > > > > Genetix Limited - Queensway, New Milton, Hampshire, BH25 5NN Registered > in England No. 2660050 www.genetix.com > Any opinions expressed in this email are those of the individual and not > necessarily Genetix Ltd (Genetix) or any company associated with it. This > email and any files transmitted with it are confidential and solely for the > use of the intended recipient. If you are not the intended recipient or the > person responsible for delivering to the intended recipient, be advised that > you have received this email in error and that any use is strictly > prohibited. If you have received this email in error please notify Genetix > by telephone on +44 (0)1425 624600. > The unauthorised use, disclosure, copying or alteration of this message is > strictly forbidden. This mail and any attachments have been scanned for > viruses prior to leaving Genetix network. Genetix will not be liable for > direct, special, indirect or consequential damages as a result of any virus > being passed on, or arising from alteration of the contents of this message > by a third party. > -------------------------------------------------------- > > _______________________________________________ > 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.