Re: [time-nuts] Enhancing the TIC232 code for better data

I have posted a detailed operation of the TIC to help clear up most of the questions you asked. As far as overflow tests, a 16 MHz XO over a full second would not completely fill a 24-bit register (16777216) and 256 times that will not completely fill a 32-bit register so no overflow test is

Re: [time-nuts] How do I know my GPS stabilized oscillatorisworking?

Hi Said, first i suggest you download the tool again because a lot of changes (improvements?) have been made in the last days. * It would be good to have the tool normalize the vertical axix for every column when showing more than one column superimposed. It does this if you only view

Re: [time-nuts] Enhancing the TIC232 code for better data

Hi Richard, Thanks a lot for the very detailed explanations. I was not sure after looking at the PIC assembly code. I have never used PICs and even with my favorite micros (6805 and now 8051) I try to stay away from assembly, it's not as much fun as it used to be, now that I am used to C, even

Re: [time-nuts] Enhancing the TIC232 code for better data

Second thoughts about inverting the UTC 1PPS. I have read in a previous post that for most GPS receivers, only the leading edge of the 1PPS pulse is tightly controlled (and intended to be synchronous with the satellite signal), the falling edge is not. If this is true, we want to make sure we

Re: [time-nuts] Enhancing the TIC232 code for better data

Didier Juges wrote: Second thoughts about inverting the UTC 1PPS. I have read in a previous post that for most GPS receivers, only the leading edge of the 1PPS pulse is tightly controlled (and intended to be synchronous with the satellite signal), the falling edge is not. If this is true, we

Re: [time-nuts] Enhancing the TIC232 code for better data

Hi Bill Didier: I think that Richard is using the tvb divider on his 10 MHz reference to get to 1 PPS and that has a square wave output. Have Fun, Brooke Clarke -- w/Java http://www.PRC68.com w/o Java http://www.pacificsites.com/~brooke/PRC68COM.shtml http://www.precisionclock.com Bill

Re: [time-nuts] TIC232 Detailed Operation

I've never programmed a PIC, nor do I know much about TI measurements. But, if you wanted 100 ps resolution, would it make sense to average five 125 samples? thanks, glenn Richard H McCorkle wrote: By selecting a known sample time for the XO speed used, the LSB of the displayed data has a

Re: [time-nuts] Enhancing the TIC232 code for better data

Didier Juges wrote: Second thoughts about inverting the UTC 1PPS. I have read in a previous post that for most GPS receivers, only the leading edge of the 1PPS pulse is tightly controlled (and intended to be synchronous with the satellite signal), the falling edge is not. If this is true, we

Re: [time-nuts] How do I know my GPS stabilized oscillatorisworking?

Hello Ulrich, thanks much for your detailed response! I will need to take time to read it. There is one more issue I ran into on the older version (will get the new one now): I have integer numbers in some of my data captures, and the unit only reads in data that has a decimal point (such

Re: [time-nuts] How do I know my GPS stabilized oscillatorisworking?

Said, this a has been an issue with an intermediate version. The next version will definitely read in integer values. Regards Ulrich Bangert -Ursprüngliche Nachricht- Von: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Im Auftrag von [EMAIL PROTECTED] Gesendet: Sonntag, 13. August

Re: [time-nuts] Relationship of relative stability between distant locations using GPS and environmental factors

Way back on June 30th, Stephan asked: A number of recent entries to this list have mentioned topics relating to GPS timing and environmental corrupting factors (e.g. Ionosphere, Temp., Humidity, etc.). Personally, I am very interested in setting up a very precise relative time between

Re: [time-nuts] Enhancing the TIC232 code for better data

The inversion or delay should be introduced in the device under test 1PPS and NOT the GPS 1PPS as most GPS receivers output leading edge on time pulses that can have varying pulse widths, so inverting the GPS pulse is not a good idea. As long as there is 1us of difference between the pulses the

Re: [time-nuts] Enhancing the TIC232 code for better data

I am indeed using a TVB style divider for my DUT 1PPS and since it has a square wave 1Hz output, I programmed an inverted 1Hz output for my TIC test box DUT 1Hz. That way any drift over time keeps the phase detector and TIC well away from the zero crossing during long-term testing. I remove the

Re: [time-nuts] Enhancing the TIC232 code for better data

The reason the Fairchild HC4046 doesn't work is it doesn't have a S/R F/F output on pin 15 and the other devices do. What I found in testing the different HC4046's with an MTI-260 (very low phase noise oscillator) GPSDO controller I designed was the Phillips part introduced the least phase

Re: [time-nuts] TIC232 Detailed Operation

The key is the total number of samples added together. Adding together 5 groups of 125 measurements each works as well as taking 625 measurements and gives 100ps LSB resolution. Averaging 5 groups of 125 measurements is the same as 125 measurements and gives an average with 0.5ns LSB resolution