[time-nuts] Phase noise measurement experiment by Andrew Holme

the differences between 14 bits and 16 bits ADC are. Regards Li Ang / BI7LNQ ___ 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.

Re: [time-nuts] PRS10 PRBB Shematics

Hi Guys I have just bought 2 kinds of PRS10 connectors on taobao.com. (PCB type and cable type, refer to the attached photo). It is about 8$ each(the D-SUB + center RF part). If you are looking for it, I can send you the link off the list. Yours Li Ang / BI7LNQ

Re: [time-nuts] SR620/PM66xx/CNT-90 input stages

Hi I think the purpose is to get high input impedance for high frequency signal. The input impedance of comparator is high at low frequency range only. Li Ang / BI7LNQ ---Original--- From: "Attila Kinali"<att...@kinali.ch> Date: 2017/6/20 15:20:44 To: "Discussion of preci

Re: [time-nuts] First batch data of China pulstar observation satellite

observation satellite XPNAV-1. 5. detector intro: wolter-i focused x-ray detector. energy range: 0.5-10keV. view : 2ω=15'. geometric area: 30cm2@1.5keV. Time resolution:<=1.5us. Energy resolution: <=180eV@5.9keV. -- Original -- From: "Li Ang"

[time-nuts] First batch data of China pulstar observation satellite

and related information. Regards Li Ang / BI7LNQ ___ 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.

Re: [time-nuts] How to create a super Rb standard

Hi I am wondering if anyone tried to put a Rb unit into a vacuum container. And how much the performance is improved? Someone told me that's why the Rb clocks are more stable than Cs clocks on the GPS satellites. LiAng ---Original--- From: "Bob Camp" Date: 2017/1/17 21:20:23 To:

Re: [time-nuts] Performance of TDC7200

Hi Thanks for the info. The fpga baesed TDC is something I am interested in. However, I am a beginner of fpga programming. Maybe next year I will spend sometime study this project. VHDL is quite difficult for a C programmer :(. Regards Li Ang BI7LNQ ---Original--- From: "Attila Kinali

[time-nuts] Performance of TDC7200

a/20161209/freqcnt_v6_20161209_3corneredhat.png TODO list: 1) web based interface, calculate and show *DEVs with javascript on Chrome browser 2) front end experiments Regards Li Ang / BI7LNQ ___ time-nuts mailing list -- time-nuts@febo.com To unsub

Re: [time-nuts] New Timestamping / Time Interval Counter: the TICC

Great job. I am doing a similar project too. I've just sent gerber/pos/bom files to the PCB company. 3 tdc7200s are used on my board to support the 3-corner-hat measurement. Regards Li Ang ---Original--- From: "John Ackermann N8UR"<j...@febo.com> Date: 2016/11/25 22:57:33

Re: [time-nuts] 5071A with ATTENTION flashing

oscillators. I also told him to keep the leaky one running for days and see what's going on. If it goes to normal, price will x2 or more. regards Li Ang ---Original--- From: "Tom Van Baak"<t...@leapsecond.com> Date: 2016/11/13 19:34:59 To: "Discussion of preci

Re: [time-nuts] 5071A with ATTENTION flashing

HI I just came back from another 5071a seller. #1-#3 fatal error: max emult. #4 fatal error: overcureent (about 80uA) I put the tube from #1 to #4. #4 became a "max emult" one. I think the tube #1 is really dead and the circuit of #4 is functional. Since the ion pump current was dropping

Re: [time-nuts] 5071A with ATTENTION flashing

ges of a DDS-based GPSDO instead of the traditional DAC/EFC method. /tvb - Original Message - From: Li Ang To: Tom Van Baak ; Discussion of precise time and frequency measurement Sent: Tuesday, November 08, 2016 10:48 PM Subject: Re: [time-nuts] 5071A with ATTENTION flashing Hi Tom I have

Re: [time-nuts] 5071A with ATTENTION flashing

According to the Log, "CBT Oven Err: -9.55 C" might be something wrong. However, I can't find the correct range in the manual. Does anyone have the information about this parameter? Regards Li Ang -- Original -- From: "Li Ang";<379

Re: [time-nuts] 5071A with ATTENTION flashing

Hi Tom I have collected the log from it. Log level is service. The 9.2G pll pass the test today. The log during the power-up process is also included. Regards Li Ang / BI7LNQ - scpi > MJD0 02:02:18 CBT ID: 3128A00642(H) Status summary: Fa

Re: [time-nuts] 5071A with ATTENTION flashing

Hi Tom Thanks for the info. I think I should pay a visit to this 5071a again. There are 5 more 5071a 200km away, I need to visit them next week. :) regards Li Ang / BI7LNQ ---Original--- From: "Tom Van Baak"<t...@leapsecond.com> Date: 2016/11/4 00:42:46 To: "Discu

Re: [time-nuts] Time nut soon to be in Shenzhen

Hi Welcome to Shenzhen. As far as I know there is no market that you can see pile of OCXO. They were taken off from equipments, and the process is done in the Qingyuan or Shanwei city Guangdong province. The seller might be in Shenzhen, but the source is in Qingyuan/Shanwei. These city have

[time-nuts] 5071A with ATTENTION flashing

Hi Today I met one HP 5071A with option 001 at one secondhand equipment company. This one can not enter CONTINUOUS OPERATION status, the ATTENTION led flashes. There is a "Low cs signal with max Emult" error in the log. I have run the self-test, and it stopped at "9.2GHz PLL test 10.3v". I

[time-nuts] TDC-GP22 vs TDC7200

Hi I got 5 samples of TDC7200 from TI a few months ago. I have made a board to test it with TDC-GP22 from ACAM. Actually it's a new board of my frequency counter. The CPU system is changed from MCU to a OrangePi board. The digital part is still a Cyclone 4 FPGA. Verilog:

Re: [time-nuts] DMTD - analog multiplier vs. diode mixer ?

Hi Thanks to all the information here. I can put more items to my experiment list. Regads Li Ang, BI7LNQ 2016-01-11 11:28 GMT+08:00 Magnus Danielson <mag...@rubidium.dyndns.org>: > Moin, > > On 01/10/2016 07:56 PM, Attila Kinali wrote: > >> On Sun, 10 Jan 2016

Re: [time-nuts] DMTD - analog multiplier vs. diode mixer ?

Hi Bob, In some article, I see people use a D-flipflop to sample the input signal with reference clock. When you want implement a mixer what's the difference between D-flipflop and XOR gate? Acorrding to my understanding, to multiply 1bit with another, I should use an AND gate, right? When

Re: [time-nuts] homebrew counter new board test result

, it might vary few ms. 2) Does any one have the test data of 12 digit/s counter when DUT=REF? I want to know the gap between mine and a commercial counter. Thanks Li Ang 2015-02-27 4:30 GMT+08:00 Charles Steinmetz csteinm...@yandex.com: Magnus wrote: A bit of hysteresis can help to avoid

Re: [time-nuts] homebrew counter new board test result

will evaluate with it. 2015-02-25 0:02 GMT+08:00 Attila Kinali att...@kinali.ch: On Tue, 24 Feb 2015 14:43:10 +0800 Li Ang lll...@gmail.com wrote: I saw people talking about using 74AC to square the signal, what's the difference between 74LVC and 74AC? 74AC is not easy to get

Re: [time-nuts] homebrew counter new board test result

talking about using 74AC to square the signal, what's the difference between 74LVC and 74AC? 74AC is not easy to get. Thanks Li Ang 2015-02-24 5:36 GMT+08:00 Magnus Danielson mag...@rubidium.dyndns.org: Dear Li Ang, Nice to have you back reporting on your progress! Now, you have some pretty

[time-nuts] homebrew counter new board test result

Hi, I'm back. I have been testing my new borad for days. Compared to previous version, this board makes the PCB track of signals far from each other and replaces LDO for TDC with LP5907. CH_A: simple resistor bias and ac couple front end, CH_B: CH_A+MC100LVELT22 LVPECL , CH_C:

Re: [time-nuts] New algorithm, better ADEV

Li Ang ___ 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.

Re: [time-nuts] L1 and L2 frequencies

Hi I have a question about the GPS antenna. Since the GPS signal strength on the ground is about 20db lower than the thermal noise, does the gain of antenna matter? 2015-01-16 7:01 GMT+08:00 Björn Gabrielsson b...@lysator.liu.se: Magnus, If civilian receivers where to implement L2C and L5

Re: [time-nuts] New algorithm, better ADEV

Magnus Danielson magnus@... writes: Which display is it? Hi Mangus, I do not know the model name, but I found the same one on ebay (key word 2.2 TFT SPI). It's a SPI screen, so it shows things quite slow. However, 320x240 resolution is good to display a lot of slow changing stuffs. I use

Re: [time-nuts] New algorithm, better ADEV

Tom Van Baak tvb@... writes: Just use: ref_delta = ref_curr - ref_prev; sig_delta = sig_curr - sig_prev; Not only is it much simpler but it also works in every case (your code would fail whenever curr equals prev). Here's a test program in case you don't believe me:

[time-nuts] New algorithm, better ADEV

Hi Just now, I changed the way to calculate frequency and get a better ADEV chart. http://www.qsl.net/b/bi7lnq/freqcntv4/test/20150114/0114.gif http://www.qsl.net/b/bi7lnq/freqcntv4/test/20150114/newway.tim http://www.qsl.net/b/bi7lnq/freqcntv4/test/20150114/oldway.tim Thanks to John

Re: [time-nuts] schematics of frequency counter

is there now. There is something need to figure out. Thanks Li Ang ___ 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.

Re: [time-nuts] schematics of frequency counter

= 0x, Register_4 = 0x2000, Register_5 = 0 27, Register_6 = 1 12; 2015-01-06 7:33 GMT+08:00 Li Ang lll...@gmail.com: Hi Bob, There are 2 oscillator on board, one 8MHz for MCU one 125MHz for FPGA. I've took it down from the board, and changed MCU to use internal RC oscillator

Re: [time-nuts] schematics of frequency counter

Hi Neil Just now, I disconnected TPS79333 from board and used LR6 battery for the analog part of TDC. The result does not show improvement. So I think LDO might not be the primary noise contributor. Thanks for the suggestion. 2015-01-03 22:01 GMT+08:00 Neil Schroeder gign...@gmail.com: I

Re: [time-nuts] schematics of frequency counter

need new board to verify. I have got some BFT92 and looking for pin-pin compatible low noise LDO to play with. Thanks Li Ang ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time

Re: [time-nuts] schematics of frequency counter

Hi Magnus You are right, I could compensate it in the software. I've tried that. The software sets sig=ref=10MHz and measures start-to-stop time t1. Then, it sets sig=ref=5MHz and measures time t2. With t1 t2, I could get the time difference between the start path and the stop path. Repeat it

Re: [time-nuts] schematics of frequency counter

Hi Bob, Actually, I dont want to ask my colledge for help. Everytime ,for each guy I ask for help, I need expain the entire system and principle of a frequency counter to him. They just keep asking questions instead of answering mine. :( The 2 MV89As are powered by the same power supply

Re: [time-nuts] schematics of frequency counter

4:35 GMT+08:00 Bob Camp kb...@n1k.org: Hi On Dec 28, 2014, at 9:19 AM, Li Ang lll...@gmail.com wrote: Hi Bob, I did some test according to your suggestions. DUT is a symmetricom x72 rb oscillator. Also, I've tried signal generator as the DUT. RS SMY01 is not as good as HP8662A

Re: [time-nuts] schematics of frequency counter

kb...@n1k.org: Hi On Dec 28, 2014, at 9:19 AM, Li Ang lll...@gmail.com wrote: Hi Bob, I did some test according to your suggestions. DUT is a symmetricom x72 rb oscillator. Also, I've tried signal generator as the DUT. RS SMY01 is not as good as HP8662A but that the best I've got

Re: [time-nuts] schematics of frequency counter

compensation network. Its a fabulous part for a sensitive application like yours. I'm hoping I am right in assuming that the noise performance of the LDOs is a concern, and don't mean to even dare suggest that you've done anything but a great job! :-) NS On Sat, Dec 27, 2014 at 5:34 AM, Li Ang lll

Re: [time-nuts] schematics of frequency counter

. But to assist you further, please find a spread-sheet of it attached. Notice that I scaled the values by 100 ns before further processing. Cheers, Magnus On 12/31/2014 01:03 PM, Li Ang wrote: Hi Magnus, I'm not familar with error analysis and statistics, can you tell me how to calculate

Re: [time-nuts] schematics of frequency counter

, Magnus On 12/29/2014 01:55 PM, Li Ang wrote: Hi Magnus, The unit of these data is not ns but reference clock cycles (100ns). TDC_GP22 measures the time between the edge of tdc_start and tdc_stop1, then it measures the reference clock automaticly. The result you get from it is the ratio

Re: [time-nuts] New GPSDO on EBAY From China

. They have a nice looking unit, but are still trying to figure out the bugs and finish up the software … Bob On Dec 28, 2014, at 6:19 PM, Li Ang lll...@gmail.com wrote: Hi This unit is done by BG7TBL. In his store on taobao.com, there is a adev chart. Please refrer to this link http

Re: [time-nuts] schematics of frequency counter

2,243 ps RMS jitter, which isn't all that bad. Yes, it will spread out to that 11 ps peak-to-peak jitter, but it is to be expected. It's pretty respectable for a home-built. Cheers, Magnus On 12/28/2014 03:19 PM, Li Ang wrote: Hi Bob, I did some test according to your suggestions

Re: [time-nuts] New GPSDO on EBAY From China

Hi This unit is done by BG7TBL. In his store on taobao.com, there is a adev chart. Please refrer to this link http://item.taobao.com/item.htm?spm=a1z10.3.w4002-1278071728.49.XHJlQLid=42336500072 2014-12-29 1:56 GMT+08:00 Dan Rae dan...@verizon.net: On 12/28/2014 7:25 AM, David Smith

Re: [time-nuts] schematics of frequency counter

. Once that is done, build the input channel(s) on their own board(s). They will need their own regulators to keep noise down (regulators are cheap). You can optimize the input channel circuits as part of a separate project. Bob On Dec 26, 2014, at 8:21 AM, Li Ang lll...@gmail.com wrote

Re: [time-nuts] schematics of frequency counter

Hi Charles, In my circuit, the VCC is 5v. I've noticed my bias and emitter resistor is something need to be changed. I will play with the resistors and see if it improves. Thanks. 2014-12-27 6:42 GMT+08:00 Charles Steinmetz csteinm...@yandex.com: Li Ang wrote: RF pnp transistor is harder

Re: [time-nuts] schematics of frequency counter

). They will need their own regulators to keep noise down (regulators are cheap). You can optimize the input channel circuits as part of a separate project. Bob On Dec 26, 2014, at 8:21 AM, Li Ang lll...@gmail.com wrote: Hi Thanks for the suggestion. I will do some experiments with the front

Re: [time-nuts] schematics of frequency counter

* of different ways to do the same sort of thing. I would not go overboard doing this with complicated circuits. You simply want a way to figure out what the input circuits are doing. Have Fun! Bob On Dec 24, 2014, at 11:19 AM, Li Ang lll...@gmail.com wrote: http://www.qsl.net/bi7lnq

Re: [time-nuts] schematics of frequency counter

GMT+08:00 Charles Steinmetz csteinm...@yandex.com: In reply to Li Ang, Bruce wrote: The CLK1 input circuit produces an output incompatible with the 3.3V CMOS device it drives.A pair of pnp transistors in an otherwise similar circuit is capable of producing a 3.3V CMOS compatible output

[time-nuts] schematics of frequency counter

http://www.qsl.net/bi7lnq/freqcnt_bi7lnq_v4.pdf this is my current board. I'm not a hardware guy, feel free to correct my mistakes. :) http://assets.fluke.com/manuals/6690smeng.pdf schematic of cnt90 aka pm6690 Happy holidays Li Ang

[time-nuts] Homebrew frequency counter, new board test result

to ground test instruments 1) HP6622A as power supply 2) FE5650 rb as reference 3) PRS10 rb as DUT Li Ang ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow

Re: [time-nuts] Homebrew frequency counter, need help

___ 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.

Re: [time-nuts] Fw: Homebrew frequency counter, need help

Thanks Tom, The front end is still 75ALS176, but I put another simple transistor circuit from wenzel to to compare the performance. http://www.wenzel.com/wp-content/uploads/diffsqr.gif 2014-12-12 17:04 GMT+08:00, Tom Van Baak t...@leapsecond.com: This large posting is from Li Ang. /tvb

Re: [time-nuts] Homebrew frequency counter, need help

= 0; } } 2014-12-12 21:18 GMT+08:00 Bob Camp kb...@n1k.org: HI On Dec 12, 2014, at 4:04 AM, Tom Van Baak t...@leapsecond.com wrote: This large posting is from Li Ang. /tvb - Original Message - From: Li Ang To: Discussion of precise time and frequency measurement

Re: [time-nuts] Homebrew frequency counter, need help

independent sources (one reference and the other as input)? I’m guessing that the answer is yes in both cases. Bob On Dec 12, 2014, at 10:40 AM, Li Ang lll...@gmail.com wrote: Hi Bob, The job done by linear regression is to reduce the uncertainty. This counter is designed to use

Re: [time-nuts] Homebrew frequency counter, need help

-stop1= -6 stop1-start= 2013, stop2-stop1= -6 stop1-start= 2016, stop2-stop1= -2 stop1-start= 1987, stop2-stop1= -2 stop1-start= 2062, stop2-stop1= -6 stop1-start= 2021, stop2-stop1= -5 2014-11-29 1:41 GMT+08:00 Bob Camp kb...@n1k.org: Hi On Nov 28, 2014, at 10:14 AM, Li Ang lll

Re: [time-nuts] Homebrew frequency counter, need help

Hi Thanks for the great article. I did a little test just now. To measure the refclk of itself. And this is the result(I kept 10 digits of the fraction part): ### Frequency Counter startup ### gate=1s #=8985 freq=10.02 gate=1s #=9038 freq=10.01 gate=1s #=9039

Re: [time-nuts] Homebrew frequency counter, need help

I did a little calculation and it's a 10 digits counter. log(10,000,000,005) = 10. There is still a big gap between this one and 53132A :( For 53132A, the time resolution is 150ps, which I think is 10digits/s with interpolator. According to the schematics the only difference between 53132A

Re: [time-nuts] Homebrew frequency counter, need help

1) What frequency is the crystal at? (can you drive the chip from an OCXO?) I'm clking this chip with the refclk/2=5Mhz, which is done by cpld. something like always @(posedge refclk) tdc_clk = ~tdc_clk; Not sure if it's noisy. 2) Is there more bypassing on the circuit than shown? (If not, add