Re: [time-nuts] Distributiuon Amlifier Altinex DA1804NT
On Thu, 28 May 2015 14:09:36 -0400, Vlad wrote: I am not sure what to blame. ;-) I'm using a TB on a 350Mhz video amplifier 6xRGB , and discovered that the Video DistAmp was clipping the 10Mhz from the TB. I used a 10dB attenuator on the TB signal (6dB would have been better) , but i had a 10dB in the drawer. Watch out for putting a too high signal into a 1V-PP Video Dist Amp. CFO Denmark ___ 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] Distributiuon Amlifier Altinex DA1804NT
Hi Vlad, Before we get to your phase noise question... Your plots ALTINEX-DA-F.png ALTINEX-DA-T.png look odd and the plot ALTINEX-DA.png shows massive amount of glitches. You must make sure that the frequency and the phase plots look nice before doing an ADEV plot. In this case there's probably something wrong with your setup. You should NOT be seeing all those jumps, spikes, wiggles, and noise in a frequency plot. Hundreds of outlier data points are destroying the validity of the ADEV calculations. Something is very wrong. Check wires, connectors, power supplies, groundings, vibration, air flow, mains voltage, etc. Try a 3rd oscillator in case it's a problem with one of your two oscillators. But you have to get rid of those spikes in the ALTINEX-DA-F.png plot. The way we usually test a distribution amp is to use a single oscillator and a splitter; one leg goes through the DA and the other does not. The phase difference plot then reveals the stability of the DA. But regardless of how you measure a DA, the frequency plot should not have so many erratic glitches. The kind of plot you should expect is the smooth portion between the 8700 second and 11600 second grid lines. /tvb - Original Message - From: Vlad t...@patoka.org To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Wednesday, May 27, 2015 7:04 PM Subject: [time-nuts] Distributiuon Amlifier Altinex DA1804NT Hello, Recently, I acquired video distribution amplifier (model Altinex DA1804NT). It says it could handle 350Mhz. I am planing to use it to split 10Mhz Ref signal from my OCXO. This OCXO I bought on auction site. It has Oscilloquarz model 8663-SX plus some components which give me 4 outputs - 2 sines and two squares. After few days of warm up I did measurement of ADV from one of the sine outputs and then measurement of the same sine signal from OCXO, but this time through the Altinex DA. Each test took 8 hours. Attached is the results. NOTE: on the ALTINEX* charts I forgot to change the label for OCXO. So, its not DATUM. It is Oscilloquarz 8663-SX I was using Trimble TB as a ref signal for HP 5386 Since I have no instruments which measuring phase noise, I am interesting, what will be the quick method to measure the phase noise for that DA ? -- WBW, V.P. ___ 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] Distributiuon Amlifier Altinex DA1804NT
Tom, I agree that spikes looks weird. Looking for the raw data, I see its fluctuate from 9.99958E+6 to 1.49E+7 And here how its spread: #occurr. / FREQ 1 +9.99958E+6 1 +9.99980E+6 1 +9.99981E+6 1 +9.99988E+6 1 +9.99989E+6 1 +9.0E+6 1 +9.2E+6 1 +9.6E+6 1 +9.9E+6 2 +1.01E+7 1 +1.04E+7 1 +1.05E+7 3 +1.06E+7 2 +1.07E+7 4 +1.08E+7 4 +1.10E+7 4 +1.11E+7 7 +1.12E+7 1 +1.13E+7 17 +1.14E+7 12 +1.15E+7 37 +1.16E+7 394 +1.17E+7 1772 +1.18E+7 1362 +1.19E+7 550 +1.20E+7 120 +1.21E+7 73 +1.22E+7 34 +1.23E+7 12 +1.24E+7 8 +1.25E+7 6 +1.26E+7 5 +1.27E+7 1 +1.28E+7 3 +1.30E+7 2 +1.31E+7 2 +1.32E+7 1 +1.33E+7 1 +1.49E+7 I am not sure what to blame. ;-) The setup is pretty simple (on my taste). Its Trimble TB, connected to linear power supply. The GPS antenna connected via HP GPS Distribution amplifier and mounted permanently. The 10 Mhz output from that Trimble TB, connected by coax. cable to Ref input of HP 5386A. The OCXO connected to the input A of counter by very short coax. cable. I was using diffrent PSU for all OCXO. Its switching PSU from IBM LapTop, its HP laboratory PSU (Linear, 0-24V) and its XL125 switching Power Supply. I tried following OCXO: MV89A, its Oscilloquarz 8663-SX and its DATUM OCXO (not remember its model. It looks exactly the same as one in use inside of Trimble TB). And all of them shows spikes. Today, I'll try to use one of those OCXO as Ref signal for counter and try to measure another OCXO using that ref. That will give me some clue if Trimble TB has an issue. Regards, Vlad On 2015-05-28 03:32, Tom Van Baak wrote: Hi Vlad, Before we get to your phase noise question... Your plots ALTINEX-DA-F.png ALTINEX-DA-T.png look odd and the plot ALTINEX-DA.png shows massive amount of glitches. You must make sure that the frequency and the phase plots look nice before doing an ADEV plot. In this case there's probably something wrong with your setup. You should NOT be seeing all those jumps, spikes, wiggles, and noise in a frequency plot. Hundreds of outlier data points are destroying the validity of the ADEV calculations. Something is very wrong. Check wires, connectors, power supplies, groundings, vibration, air flow, mains voltage, etc. Try a 3rd oscillator in case it's a problem with one of your two oscillators. But you have to get rid of those spikes in the ALTINEX-DA-F.png plot. The way we usually test a distribution amp is to use a single oscillator and a splitter; one leg goes through the DA and the other does not. The phase difference plot then reveals the stability of the DA. But regardless of how you measure a DA, the frequency plot should not have so many erratic glitches. The kind of plot you should expect is the smooth portion between the 8700 second and 11600 second grid lines. /tvb - Original Message - From: Vlad t...@patoka.org To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Wednesday, May 27, 2015 7:04 PM Subject: [time-nuts] Distributiuon Amlifier Altinex DA1804NT Hello, Recently, I acquired video distribution amplifier (model Altinex DA1804NT). It says it could handle 350Mhz. I am planing to use it to split 10Mhz Ref signal from my OCXO. This OCXO I bought on auction site. It has Oscilloquarz model 8663-SX plus some components which give me 4 outputs - 2 sines and two squares. After few days of warm up I did measurement of ADV from one of the sine outputs and then measurement of the same sine signal from OCXO, but this time through the Altinex DA. Each test took 8 hours. Attached is the results. NOTE: on the ALTINEX* charts I forgot to change the label for OCXO. So, its not DATUM. It is Oscilloquarz 8663-SX I was using Trimble TB as a ref signal for HP 5386 Since I have no instruments which measuring phase noise, I am interesting, what will be the quick method to measure the phase noise for that DA ? -- WBW, V.P. ___ 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. -- WBW, V.P. ___ 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] Distributiuon Amlifier Altinex DA1804NT
I know some manufacturers use pot core transformers on the output signal. HP does it for sure. Any vibration or shock transforms right into the phase error of the signal. IMO, those distribution amps should be avoided as any level of shock or vibration will contribute to jitter. On Thu, May 28, 2015 at 3:28 PM, cfo xne...@luna.dyndns.dk wrote: On Thu, 28 May 2015 14:09:36 -0400, Vlad wrote: I am not sure what to blame. ;-) I'm using a TB on a 350Mhz video amplifier 6xRGB , and discovered that the Video DistAmp was clipping the 10Mhz from the TB. I used a 10dB attenuator on the TB signal (6dB would have been better) , but i had a 10dB in the drawer. Watch out for putting a too high signal into a 1V-PP Video Dist Amp. CFO Denmark ___ 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.
[time-nuts] Indoor positioning
From time to time this subject rises again, so i´m sending these links: http://www.electronics-eetimes.com/en/kickstarter-project-offers-indoor-positioning-on-arduino.html?cmp_id=7news_id=222924926vID=209 http://analog-eetimes.com/en/cmos-chip-enables-real-time-location-with-a-precision-of--10cm.html?cmp_id=7news_id=222905929 Daniel ___ 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.
