[time-nuts] Lucent KS-24361 / Z3810A : Strange behavior without GPS reception
Hi, received my Lucent KS-24361 combo, linked both units, powered them up. They tracked 8 satellites with an outdoor antenna... all fine. Repowered both units, but now using an indoor GPS antenna with bad reception. REF1 is in Locked to Ext: stabilizing frequency mode with TFOM=3, FFOM=1 and 1PPS TI +40.0 ns relative to Ext, but it is in StandBy. REF0 is ON and in Power-up: GPS acquisition mode with TFOM=9, FFOM=3. Why isn't REF1 providing the 15Mhz/1PPS signal? Here the status windows: --- Primary Receiver Status --- SYNCHRONIZATION ... [ Outputs Invalid ] SmartClock Mode ___ Reference Outputs ___ Locked TFOM 9 FFOM 3 Recovery 1PPS TI -- Holdover HOLD THR 1.000 us Power-up: GPS acquisition Holdover Uncertainty Predict -- ACQUISITION .. [ GPS 1PPS Invalid ] Tracking: 0 Not Tracking: 9 Time PRN El Az PRN El Az GPS 23:22:29 (?) 31 Jan 2015 * 1 -- --- *31 Acq GPS 1PPS Invalid: not tracking * 2 Acq ANT DLY 60 ns * 4 -- ---Position *12 Acq MODE Survey 21 17 179 Suspended: track 4 sats *25 Acq LAT N 50:34:27.066 *29 84 86LON E 6:15:59.517 *30 -- ---HGT +608.80 m (GPS) ELEV MASK 10 deg *attempting to track HEALTH MONITOR . [ OK ] Self Test: OKInt Pwr: OK Oven Pwr: OK OCXO: OK EFC: OK GPS Rcv: OK -- Secondary Receiver Status -- SYNCHRONIZATION [ Outputs Valid/Reduced Accuracy ] SmartClock Mode ___ Reference Outputs ___ Locked to Ext: stabilizing frequency TFOM 3 FFOM 1 Recovery 1PPS TI +40.0 ns relative to Ext Holdover HOLD THR 1.000 us Power-up Holdover Uncertainty Predict 432.0 us/initial 24 hrs ACQUISITION [ Ext 1PPS Valid ] Tracking: 0 Not Tracking: 9 Time _ +1 leap second pending PRN El Az PRN El Az GPS 23:24:10 (?) 31 Jan 2015 * 1 -- --- *31 59 270 GPS 1PPS Invalid: not tracking * 2 22 45ANT DLY 60 ns * 4 -- ---Position *12 17 104MODE Survey: 0% complete 21 18 179 Suspended: track 4 sats *25 56 102INIT LAT N 50:34:27.066 *29 83 80INIT LON E 6:15:59.517 *30 -- ---INIT HGT +608.80 m (GPS) ELEV MASK 10 deg *attempting to track HEALTH MONITOR . [ OK ] Self Test: OKInt Pwr: OK Oven Pwr: OK OCXO: OK EFC: OK GPS Rcv: OK Thanks, Klaus -- k...@gmx.de ___ 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] ***SPAM*** Re: 510 doubler
One issue is that to reduce flicker phase noise the 5MHz input signal output impedance should be sufficiently large to ensure that the JFET common gate input impedance is significantly smaller. ie there is significant series RF feedback in the JFET source circuit. Bruce On Sunday, 1 February 2015 2:57 PM, Charles Steinmetz csteinm...@yandex.com wrote: Andrea wrote: the square-law characteristic of devices should be avoided, so the configuration of the doubler must be some sort of ideal full wave rectifier I disagree strongly with this, at least where push-push JFET doublers are concerned. If you look at the schematic Bruce posted on his site, which uses a pair of J310 FETs driven into the pinch-off region, it runs the FETs from 0 to about 21mA. My circuit, when using J310s, runs the FETs from about 1mA to about 16mA. In both cases, when the FETs are conducting they are operating as common-source linear amplifiers, NOT as switches. In either case, when one FET is drawing low (or zero) current, the other one is drawing high current. The theoretical noise improvement due to running the low-current FET past the pinch-off point is, in practice, totally swamped by the noise from the other FET. In order to realize a useful reduction of noise, the FETs would have to switch hard, from off (beyond pinchoff) to full on (with Vgs=0) -- but JFETs don't work like that, unless you drive the gates hard with square waves (that is how commutating mixers such as the ones designed by Ed Oxner and the later H-mode mixers work). See below for a schematic of an Oxner mixer using a quad JFET (but note that commutating mixers generally use MOSFETs). When my circuit is normalized for 50 ohm output (by using a 4:1 transformer at the output -- which is the preferred method of driving 50 ohms with it) and the bias and drive are adjusted for the same currents as Bruce's circuit, the models predict almost identical noise from the two circuits. As a real-world check, I adjusted the bias conditions and drive on my breadboard doubler to give FET currents from 1 to about 22mA, and the measured noise decreased by a fraction of a dB. (The spurious distortion products rose somewhat, but not nearly as much as when one drives the FETs beyond pinch-off.) So no, running the FETs in Class AB or B does NOT confer a material noise advantage compared to running them in barely Class A, as my design does. It does, however, create an exponential explosion of odd-order distortion products that must be removed if the circuit is to be useful for time nuts purposes. So in my view, the barely Class A push-push JFET doubler is clearly superior to its Class AB or B cousin. it's better to use diode-connected transistors like the 2N * * * matching is very important, so monolithic doubles or quadruples could be the right choice, provided their other characteristics are compatible and the substrate connection is not a problem [NB: this applies to a mixer-based doubler, not a JFET push-push doubler.] Again, this is a theoretical advantage that is easily overshadowed in practice by the errors introduced by building one's own diode DBM. It is not impossible to build a home-brew DBM that performs as well as a good commercial DBM, but it is not easy, either. Just a small imbalance due to unequal winding spacing on the cores, small differences in stray capacitance, or geometric differences due to the packaging of the transistors used can easily create increased distortion products that are much worse than the 2 or 3dB reduction of noise you might realize. I'm not saying don't do it, just that the chances of improving things without causing collateral damage that is worse than the cure may not be high. Best regards, Charles ___ 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.
Re: [time-nuts] 10544A vs. 10811
Since the 10544A uses a PWM oven controller there are significant oven PWM frequency related sidebands.The PN noise floor of the 10811A (-160dBc/Hz) is significantly lower than that of the 10544A (-145dBc/Hz). Bruce On Sunday, 1 February 2015 2:57 PM, Bill b...@hsmicrowave.com wrote: I have a choice. Can I assume the 10811 is the better OCXO for phase noise and ADEV compared with the 10544A? Thanks and regards...Bill ___ 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.
Re: [time-nuts] 510 doubler
Not a good idea to use a bandpass filter even a crystal filter as such a filter has a relatively large phase shift tempco.The flicker phase noise of the filter crystal will degrade the output signal flicker phase noise significantly.Another issue is that the maximum crystal current will limit the maximum signal input to the crystal filter and thus degrade the output phase noise floor over that achievable using other approaches. Bruce On Wednesday, 28 January 2015 11:19 PM, Alberto di Bene dib...@usa.net wrote: On 1/27/2015 11:57 PM, Bruce Griffiths wrote: /The only viable solution is to use better filtering of the output of a switching multiplier./ What about filtering the doubler output with a 10 MHz xtal ? 73 Alberto I2PHD --- This email has been checked for viruses by Avast antivirus software. http://www.avast.com ___ 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.
Re: [time-nuts] [Bulk] Lucent KS-24361 / Z3810A : Strange behavior without GPS reception
Klaus, It would appear that you are still acquiring sats. I would not reach any conclusions about function until the survey is 'complete'. Currently, it is suspended. I suspect it all goes back to a poor set of signals from your GPS antenna. I don't know anything about how these units 'should operate', only how they do operate when given a good GPS signal. It would appear that your units worked normally when using the outdoor antenna. Good luck. Joe -Original Message- From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Klaus Melchior Sent: Sunday, February 01, 2015 5:48 AM To: time-nuts@febo.com Subject: [Bulk] [time-nuts] Lucent KS-24361 / Z3810A : Strange behavior without GPS reception Hi, received my Lucent KS-24361 combo, linked both units, powered them up. They tracked 8 satellites with an outdoor antenna... all fine. Repowered both units, but now using an indoor GPS antenna with bad reception. REF1 is in Locked to Ext: stabilizing frequency mode with TFOM=3, FFOM=1 and 1PPS TI +40.0 ns relative to Ext, but it is in StandBy. REF0 is ON and in Power-up: GPS acquisition mode with TFOM=9, FFOM=3. Why isn't REF1 providing the 15Mhz/1PPS signal? Here the status windows: --- Primary Receiver Status --- SYNCHRONIZATION ... [ Outputs Invalid ] SmartClock Mode ___ Reference Outputs ___ Locked TFOM 9 FFOM 3 Recovery 1PPS TI -- Holdover HOLD THR 1.000 us Power-up: GPS acquisition Holdover Uncertainty Predict -- ACQUISITION .. [ GPS 1PPS Invalid ] Tracking: 0 Not Tracking: 9 Time PRN El Az PRN El Az GPS 23:22:29 (?) 31 Jan 2015 * 1 -- --- *31 Acq GPS 1PPS Invalid: not tracking * 2 Acq ANT DLY 60 ns * 4 -- ---Position *12 Acq MODE Survey 21 17 179 Suspended: track 4 sats *25 Acq LAT N 50:34:27.066 *29 84 86LON E 6:15:59.517 *30 -- ---HGT +608.80 m (GPS) ELEV MASK 10 deg *attempting to track HEALTH MONITOR . [ OK ] Self Test: OKInt Pwr: OK Oven Pwr: OK OCXO: OK EFC: OK GPS Rcv: OK -- Secondary Receiver Status -- SYNCHRONIZATION [ Outputs Valid/Reduced Accuracy ] SmartClock Mode ___ Reference Outputs ___ Locked to Ext: stabilizing frequency TFOM 3 FFOM 1 Recovery 1PPS TI +40.0 ns relative to Ext Holdover HOLD THR 1.000 us Power-up Holdover Uncertainty Predict 432.0 us/initial 24 hrs ACQUISITION [ Ext 1PPS Valid ] Tracking: 0 Not Tracking: 9 Time _ +1 leap second pending PRN El Az PRN El Az GPS 23:24:10 (?) 31 Jan 2015 * 1 -- --- *31 59 270 GPS 1PPS Invalid: not tracking * 2 22 45ANT DLY 60 ns * 4 -- ---Position *12 17 104MODE Survey: 0% complete 21 18 179 Suspended: track 4 sats *25 56 102INIT LAT N 50:34:27.066 *29 83 80INIT LON E 6:15:59.517 *30 -- ---INIT HGT +608.80 m (GPS) ELEV MASK 10 deg *attempting to track HEALTH MONITOR . [ OK ] Self Test: OKInt Pwr: OK Oven Pwr: OK OCXO: OK EFC: OK GPS Rcv: OK Thanks, Klaus -- k...@gmx.de ___ 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.
Re: [time-nuts] 10544A vs. 10811
The other big difference is that the 10811 uses an SC cut crystal instead of an AT cut crystal. From a cold start, the SC achieves a given stability much faster than an AT cut. If you are just going to run the oven continuously (likely mode for time nuts), this isn't any big deal to you. The reason why the phase noise is better is not so much due to the SC cut crystal, but rather to the grounded base output buffer in the 10811. A 10811 is guaranteed to work in any 10544 socket in HP equipment. They had to do this so that they could stop making 10544's as soon as the 10811 was introduced. Rick Karlquist N6RK On 2/1/2015 12:54 AM, Bruce Griffiths wrote: Since the 10544A uses a PWM oven controller there are significant oven PWM frequency related sidebands.The PN noise floor of the 10811A (-160dBc/Hz) is significantly lower than that of the 10544A (-145dBc/Hz). Bruce On Sunday, 1 February 2015 2:57 PM, Bill b...@hsmicrowave.com wrote: I have a choice. Can I assume the 10811 is the better OCXO for phase noise and ADEV compared with the 10544A? Thanks and regards...Bill ___ 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 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] 10544A vs. 10811
Thanks to all for the inputs. I have both but will focus on the 10811 since the lowest phase noise and close in spurious is my objective...Bill On 2/1/2015 12:54 AM, Bruce Griffiths wrote: Since the 10544A uses a PWM oven controller there are significant oven PWM frequency related sidebands.The PN noise floor of the 10811A (-160dBc/Hz) is significantly lower than that of the 10544A (-145dBc/Hz). Bruce On Sunday, 1 February 2015 2:57 PM, Bill b...@hsmicrowave.com wrote: I have a choice. Can I assume the 10811 is the better OCXO for phase noise and ADEV compared with the 10544A? Thanks and regards...Bill ___ 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 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] 10544A vs. 10811
As I recall it, the 10544 is a BT-cut and not AT-cut. We discussed this a few years back, and even checked the cold temperature before heating up, and it matched BT-cut and not AT-cut. Anyway, go with the 10811. Cheers, Magnus On 02/01/2015 07:51 PM, Richard (Rick) Karlquist wrote: The other big difference is that the 10811 uses an SC cut crystal instead of an AT cut crystal. From a cold start, the SC achieves a given stability much faster than an AT cut. If you are just going to run the oven continuously (likely mode for time nuts), this isn't any big deal to you. The reason why the phase noise is better is not so much due to the SC cut crystal, but rather to the grounded base output buffer in the 10811. A 10811 is guaranteed to work in any 10544 socket in HP equipment. They had to do this so that they could stop making 10544's as soon as the 10811 was introduced. Rick Karlquist N6RK On 2/1/2015 12:54 AM, Bruce Griffiths wrote: Since the 10544A uses a PWM oven controller there are significant oven PWM frequency related sidebands.The PN noise floor of the 10811A (-160dBc/Hz) is significantly lower than that of the 10544A (-145dBc/Hz). Bruce On Sunday, 1 February 2015 2:57 PM, Bill b...@hsmicrowave.com wrote: I have a choice. Can I assume the 10811 is the better OCXO for phase noise and ADEV compared with the 10544A? Thanks and regards...Bill ___ 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 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.
Re: [time-nuts] 10544A vs. 10811
On 2/1/2015 2:31 PM, Magnus Danielson wrote: As I recall it, the 10544 is a BT-cut and not AT-cut. We discussed this a few years back, and even checked the cold temperature before heating up, and it matched BT-cut and not AT-cut. Anyway, go with the 10811. Cheers, Magnus On 02/01/2015 07:51 PM, Richard (Rick) Karlquist wrote: The other big difference is that the 10811 uses an SC cut crystal instead of an AT cut crystal. I stand corrected. Rick ___ 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.
