Re: [time-nuts] Very large X9.2 solar flare.
The Sun is very active this week! Lots of space weather warnings: http://www.swpc.noaa.gov/news/g3-watch-7-through-9-september-2017-due-cme-effects https://www.space.com/38057-sun-unleashes-decades-strongest-solar-flare.html http://www.swpc.noaa.gov/news/s1-warning-extended-8-september0600-utc http://www.arrl.org/news/space-weather-prediction-center-upgrades-geomagnetic-storm-watch-to-g3-strong -- Bill Byrom N5BB On Wed, Sep 6, 2017, at 04:19 PM, Alan Melia wrote: > The flare has been and gone!...is this another case of journalists > mixing up a flare with a CME ? > Alan > G3NYK > > - Original Message - > From: "Mark Sims" > To: > Sent: Wednesday, September 06, 2017 8:50 PM > Subject: [time-nuts] Very large X9.2 solar flare. > > > > It might be coming here... > > > > http://www.theregister.co.uk/2017/09/06/biggest_solar_flare_in_years_heading_our_way/ > > > > You might want to break out your eclipse monitoring equipment... > > ___ > > 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] Bulova crystal oscillator
I have a Bulova crystal oscillator, part number 1505869-1K, model number AMO31HP-V-1, NSN 6N5840-797-7659. The NSN tells me it is a little old and that it was a turn-in, probably repairable at some higher level. The frequency is marked 100.00 KHz. The oscillator voltage is 30 V DC and the oven voltage is 115 VAC. It has an octal plug on the bottom with the pins marked: 1 - oven indicator 2 - A.F.C. 3 - heater power 4 - +30 VDC 5 - case ground 6 - ground 7 - heater return 8 - 100 KC output. With the nameplate listing the frequency in KHz and the case listing the frequency in Kc and the older NSN, it appears that this oscillator was made for a longer period of time. The top has two adjustments, both with a screw cover. One is freq adj and the other is output adj. Does anyone have any data on this oscillator? What would I expect the accuracy to be? The printed frequency implies, to me, that the accuracy is in the realm of 0.001 Hertz at 100 KHz. Did I miss something here? The top also shows this to be a "Generator Reference Signal". Any insite appreciated. 73 Glenn WB4UIV -- --- Glenn LittleARRL Technical Specialist QCWA LM 28417 Amateur Callsign: WB4UIVwb4...@arrl.netAMSAT LM 2178 QTH: Goose Creek, SC USA (EM92xx) USSVI LM NRA LM SBE ARRL TAPR "It is not the class of license that the Amateur holds but the class of the Amateur that holds the license" --- ___ 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] Very large X9.2 solar flare.
The flare has been and gone!...is this another case of journalists mixing up a flare with a CME ? Alan G3NYK - Original Message - From: "Mark Sims" To: Sent: Wednesday, September 06, 2017 8:50 PM Subject: [time-nuts] Very large X9.2 solar flare. It might be coming here... http://www.theregister.co.uk/2017/09/06/biggest_solar_flare_in_years_heading_our_way/ You might want to break out your eclipse monitoring equipment... ___ 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] Very large X9.2 solar flare.
It might be coming here... http://www.theregister.co.uk/2017/09/06/biggest_solar_flare_in_years_heading_our_way/ You might want to break out your eclipse monitoring equipment... ___ 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 do I compare GPS antennas?
Hi > On Sep 5, 2017, at 10:23 PM, Hal Murray wrote: > > Was > Subject: Re: [time-nuts] GPS Antenna Feed Line Decision > > kb...@n1k.org said: >> There is pretty much no experiment you could run that would show a >> difference between the two. With a normal GPS, the “front end” of the radio >> is in the antenna. The filtering and RF amplification there determine a lot >> of things. The cable is just a chunk of wire in the middle of the system. > > Does that depend on the antenna (and location) being "good" and both coaxes > being good-enough so that the receiver always has a good signal? > Alternatively, if the signal is good, you can't tell the difference in a few > db of attenuation. It’s a cascaded noise figure problem rather than an attenuation problem. Given the noise figures involved, once you get to about 10 db of gain, the impact on the overall noise figure is negligible. > > But suppose the antenna location isn't good. How can I tell if it is > good-enough? Or how can I compare location A with location B? If your antenna location is “bad” your sky view is likely cluttered up with terrestrial “stuff”. The clear sky is “cold” and terrestrial “stuff” is hot relatively speaking. The higher the noise temperature, the less your noise figure matters. > > The best I have been able to come up requires two identical receivers. You > can verify that they are identical, or at least close enough, by running them > from a single antenna with a splitter. I haven't gotten past that. Mostly what you will measure on antenna A and antenna B is the effect of local multipath. Yes, if you have two “ideal” antenna locations to compare that will be a bit less than with normal ones. Not many of us have clear view 30 M tall concrete towers to mount our antennas on. > > Assuming you had a not-good antenna, is there any numerical scale that would > be useful to describe its goodness? At some point you simply have to dig into the theory and the math. Measure the components on a network analyzer / noise figure meter / whatever. Run the numbers and see what you get. Somewhat more to the point of Time Nuts. Your best timing solution comes from the sat’s that are straight overhead. Those are the ones with the strongest signals and the least impact of all these noise figure issues (and a bunch of other stuff). The close to the horizon sat’s are what help with the X/Y part of a survey solution ….. Bob > > > -- > These are my opinions. I hate spam. > > > > ___ > 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] How do I compare GPS antennas?
One thing that I have used is Lady Heather's lat/lon scattergram (GI keyboard command). Connect an antenna, clear the data queue (CC from the keyboard) and let it run for say 24 hours. Lather, rinse, repeat with different antennas. Compare the resulting scattergrams and see how "tight" the data is. Better antennas have less scatter in the results. If you have an ACCURATE surveyed location for your antenna, you can also use the precision survey command and see how well the results match your known location. ___ 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.