Re: [time-nuts] Very large X9.2 solar flare.

[Bill Byrom]

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

[Glenn Little WB4UIV]

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.

[Alan Melia]

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.

[Mark Sims]

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?

[Bob kb8tq]

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?

[Mark Sims]

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.