[Skimmertalk] More Primary Frequency Standards for the RBN

[Pete Smith N4ZR]

I have to begin with an apology - this e-mail is being sent to the 109 
most active RBN contributors.  Some of you I have met, and many of you 
I've corresponded with, so I hope you'll excuse this impersonal way of 
communicating, but the mailing list was generated automatically and it 
seems like the best way to reach all of you at once.

We're interested in helping RBN ops to improve the frequency calibration 
of their Skimmers.  It's not that things are bad - not at all - but we 
think they could be better, particularly now that we are spotting RTTY 
to the nearest 10 Hz..

You probably knowabout the "skew" system on our Detailed Skimmers page 
on the web site, but for those who don't:

We have a couple of stations, one on the East Coast of the United States 
and one in Central Europe, which the RBN team quietly designated 5 years 
ago as primary frequency standards.  When they are on the air, making 
spots, other stations hearing the same stations are compared with them.  
If they are "spot on," they are designated as additional temporary 
standard stations, meaning that for a period of time they too are used 
as standards of frequency comparison, in the same way

Every spot that is sent to the RBN servers is compared with the standard 
stations, and if the same spot is found, a "skew" is calculated - that 
is, the difference plus or minus, from that station's spot.  If the skew 
is greater than +/- 0.1 KHz, a notice is sent to the Skimmer station's 
Aggregator,and displayed for the operator.

If you look at the detailed node list on the website, you'll notice that 
for most stations, only a minority of their current bands show a "skew" 
value at all.  That's because they haven't spotted any stations on that 
band in the last 15 minutes that have also been heard by a standard 
station.  A "-" on the band simply means no data.

We think we can do a lot better. If we have more standard stations, more 
widely distributed, Tjhat's why I'm writing to you.

If you have some means of determining the frequency of your Skimmer 
receiver that is better than the standard local oscillator in the 
receiver - a temperature-controlled oscillator, a rubidium standard or 
an oscillator disciplined by GPS, we'd love to hear from you. Please 
drop me a note telling me what you're using.  This will not affect how 
you use your Skimmer in any way. Everything is done at the RBN server, 
and if your station becomes one of our standards, we won't tell anybody.

-- 

73, Pete N4ZR
Check out the Reverse Beacon Network at
http://reversebeacon.net,
blog at reversebeacon.blogspot.com.
For spots, please go to your favorite
ARC V6 or VE7CC DX cluster node.