Skip to main content

Today I Learned: Reverse Beacon Sometimes Truncates Callsigns

 This is kinda interesting, and gives me a bit more faith as well as a bit more data in and about the Rockmite. (Funny how those two things—faith and data—often go hand in hand.) The Reverse Beacon Network, (RBN), uses software to decode Morse code. The software is quite good, but today I found out it's not perfect. While working on my own python script for reading the telnet data stream that feeds the RBN site directly, I typed in a search string for my callsign—KD0FNR—as KD0*. Then, I tried doing the same thing on the RBN web site. The results I got back were unexpected, but answered a lot of questions.

RBN map showing KD0F* QSOs

Callsigns that were variants of mine like KD0F, KD0FN and KD0FX were returrned. A lot of them appear to actually be my callsign misinterpreted by the software Morse code decoder, and tell a story of the radio's operations that fill in the gaps I've been wondering about up until now.

KD0FN is almost certainly me since a review of the FCC database reveals that callsign is no longer active. KD0FX? Also me in almost all certainty. if you leave off the last dit of KD0FNR it translates to KD0FX.

To further pare down the results, I also sorted by the frequency of the spotted stations. The Reverse Beacon Network has only spotted the Rockmite's full callsign—KD0FNR—on the following 4 frequencies over the last few months:


Given a method to look at these other callsigns, what can we find out?

Why doesn't CA hear me on ground wave?

Apparently they do on occasion,


when it's about 4 in the morning here in San Francisco; when the ionosphere is completely shut down. About exactly when you'd expect groundwave propagation to be detectable.

But, is KD0F someone else? It doesn't seem likely. A search on the specific call sign reveals activity that only lines up on the limited set of frequencies the Rockmite 20 supports.

The rockmite occasionally hits Hawaii, why not further East?

Again, the answer is that well, occasionally it probably does. Looking back a few months, we once again see KD0F, but this time the station was spotted in North Carolina. 


The timing fits, and once again it's on one of the Rockmite's frequencies.The timing in fact fits remarkably well as it occurred at 16:46 PST which is the same half hour during which the Rockmite reaches Hawaii.


Takeaway:

I need to log my radio operation activities more completely to provide an additional check for reseults like the ones shown above, but the radio is doing more than I thought it was. It's operating in a manner that actually makes sense.

Anyway:

There's also really cool stuff to be done here using a github screen scraping as outlined by Simon Willison's example of mapping PG&E outages over time. Similar things would help to analyze how the radio is working.



Labels:

Comments

Post a Comment

Please leave your comments on this topic:

Popular posts from this blog

More Cowbell! Record Production using Google Forms and Charts

First, the what : This article shows how to embed a new Google Form into any web page. To demonstrate ths, a chart and form that allow blog readers to control the recording levels of each instrument in Blue Oyster Cult's "(Don't Fear) The Reaper" is used. HTML code from the Google version of the form included on this page is shown and the parts that need to be modified are highlighted. Next, the why : Google recently released an e-mail form feature that allows users of Google Documents to create an e-mail a form that automatically places each user's input into an associated spreadsheet. As it turns out, with a little bit of work, the forms that are created by Google Docs can be embedded into any web page. Now, The Goods: Click on the instrument you want turned up, click the submit button and then refresh the page. Through the magic of Google Forms as soon as you click on submit and refresh this web page, the data chart will update immediately. Turn up the:
Post a Comment
Read more

Cool Math Tricks: Deriving the Divergence, (Del or Nabla) into New (Cylindrical) Coordinate Systems

Now available as a Kindle ebook for 99 cents ! Get a spiffy ebook, and fund more physics The following is a pretty lengthy procedure, but converting the divergence, (nabla, del) operator between coordinate systems comes up pretty often. While there are tables for converting between common coordinate systems , there seem to be fewer explanations of the procedure for deriving the conversion, so here goes! What do we actually want? To convert the Cartesian nabla to the nabla for another coordinate system, say… cylindrical coordinates. What we’ll need: 1. The Cartesian Nabla: 2. A set of equations relating the Cartesian coordinates to cylindrical coordinates: 3. A set of equations relating the Cartesian basis vectors to the basis vectors of the new coordinate system: How to do it: Use the chain rule for differentiation to convert the derivatives with respect to the Cartesian variables to derivatives with respect to the cylindrical variables. The chain
10 comments
Read more

The Valentine's Day Magnetic Monopole

There's an assymetry to the form of the two Maxwell's equations shown in picture 1.  While the divergence of the electric field is proportional to the electric charge density at a given point, the divergence of the magnetic field is equal to zero.  This is typically explained in the following way.  While we know that electrons, the fundamental electric charge carriers exist, evidence seems to indicate that magnetic monopoles, the particles that would carry magnetic 'charge', either don't exist, or, the energies required to create them are so high that they are exceedingly rare.  That doesn't stop us from looking for them though! Keeping with the theme of Fairbank[1] and his academic progeny over the semester break, today's post is about the discovery of a magnetic monopole candidate event by one of the Fairbank's graduate students, Blas Cabrera[2].  Cabrera was utilizing a loop type of magnetic monopole detector.  Its operation is in concept very sim
Post a Comment
Read more