KD0FNR Rockmite Booms into North Carolina on 20 meters... In The Dark!!!

The ionosphere has been doing reallyfun things on the 20 meter amateur radio band the last two mornings. The Rockmite is 20 dB into North Carolina at 11:00 GMT! (In the dark.)

The F2 layer of the ionosphere is 428 km up, and isn't supposed to be useful at 14058.4 MHz with an maximum Usable Frequency (MUF) of 13.36 MHz, and yet!

I'm guessing the grey line near the receiving staions on the map can't hurt. I'm not hearing any stations sending the other direction, yet.

Update 3/20/2023: I finally heard a station from South Carolina this morning at about the same time, (ok, ok, it was more like 4:30... I slept in.) Sadly, this morning, my signal did not seem to be making the return trip as my spots were limited to Berkeley, locked soundly in the ground wave range from San Francisco. Interestingly, the ionogram for California showed conditions that might have supporoted the trip:

They just didn't.

For those curious, and new to ham radio, the app I use to determine how far the little radio reaches is called the reverse beacon network. It's a network of software defined radios (SDR) that listen on a variety of frequencies to the ham radio bands. The networked SDRs automatically decode Morse code (CW) and report the callsigns they hear to a central server.

Here's the MUF chart at the time.

Comments

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 ...

The Alcubierre Warp Drive Tophat Function and Open Science with Sage

I transferred yesterday's Mathematica file with the Alcubierre warp drive[2] line element and space curvature calculations to the +Sage Mathematical Software System today, (the files been added to the public repository [3]). If you haven't used Sage before, it's a Python based software package that's similar in functionality to Mathematica. Oh, and it' free. I also worked a little more on understanding the theory, but frankly, I made far more progress with the software than the theory. What follows will be a little more of the Alcubierre theory, plus, a cool Sage interactive demo of one of the Alcubierre functions[1], as well as a bit about my first experience with using Sage. Theory The theory is fun, but it's moving slowly. Here's the chalk board from this morning's discussion Alcubierre setup the derivation using something called the 3+1 formalism which means we consider space to be flat, (in this case), slices that are labelled ...

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...

Copasetic Flow

Search This Blog