Time To Pull The Plug

This is a subtitle. There are many like it, but this one is here.


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I’ve been working on a golang wrapper library for libnecpp from nec++, a C library interface for a C++ rewrite of nec2c, which is a C rewrite of the original FORTRAN NEC2.

That wrapper is in a pretty good state (although like so many projects not “done”, as such), and you can find it on github at https://github.com/ctdk/go-libnecpp. There are godocs for the library as well.

Areas for future work include:

  • Improve the documentation and variable names by reference to the NEC2 user manual.
  • Add more utility functions for tasks like reading NEC card decks, getting the gain at different θ and φ angles, that sort of thing.
  • Being able to either spit out data for other plotting programs to use, or make its own plots of antenna radiation patterns, would be neat too.

NB: To successfully build go-libnecpp, you need to have nec++ installed on your system. Most Linuxes should have it available (probably under the name necpp) in the distro packages, but if not you’ll need to build it yourself. On some platforms, like Mac OS X, this can be a bit of an ordeal.

Modern-xiafs Updated for 4.9.6, 4.10.1

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Once again, the modern-xiafs kernel module has been updated, this time to cover kernels 4.9.6 and 4.10.1. (Strictly speaking it was updated a few weeks or so ago, but only now am I getting around to noting that fact.) These kernels each have separate branches (linux-4.9.6 and linux-4.10.1, respectively) that need to be used to build the right module for that kernel. As usual, even if your current kernel doesn’t exactly match one of the kernels modern-xiafs has been built against, a branch that’s close to it may work.

The usual warnings, as always: you’d be crazy to use this on a production box, and while it should work fine it could conceivably blow your computer up or something. Don’t forget the whole 2GB volume/64MB max file size limitation either.


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As a little learning exercise, I’ve written a calculator for Moxon antennas in Java as a command-line utility called moxoncalc.

Given a frequency in megahertz and a wire size, moxoncalc will spit back to you the dimensions of a Moxon antenna designed to work at that frequency. By default it includes a diagram of what a Moxon looks like, but there are also optional formats with a short display that merely lists the dimensions of the sides and elements and a JSON rendering of the short display. It doesn’t yet give you NEC decks to model the antenna, but it might later.

Modern-xiafs Updated to 4.7.10, 4.8.7

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The modern-xiafs kernel module has been updated to work with (at least) the 4.7.10 and 4.8.7 versions of the Linux kernel. That code is in the current master, but also lives in the linux-4.7.10 branch.

There’s also a small fix for mkfs.xiafs – there was a bug with setting the umask (or, at least, there was a typo in the original program and it was trying to set the umask in a totally obsolete way) that made it so any filesystem created with it would have totally open permissions. Now, it uses the default umask like one would expect. This fix has been added to the branches for older kernels as well.

Usual warnings: you’d be crazy to use this on a production box, and while it should work fine it could conceivably blow your computer up or something. Don’t forget the whole 2GB volume/64MB max file size limitation either.

Modern-xiafs Updated to 4.x Series Kernels

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It’s rather been a while since I’ve worked on the xiafs module, but while I was flying to NYC last week I ended up working on it some on the plane and got it caught up with more the recent Linux kernels.

Specifically, kernel version 4.0.9 still works with the 3.16.4 branch, so there were no changes there. Kernel version 4.1.3 and kernel version 4.4.0 had very small updates, so they have their own branches. I haven’t tested any 4.2 or 4.3 kernels, but I expect they would work with one or the other of those branches.

The usual warnings about this still apply; you’d be crazy to use this on a production box, and while it should work fine it could conceivably blow your computer up or something. Don’t forget the whole 2GB volume/64MB max file size limitation either.

Astro Log: December 30th, 2015

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Equipment: Orion Skyview 6 Deluxe EQ, Nikon 10x50 binoculars (new item), 32mm TeleVue Plössl eyepiece (new item), 9mm Planetary eyepiece.

Previously viewed objects: Messier 42, Messier 45, Messier 31

Not much of a night out, but I did get to try out the TeleVue 32mm Plössl eyepiece I picked up a couple of months ago finally, along with the 10x50 binoculars I got for Christmas. Both were very nice, but while it was a reasonably clear night it was awfully humid. The eyepieces and the binoculars were fogging up a lot (hairdryer to the rescue there), and there was rather more of a haze than I like. I used the 6” scope instead of the Dob because I didn’t want to move a bunch of wood from a woodworking project I’ve been working on when what I mostly wanted to do was test out a particular eyepiece anyway.

The Orion Nebula looked amazing in the new 32mm, though. The binoculars were also really nice, but I think they’ll really shine when I’m out in the dark somewhere and can use them to look at some truly large structures. I think one of those folding chairs you can lay down in would be helpful, though; the 10x50s are small enough that you can use them without a tripod, but they’re still a bit heavy to hold steady and crane your neck at weird angles.

Astro Log: July 17th-18th 2015

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Equipment: 16” Dobsonian, 102mm Maksutov-Cassegrain telescope, 55mm, 32mm, 25mm, 12mm TeleVue, 9mm & 6mm Edge-On Planetary eyepieces, Paracorr, 12mm illuminated reticle eyepiece.

New objects observed: NGC 6426, NGC 6118, NGC 7142, NGC 5976A, NGC 5981, NGC 2403, NGC 2655, NGC 2715, NGC 6356, NGC 6342, NGC 6217,

Previously viewed objects: Venus, IC 4665, Messier 7, Saturn, Titan, NGC 5557, NGC 5866/“Messier 102”, NGC 5907, Messier 31, Messier 32, Messier 110, NGC 404, Messier 33, NGC 6633, Messier 51, NGC 5195, NGC 7000, NGC 7009, Messier 13, NGC 6207

Once again, I went to the Tacoma Astronomical Society’s Goldendale star party, and a fine time was had. This year I took my daughter with me, and while she only spent a little time observing and kept going to bed early, I think she had a decent enough time.

This year I brought two telescopes: both the trusty 16” Dobsonian, and the 102mm Maksutov-Cassegrain I picked up back in December that I haven’t been able to use much. I wanted to take some time trying out the Mak-Cas at a dark site, and while I didn’t spend as much time with it as I did with the Dob, I got some very nice views of Saturn with that telescope. I also tried out the illuminated reticle I got for Christmas and did a very good polar alignment with the Mak-Cas. It ended up being accurate enough that actually turning the RA knob knocked it more out of alignment than anything else, so I think that was a success. I’m not sure if it was quite an astrophotography quality alignment, because the mount itself wasn’t as stable as it should have been, but it’s worth experimenting some more.

I also got a lot of use out of the adjustable chair I also got for Christmas. I swear, this is one of the best things I’ve ever bought for myself. No longer do I need to make myself an absolute wreck by contorting myself for hours to look through the telescope. I also learned a neat trick to rub Pledge on the moving surfaces of the Dob (on the Teflon pads and the Formica) to help it move smoothly and not stick. I haven’t fully reassembled it yet, but already it seems to be moving like a dream. I had noticed that it was harder to use lately, but thought that it was just me.

As far as observing went, I had a pretty good go of it on these nights, as you can see above. I observed quite a few more new objects, and M51 was particularly noteworthy in its appearance. I could see well defined spiral arms in that galaxy. I should have looked at M81 to see how it looked in those skies, but failed to get around to it.

Astro Log: June 7th 2015

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Equipment: 16” Dobsonian, 55mm, new 9mm & 6mm Edge-On Planetary eyepieces, Paracorr

New objects observed: Iapetus

Previously viewed objects: Saturn, Titan, Tethys, Dione, Rhea

It’s been a pretty brutal time for trying to get viewing time in for a while now. It was finally “clear” last week, so I took the Dobsonian out to try out the Edge-On Planetary 6 and 9mm eyepieces from Orion that I got a while back. I tried to knock off some Herschel 400 objects, but it just wasn’t in the cards for me that night. I did get a look at Saturn and saw five moons: Titan, Dione, Rhea, Tethys, and Iapetus. Iapetus, as far as I can tell from my notes, is a new one at least. Unfortunately planets aren’t so great in the Dobsonian, but Saturn looked reasonably attractive as usual — just not as clear as I might have liked. No complaints about the eyepieces, though. I want to try them with a faster telescope sometime, and in better (and clearer) skies to see how they perform there.

Moving Along

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I am sad, but also excited, to announce that after 11 years I am leaving Daily Kos and joining Raintank, where I will be working on monitoring software and doing devsy-opsy.

It’s been a long and interesting ride at Daily Kos. I went through many election cycles, met lots of interesting people, learned a lot of things, had to solve a lot of difficult problems, and worked with some amazing people. It’s the only job that my kids have ever known me to have. Hell, Daily Kos even once saved my life.

I’m sad to be moving on, but I’m very excited about what I’ll be doing now. It doesn’t have the glamour of politics, but monitoring is important. I’m looking forward to it.

Kossack friends, I’ll still be on Twitter, reading the site, and hopefully poking my head up from time to time. Rest assured that my political opinions remain unchanged, and that I will not become a conservatist once I’m out the door. You’re in good hands with the rest of the tech team; they do good work, and you won’t have any problems with them. One nice thing about my moving on, actually, is that it provided the catalyst to address a lot of tech debt that had accumulated over the years, so it should be even smoother now in many ways.

Good luck, and farewell. See you on the Internets.