Soekris

Posted on 2010-06-17 by Nigel VH

Recently, I’ve come into ownership of a couple of soekris boxes. They’re the old 4501 model, so they’re a little underpowered compared to soekris’ more recent offerings. However, I’m not one to turn down cool free hardware, so I took the two boxes, and have been playing with ideas about what I can do with them.

However, doing anything with them requires first getting an OS on them. Now, I don’t recall if I’d ever blogged about my previous experience with a soekris box, but it was the same model, several years ago now, and a request to put FreeBSD on it. Well, some of you may know that FreeBSD isn’t always the easiest to work with, as well as the only way (available to me at the time) to get software on the box was to PXE boot it. PXE + FreeBSD + Marginally compatible embedded hardware = a few weeks of wasted time and no success.

Needless to say I dumped the idea of running FreeBSD. How about something a little easier to work with, I dunno… Debian. I found a rough tutorial of some guy who’d put debian on his soekris box. It’s an old version sure, but it ran. So, I figured, what the hell, I’ll do the same.

Through some relatively minor trials and tribulations I’ve managed to get an install of Debian 5 onto my soekris box. However, you’ll need at least a 1GB CF card. It seems the minimal install was about 600MB after everything was unpacked. Plus you’ll want to leave yourself some extra room for your files or swap space. (Some people say you shouldn’t use swap space on flash memory because it can cause sectors to go bad. This may be true, but I’m willing to sacrifice a few sectors over time to get some extra ram space when the built in only adds up to 64MB.)

I’m not prepared this evening to write the full tutorial on how to install Debian on a soekris box. First I want to experiment with newer versions / versions of Ubuntu. Once I’ve done a bit of that I’ll write a little tutorial here about how to get it on there.

For now, Nigel out.

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Once again with the lack of updates…

Posted on 2010-05-02 by Nigel VH

Well, it’s been pretty quiet around here lately. That’s mostly my fault. Alright, it’s completely my fault. Anyway, that doesn’t mean that I haven’t been doing things. I’ve just been quite busy doing those things.

Over spring break, I went down to the Black Rock desert in north-western Nevada where I and a bunch of other students at the University of Washington launched a bunch of big ass rockets. Despite the desert being quite cold, and getting sunburned despite it being cold, I think we all had a pretty damn good time. Our fasted rocket got to Mach 1.96, and a height above ground of approximately 18,000 feet. Here’s some pictures! These first few just give you an idea of where we are.

These next few show a few rockets going up and kicking ass (or having their asses kicked)

This one looked pretty good…

… until it buried itself.

It reminded me like a giant, more dangerous, rocket powered game of Jarts.

You know what you get when you Jart a rocket going Mach 1+? Destroyed telemetry systems. Damn people, Jarting the telemetry boards that I worked so hard to build!

And of course there were casualties other than my telemetry systems.

Last but not least, we had to get a picture of the whole group holding our destroyed rocket bits. If you couldn’t figure it out, I’m all the way on the left.

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Long Time, No Update

Posted on 2010-01-22 by Nigel VH

Alright, so it’s been a while since I’ve posted anything. Sorry. That doesn’t mean that I haven’t been doing things though. First, there’s been christmas, my birthday, and a whole bunch of other stuff that gets stuffed into winter break. Then there’s the start of the new quarter. Some new ham radio stuff that’s been going down. The aquisition of a dog. (doesn’t that sound formal.) Anyway, there’s more than enough for a fairly extensive blog post. So quit your whining about me not being around, and paying attention to you. I’ve got a dog to do that now.

Winter break was good. I did pretty well in my classes, but it’s always nice to have a little vacation from them. I turned 21 over the break. Nothing special there. No party, etc. I know. I’m SOOOO boring. The girl and I went on a little two day get away to Leavenworth. That was pretty fun, however, there was dissapointingly little snow… I managed to come out of the gift season with some new camping gear, a wii, and a motorcycle. All of which have been / will be quite useful / fun. After the break I went and took the written test for my motorcycle endorsement, which means I have three months to take the driving test. Here’s a pic of me on the bike taking her for our first ride.

The new quarter has treated my pretty well so far. I’ve got a fun ESS (Earth & Space Sciences) class where we’re building rockets, then taking them down to Black Rock, Nevada to shoot them off during spring break. The goal for this quarter is 20,000ft and Mach 2. I’ve been primarily working on the antennas to go into the rockets. (One of the rockets is to be made of carbon fiber, which is somewhat conductive, which poses interesting problems in using a radio transmitter inside the tube.) I’ve also been working on upgrading the ground control system as the current one has a few issues in stability and power output.

The girl and I got a dog. Her name is Buggy, but I just call her Bugs. She’s a chiwahwa / terrier mix, and I know what you’re thinking, but she doesn’t bark hardly at all and is very well behaved. Those were my requirements in getting a dog. Somehow the girl managed to find one that magically fit those. We adopted her after she was brought to Seattle to save her from a kill shelter in California.

No, the lump on her head isn’t cancer. The vet checked it out, and said that it’s just a fat deposit and she was probably born with it.

I’ve been increasingly exploring some of the interesting things that you can do as a HAM radio operator besides chatting with people from varying distances. Lately I’ve been exploring satellite communications. There have been groups of HAMs that will put together a small satellite, and get NASA or some other country’s space agency to put it up on the cheap. These satellites act like normal ground based repeaters, which allow someone to talk on the repeater’s input frequency, and the repeater will re-broadcast it on the output frequency. This allows people to talk to people from distances they wouldn’t normally be able to reach. In the case of a satellite, if the conditions are right, and the satellite is passing over the right areas, you can cover the continental U.S. These types of communication offer interesting challenges in terms of signal strengths and antenna designs. My normal antenna has not been performing very well for this and I decided to build a new antenna that would suit this situation better.

I chose to use a Yagi / Uda antenna. Yagi and Uda refer to the names of the two guys who originally designed the type of antenna. The design focuses the radio waves in one direction, giving you what’s called “gain.” This means that you have a better chance of reaching your target, and you have a better chance of hearing them as well. Anyway, I needed to cover both the 2 Meter band and the 70 Centimeter band with the same antenna, so after some searching on the internetz for ideas (http://www.mydarc.de/df8gh/modejbyagi.htm), and a lot of time with some modeling software, I managed to turn this…

…into this…

If you want to know more about this specific build, I plan to put up a page about it’s info and construction in the projects section here pretty soon.

Anyway, that’s what’s been going on. Hope it was worth the wait.

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Radio Projects

Posted on 2009-12-09 by Nigel VH

A few days ago the girl came home with a subminiature PC case. It had a mobo in it, but was toast, so I decided to repurpose the case into something useful. I took my 13.8V power supply, a backup battery, my ham radio, and I stuffed them all in there. I think it turned out pretty well.

You can see that under the radio is an open bay that I’ve left open so that the cooling fan can easily pull cool air in for the power supply. You can see the indicator light with the three switches. The light means that it’s on. (NO WAY!!) As for the switches, from left to right they turn on the main power supply, the backup battery, and the cooling fan. You can also see the mic mentioned in the last post, and the SWR bridge I talked about quite a while ago.

I’ve also gotten a used trunking scanner off of ebay so I can listen to the local metro, police, and fire departments.

The Seattle area uses a large trunking system for all sorts of local radio communications. You can just listen to the frequencies, but the trunking system’s computer moves the conversations around between frequencies all the time to most efficiently use air space, so it was essentially impossible to hear whole conversations with my normal radio. The trunking scanner listens to the control computer, and changes frequencies automatically to follow conversations. So far, I’ve found the most interesting things to listen to have been the fire dispatches, as well as the metro system. The police are there, but most of what they’re doing are vehicle registration lookups, and the rest is in codes I don’t know.

Last for this post is an admission of guilt. I’ve gone to the dark side. I got an iPhone. However, I make myself feel better about it by reminding myself that I didn’t get it new, I didn’t have to do the two year contract, and it’s not a recent model. In fact it’s the first model of iPhone. The girly had it, and then just two days ago upgraded to the new one. My original plan was to use it as an iPod Touch, however, I got sucked in and am now using it as my phone. I’d also like to think that I haven’t been as horribly addicted to it as some people are when they first get their iPhones. Perhaps it’s because I’m used to using one and having one around, seeing as the girl’s had one for a few years now. Anyway, so far it seems to be working pretty well for me. For you picture whores, here’s an unremarkable shot of it on my desk.

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Yaesu MH-48 Microphone Mod

Posted on 2009-12-05 by Nigel VH

You’ve all known for a while that I’m a HAM radio operator. Recently I was reading around online about things that people have modified on my model of radio to improve performance, expand range, etc. One of the things I came across was a mod for the yaesu mh-48 mic rather than the radio itself, but it seemed just so handy I had to do it to mine.

The display on my model of radio is backlit, but unfortunately the buttons around the display aren’t, so if it’s dark, you can’t read what any of them say. Kind of a problem… Anyway, A guy on the internetz named Dwight (N7KBC)(Thanks for the great instructions!) decided to add a few superbright LEDs to the back side of the mic, and wire them into the key lock switch which he (and most other people) didn’t use.

The instructions are within a restricted Yahoo group for people who own the Yaesu FT-8900, so I won’t post them, but if you have one, join the group, and it’s called “Better than Backlit keys ver 2.”

However, I will post the pictures of my mic’s insides and compare them to clippings of the photos N7KBC provided in the instructions. They’re mostly the same, but I did a few things slightly differently.

Here’s the insides of my microphone, the back is on the left and the front is on the right. You can see the added resistor next to the larger set of red and black wires that run to the back half to the LEDs.

Here’s N7KBC’s mic. You can see here that he used much smaller wires than I did. That’s mainly just a matter of what each of us had around. He also used wires to connect the resistor to the two points. We both used the same points, but I just used the leads from the resistor instead of wires.

Here’s the front of my mic, pretty stock…

Here’s the back of my mic with the LEDs in.

And finally here’s the mic showing the lights on. Sorry this isn’t very impressive, it’s actually quite bright, but you know cameras and taking pictures in dark situations…

Thanks again Dwight N7KBC for the great set of instructions for this very useful mod!

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