Archive for July, 2010

Tinfoil hat (for EVDO)

July 28th, 2010

The things you’ll do when you’re sitting around the house…

The other day I built a parabolic reflector out of cardboard and some foil tape I had lying about. I was researching various homemade antenna designs I want to tinker with and stumbled on one that I actually had all the parts for on hand. As we are so close to the edge of EVDO reception here that moving down the hill a few feet would kill the signal, it seemed like it would be worth a shot. After all, it cost maybe fifty cents for the foil tape I used and the cardboard was free.

Parabolic EVDO Antenna.

Now, this is hardly a good mobile solution as it’s fairly directional, but after spending twenty minutes or so on the roof pointing the reflector and testing bandwidth, I got pretty good results. The SNR increase doesn’t even register on the cradlepoint’s web interface, which is fairly lackluster, so I had to result to ping flooding our upstream router to detect a better signal. No, I didn’t DoS it, I kept the packet count to 100 at a time while aligning and 1000 packets for bandwidth testing.

I didn’t record all the numbers, but to give you an idea of the improvement: without the reflector, we were seeing 10-30% packet loss and average roundtrip times that ranged from 5 seconds to 9.5 seconds. Even at that, the connection was usable. Once the reflector was aligned, packet loss dropped to 0-1% and average roundtrip times stayed about 2.5 seconds. This equates to a 100-300% increase in bandwidth plus the bandwidth recovered from dropped packets.

The connection is hardly blazing fast, but it’s quite a bit more usable than previously. For our normal usage patterns, it’s actually quite acceptable. Bear in mind that our average roundtrip times are similar to 380ms. The previously stated times are for icmp packets being sent out as fast as possible and saturating the connection.

With that sort of improvement, I’m much more determined to build a waveguide antenna for times when we’re having trouble hitting a tower. Bonus points if I can fit both the wifi and 3g spectrums into the same antenna and use it for a wifi repeater as well.

Rainy day… came our way…

July 25th, 2010

We’re back on the move again and slowly making our way through Texas in what can only be described as damn hot weather. More importantly though, the household has expanded. While we were at Caverns of Sonora, the ranch manager’s dog had a litter of puppies. After much hemming and hawing over whether or not we could care for a dog in this lifestyle, we finally decided that if we didn’t have the time for a dog now, then we never would.

Rain enjoying homemade hail on a hot day.
Rain enjoying a cool ice ball on a hot day.

So, making her Internet debut, we present Rain. Her parents are both working dogs that have worked cattle, sheep and goats in all sorts of weather ranging from snow and ice to hotter than hell southern Texas. Casey, her mother, is a blue heeler and her father is Slick, a border collie. Odds are pretty good that she’s too smart for either one of us, but with a little luck and a lot of treats, maybe she’ll tell us what we’re doing wrong.

The first few days, there was a lot of tension between her and the cats, but they are slowly getting used to her and only hissing when she gets seriously into their personal space. I’d rather not talk about my scars when she met Hunter the first time, though. Rain seems to be adjusting to a nomadic lifestyle much better than she liked the first couple of weeks while we were still working. Rather than spending so much time locked up to stay safe from the cats, she gets to go where we go and do what we do. In less than a week since we left the cave, she is already a different dog, and apparently, much happier!

Oh, if you were wondering, she’s currently 8 1/2 weeks old and her birthday is 5/25 if you want to send her presents.