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boiler off, 2012
Saturday, March 10 2012
The weather was looking like it was going to be warm all week, though today was destined to be sunny and cold. Since I usually shut down the household boiler in late March (and I only really need it for heating the laboratory) I decided to take a risk and shut it down for the season today. This involves throwing a switch and turning a knob in the basement, and whenever I do these things I find myself uttering the noise of a large complicated engine powering down (as heard in a Hollywood sound effect): NEERNEERNeerneernehnehnhn...
Despite the finger-numbing cold, this afternoon I did some more WiFi experiments in the nearby forest, this time without the assistance of Ramona the dog. First I set up one of the cheap Chinese yagi Wifi antennas on the laboratory deck, pointed it down the Stick Trail, and connected it to a cheap D-Link router. Then I went to that bluff where I'd done my WiFi testing the other day and tried to get the signal using a laptop, a WiFi dongle, and another cheap yagi. I was just barely able to pick up the signal at the bluff, which seemed to indicate that the yagis are almost worthless; indeed, substituting a stubby rubber ominidirectional antenna for the yagi was almost as good.
Back at the house, I did some research to see what exactly the specifications for a 2.4 GHz yagi should be, but it's hard to find any definitive information. Some yagi designs call for the spacing between the parasitic elements to vary (usually being farthest apart at farthest distance from the driven element), though some (like the cheap yagis I have) are spaced uniformly. One calculator also suggested that the 5.2 centimeter length and 2.4 centimeter spacing of the elements on my cheap yagis is correct, so it's possible (though unlikely) that the only thing wrong with them is a terrible SWR in the 1.5 meters of cheap 75 ohm cable.
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