Anemometer (Wind Sensor)

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There where some problems with the Anemometer this week, or as I prefer to call it, the Wind Speed Sensor (much easy to say Wind Sensor, try saying Anemometer 3 times in a row).

The weather station is starting to show it's age a little and the small solar panels on the 2 transmitters don't seem to work as well anymore. This results in the 2 transmitters eating through camera batteries every couple of months and a lower transmit signal. Since the Wind Sensor is 300 metres away from the receiver / weather computer / house, as soon as the power level gets a little low, we loose the wind sensor data. This starts to happen just after sunset normally. The solar panel should generate enough power to run the transmitter all night (it charges a capacitor) however will drop back to the backup camera batter if there isn't enough charge in the capacitor. Once the camera battery gets a little low, the situation is reached where the wind sensor data is lost soon after sunset.

So, I decided to upgrade the standard transmitter antenna with a high gain Yagi antenna to try to give a better signal. Since it only transmits with 10mw of power, even at the best of times, the weather station receiver needs to be very carefully placed on a windowsill to get a signal. Of course nothing ever goes smoothly and there where some problems. Firstly a bad solder joint for the new antenna plug and then a problem with the coax being poor quality. Finally, I got some decent coax and now I have a stronger signal then ever from the wind speed sensor transmitter. I can even move the weather station receiver to a more convenient spot than the windowsill. Mission complete.

There are some more planned upgrades for the wind speed sensor. I've noticed that in very light winds the wind vane seems to stick a little, so it is coming down so I can take a look at it and I'll also check the rotation on the wind speed sensor. Hopefully I can free the wind vain up with some grease, however with these consumer based items, like most things nowadays, they are really non repairable and throw away items unfortunately. A new wind speed sensor / wind vane is $220.00.

When I take down the mast I will be replacing it with a second hand tower I picked up from an amateur radio operator in Cobram (and if you thought it was hot here, go for a drive to Cobram during summer !) . The new tower is a few metres higher and will help clear the pine forest to the West which creates some turbulance to the current setup, even though it is currently higher than the tops of the pine trees. The result should be less gusty wind speed data from the west.

Hope all that makes some kind of sense !

Cheers
Steve