[Elecraft] Elecraft compatible WX station

[EricJ]

I've been wondering why there isn't an alternative to cup anemometers 
for this application since the technology isn't that new.

google rc airplane pitot tube and you will come up with a large 
practical knowledge base for building them. I build them in about 2006 
with a Freescale MPX5100 sensor (might be better sensors available 7-8 
years later). You still need a strong weather vane to keep the pitot 
into the wind, but that's easier to make robust than a manic cup 
anemometer at high speed.

Mine worked pretty good down to about 10-12 mph, but wasn't very 
reliable below that. I gave it a couple of rides on the bike and it 
worked to 130 mph and specs suggest it could go a lot higher. Anyway, if 
it blows away in a hurricane, knowing the wind speed is probably the 
least of your worries.

I've used the same type sensor to make a cylinder balancer for my BMW 
R1100RT. In both cases, it was read with very simple software on an 
Arduino. RC places sell complete kits for $25-50 so it would be easy to 
experiment with. Make sure it is capable of stand alone operation.

Far off Elecraft topic, but it will be my only reflector post on the matter.

Eric
KE6US





On 3/2/2014 11:28 AM, Bill Frantz wrote:
> Many years ago I talked with the professionals on the top of Mt 
> Washington, New Hampshire (record wind: 241 MPH and the anemometer 
> blew away). They say the the cup type anemometer tends to act like a 
> helicopter at about 100MPH and fly away.
>
> They use pitot tubes to measure wind speed. This is the same device as 
> the one used to measure airspeed on an airplane. It looks like a 
> tapered tube with a hole in the end, usually mounted on the leading 
> edge of the wing on a light airplane. The difference in pressure 
> between the end of the tube and a "static" source, unaffected by the 
> wind, gives the speed.
>
> A weather station using a pitot tube would be a good idea for high 
> wind environments.
>
> Cheers - Bill, AE6JV