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Who is this guy?
• Data Geek
• Licensed in 1991
• APRS since 1991
– WetNet
– Xastir
• Interested in weather for 50 years
• Weather Station since 1995
– Davis WM II
2
Why report the weather?
• Personal Impact
– Sailing
– Search and Rescue
– Data
• Public Service
– CWOP
– NOAA/SKYWARN
3
APRS
Automatic Position Reporting System
• © Bob Bruninga
• GPS Position Reporting
• But much more
– Search and Rescue
– Messaging
– Weather
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N7QNM Weather
• Combine APRS and Weather
• Get involved in CWOP
• Old Weather Station
• Linux Bigot
• 1995
• Xastir
• Meteo
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Components
• Weather Station
• TNC
• Radio
• Antenna
• Solar Panel
• Charge Controller
• Battery
• Solar Panel Bracket
• Stevenson Screen
• Mast/Mount
• Box for Radio/Battery
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Weather Station
• Argent Data ADS-WS1
• Dallas Semiconductor 1-wire based
• TNC/WX All-in-One
– Wind Speed/Direction
– Temp/Humidity
– Barometer
– Rain Gauge
• Inexpensive
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Antenna
• Vashon Radio Club J-Pole at 12’
– 1ST model
• Cushcraft Ringo at 22’
– Improved digi/igate coverage
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Solar Panel
• Harbor Freight
– 5W Panel
– Discontinued
• New/Better technology
– 50W in almost the same form factor
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Charge Controller
• 3A Controller from All Electronics
• �http://www.allelectronics.com/make-a-store/item/SCN-1/3A-SOLAR-PANEL-VOLTAGE-CONTROLLER/1.html
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Battery
• Radio Shack 7AH Sealed Lead Acid
• 1st one failed
– Exceeded power budget due to weather station transmit parameter
• Current battery in service for over 1 year
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Solar Panel Bracket
• 1st Attempt
– Home Depot aluminum angles
– Too flimsy
• Custom fabrication
– ¼” Aluminum tubes
– Tork-Lift Welding (Kent)
– $125
• Oriented due South – 18 degree tilt
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Stevenson Screen • Keeps direct sun and rain off the
Temp/Humidity sensor
• Ambient Weather
– SRS100LX
– www.ambientweather.com
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Mast/Mount
• 1” 10’ Radio Shack mast
• 5’ section in a 5 gallon bucket of concrete
• Guy wires in 1 gallon (10 lb) buckets
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Box for Radio/Battery
• Cutler-Hammer from Home Depot
• Plywood backing for terminal strip
• Sealed against weather
• Heat dissipation apparently not an issue
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Power Consumption
• Weather Station 100 mA (max)
• Radio
– Receive – 16 mA muted
– Transmit
• 700 mA (low)
• 1.6A (high)
• Duty Cycle – 2 minutes on every 20
• Initial Budget ~800mA = .08AH
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Power Input
• 12 V (nominal) panel
– Actually between 10 and 15 V
• 5 W Rating
• De-Rate 50%
• Worst case 200 mA = .2AH
• Duty Cycle
– 3 hours/day in mid-winter
– 12+ hours/day in summer
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Power Realities
• Being conservative was the right approach
• Weather station parameters
– Change in wind direction triggers transmit
– Initially set to 20 degrees
– Transmitting every 2 or 3 minutes during wind events
• Need high power to hit digipeater/igate
– Inversions common in winter
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Real Consumption
• Transmit Avg about 5 times/hour
• Power consumption close to 2A during transmit
• .2AH (instead of .08)
• Break even power consumption
• About 35 hours of battery life with no charge
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Construction
• 5 Gallon bucket with 2” pipe
• Sealed Cutler-Hammer box to contain radio and battery
• Weather Station in Stevenson Screen
• Mast and Antenna on Solar Panel Bracket
• Terminal Strips for wiring
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Testing
• Back yard at old home
• Sensors sheltered from wind
– Missed the wind direction issue entirely
• Used 5 Gal bucket w/2” pipe as temporary support
30
Improvements
• Added a 10’ mast section
• Changed antenna
– Cushcraft 2M Ringo
• Change reed switch in rain gauge
32
More Improvements
• Additional 1-wire Sensors
– Soil Temp
– Insolation (Solar)
• Cloud Cover
– Steel Ball and Camera
• Changes to Xastir
– Weather Server
– Record weather from other stations
33
Weather Network
• KC7RAS-8
– Columbia Center in Seattle
– ADS-WS1
• Hard power
• Aspirated Box
• Mocom Exciter
• Anemometer failed at 60K
• N9VW
– Has my old Davis WMII
34
CWOP Details
• 10,000 Registrations
• 6,000 active stations/day
• 40,000+ observations
• “Ground Truth” for NOAA/NWS
– Another Amateur Radio Public Service
36