Karl Berger

Karl Berger

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  1. Important Weather Kit Update 16 June 2017 — 1 comment

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Zambretti Forecaster

The Zambretti Forecaster is a weather forecasting tool in the form of a circular slide rule introduced in 1920.  It claims to accurately predict near-term weather based on barometric pressure, the trend in the pressure (rising, steady, or falling), and wind direction. It relies on the fundamental meteorology of pressure fronts. Watch any TV weather forecast and …

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Permanent link to this article: https://w4krl.com/zambretti-forecaster/

Sending APRS Analog Telemetry – The basics

The amateur radio Automatic Packet Reporting System (APRS) is typically used for position and weather reporting. It can also handle eight digital and five analog telemetry channels. The IoT Kits© solar-powered weather stations have four APRS analog telemetry channels for LiPo cell voltage, time awake, WiFi signal strength, and light intensity. Four digital channels are used …

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Permanent link to this article: https://w4krl.com/sending-aprs-analog-telemetry-the-basics/

Temporary Station using DIY Solar Shield

It has rained since we arrived at Bethany Beach, Delaware for vacation so it has not been able to test how well the DIY solar radiation shield performs in sunlight. It is hung on a small twig of a tree in the backyard. ThingSpeak feed: https://thingspeak.com/channels/430753 APRS Feed: https://aprs-fi/W4KRL-13

Permanent link to this article: https://w4krl.com/temporary-station-using-diy-solar-shield/

DIY Instrument Shield

An instrument shelter provides a flow of air around weather sensors while protecting them from direct sunlight and rain. Without a shield, the sun can heat the temperature sensor giving a false high-temperature reading. Professional weather stations use a large louvered box called a Stevenson Screen that is built to specific dimensions for standardized weather …

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Permanent link to this article: https://w4krl.com/diy-instrument-shield/

Solar Radiation Shield under test

The D1M-WX1 and D1S-WX1 solar-powered weather stations heat up in direct sunlight giving an incorrectly high-temperature reading. Early results from testing an Acurite solar radiation shield are very good. The shield is available from several online vendors. Check around for a good price as the same item sells for $10 to $60 from different vendors. …

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Permanent link to this article: https://w4krl.com/solar-radiation-shield-under-test/

Important Weather Kit Update 16 June 2017

IMPORTANT NOTE FOR WEATHER STATION BUILDERS Applies only to kits purchased before May 2018 Some builders have noted that the markings on the XH 2-pin connector leads do not conform to the instructions.  It appears that every pair has a different set of markings. Getting the polarity of the connectors wrong, particularly for the LiPo cell …

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Permanent link to this article: https://w4krl.com/important-weather-kit-update-16-june-2017/

Power supply measurements

Most electronic projects operate on low voltage direct current. This is often provided by a USB connection or a battery. There are several possibilities to power a project from the 120 Vac power line. A common way is to use a wall adapter (wall wart) and feed low voltage direct current to your project through a …

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Permanent link to this article: https://w4krl.com/power-supply-measurements/

ThingSpeak Addins

Here is a selection of MATLAB Visualizations tailored to the IoT Kits Weather Stations: ThingSpeak Addins

Permanent link to this article: https://w4krl.com/thingspeak-addins/

HacDC/W3HAC Meeting Presentation Announcement – April 12, 2017 at 7:30 pm

Some of our members recently purchased a solar powered, Arduino programmable, weather station kit from Karl, W4KRL at the Winterfest in Annandale, VA. Due to the popularity of this kit, I invited Karl to come to our next club meeting to give a presentation all about its development, how the station works, etc. Karl has graciously …

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Permanent link to this article: https://w4krl.com/hacdcw3hac-meeting-presentation-announcement-april-12-2017-at-730-pm/