Dan Koellen AI6XG6 days ago6 minReactive Component Measurement With the NanoVNAExploration of using the nanoVNA to measure inductance and capacitance at frequency of use.
Dan Koellen AI6XGMar 211 minToroid Transformers - How Hot Will It Get?There are a number of factors in choosing a toroid for a RF transformer. While one may model electrical performance, calculate predicted...
Dan Koellen AI6XGJul 30, 20212 minLeg Benchmark W7Y/EW-017 Activation - An Alternative Route From the WestPole Mountain From My Operating Position Summit Trip Summary Distance: ~ 2.6 mi one way Transport: Hiking Elevation Gain: ~500 feet...
Dan Koellen AI6XGJul 20, 20219 minElectrostatic Discharge (ESD), Does it Matter for Makers and Hackers?Electrostatic Discharge (ESD) is a subject that can inspire a lot of discussion, head shaking and some misunderstanding. ESD damaging...
Dan Koellen AI6XGJun 16, 202113 minDon't Fear the Smith ChartLike many radio amateurs I was initially intimidated by the Smith chart. Transmission line and antenna theory, unfamiliar terms and...
Dan Koellen AI6XGApr 26, 20213 minSchallenberger Ridge W6/NS-213 Activation - An Alternative RouteA different approach to Schallenberger Ridge from the west. A nice hike through historic train tunnels.
Dan Koellen AI6XGApr 25, 20219 minHow I Killed a MicrocontrollerThis blog outlines the steps taken to determine why a microcontroller no longer works, and the journey to find the damage on the chip.
Dan Koellen AI6XGJan 25, 20212 minThe Digi-Disco, a 1970's Light ControllerThis is a light system that I designed and built in 1978 to control large flood lights of different colors, synchronized to disco music...
Dan Koellen AI6XGJan 25, 20211 minHeathkit IT-28 Capacitor CheckerAfter building the Pico C-Super capacitor tester that was published in Elektor Magazine I decided to revive an old Heathkit IT-28...
Dan Koellen AI6XGDec 15, 20202 minMount Rose W7N/WC-001 ActivationLake Tahoe and Tamarack Peak From Mount Rose Summit Trip Summary Distance: ~ 4.9 mi one way Transport: Hiking Elevation Gain: ~1800...
Dan Koellen AI6XGDec 13, 20202 minTamarack Peak W7N/WC-003 ActivationLake Tahoe From Tamarack Peak Summit Trip Summary Distance: ~ 1.3 mi one way Transport: Hiking Elevation Gain: ~960 feet Time: ~ 0.75...
Dan Koellen AI6XGDec 10, 20203 minMount Houghton W7N/WC-002 ActivationOperating Position on Mount Houghton, Mount Rose W7N/WC-001 in Background Summit Trip Summary Distance: ~ 4.8 mi one way Transport: ...
Dan Koellen AI6XGDec 3, 20202 minScott Peak W6/NS-153 ActivationOperating Position on Scott Peak Summit Trip Summary Distance: ~ 4.2 mi one way Transport: Hiking Elevation Gain: ~1700 feet Time: ~2...
Dan Koellen AI6XGNov 29, 20205 minGranite Chief W6/NS-115 ActivationOperating Position on Granite Chief Summit Trip Summary Distance: ~ 4.6 mi one way Transport: Hiking Elevation Gain: 2748 feet Time:...
Dan Koellen AI6XGNov 23, 20201 minWishing You a Very Random ChristmasBeing the holiday season I decided to post this article from the December 2014 issue of Nuts & Volts magazine www.nutsvolts.com that I...
Dan Koellen AI6XGOct 4, 20208 minTrapped 20/30/40 Meter EFHW AntennaAn End Fed Half Wave (EFHW) antenna for operation on 20, 30 and 40 meters was built for SOTA operation. By using traps, the antenna...
Dan Koellen AI6XGJun 29, 20207 minBig Font Clock Update: Dimmer-Interface PCB and Setup Instructions.A prior post described the development and build of a clock to display time and date for UTC and Local. The clock characters are large,...
Dan Koellen AI6XGJun 6, 20204 minEnd Fed Half Wave Antennas: More About the Primary CapacitorI recently posted a blog claiming that a capacitor in the primary of the matching transformer is not needed for end fed half wave (EFHW)...
Dan Koellen AI6XGMay 27, 20203 minEnd Fed Half Wave Antennas: Is a Primary Capacitor Really Needed?In my research on End Fed Half Wave (EFHW) antennas I found that nearly all have a capacitor in the primary (rig) side of the transformer....
Dan Koellen AI6XGApr 5, 20203 minAuto Run for your Raspberry Pi - how to have your Rpi boot up in the desired configuration.The Raspberry Pi (Rpi) is a great single board computer (SBC) that can be used in many projects and comes in different configurations. I...