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{ Category Archives } Off Grid

The technologies you need when you are not connected to commercial power sources

Air conditioning, humidity, condensate and Summertime

Having to use the shop vac to get a few gallons of water out of the ductwork on a regular basis was an indication of a problem. Where does it come from? I used Calculate Temperature, Dewpoint, or Relative Humidity to see how humidity changes with temperature. 90F at 10% humidity is a 26F dew […]

Choice: ‘Zombie Apocalypse’ or ‘Hello Kitty’ as your AR-15 theme?

He says that the AR-15 is more than a gun, it’s a gadget — and that is why it is so popular. “fringe groups don’t adequately explain the roughly 5 million “black rifles” (as fans of the gun tend to call it) that are now in the hands of the public. No, the real secret […]

Is methane poisonous?

An old Perry Mason show, the Case of the Bogus Books (first aired 9-27-62), has a murder caused by natural gas or methane. It seems the criminal turned off the gas to kill the pilot light and then turned the gas on again so it would kill the occupant of the room as gas from […]

EMR fear and fanatacism

The FCC now requires careful consideration of exposure to electromagnetic fields by radio amateurs. The cell phone radiation fears come and go. Harriet Hall has a rundown on the Nonsense about the Health Effects of Electromagnetic Radiation citing Helke Ferrie and “dirty electricity.” “I could go on to deconstruct every paragraph of Ferrie’s article, but […]

What glue to use?

Adhesives are becoming every more important in fastening things together. They are often stronger than mechanical fasteners like screws, nails, bolts, or rivets. The problem is in choosing the right adhesive for the job at hand. Karl Chwe found that construction adhesive has been the best shoe repair he’s found. He discusses the options in […]

History lesson from the Roman Army

“Hans Delbruck said of the eventual Roman triumph over the Greeks, “All the differences between the Greek and Roman military systems can be traced back to the difference in discipline.”[16] It was this discipline that allowed the Romans with first a citizen army, and then a professional army, to secure the borders of a new […]

Personal defense pistol caliber

Strategy Page describes Why the .45 Matters but misses one critical fact. The military is restricted by the Geneva conventions which allow only ball ammunition. Civilian self defense is a different matter than military action and that means that using the military experience needs to be properly qualified. “A smaller, faster bullet has a tendency […]

History of radio receiver designs

The preppers have The Evolution of Radio Technology, Part 1, by Roger R. as a good summary of the development of the radio receiver. “The primary steps or changes in the design of radio receiver construction are, the “crystal set” or Passive Tuned-Radio-Frequency (TRF) receiver, the Active TRF, or ‘straight’, receiver, the Regenerative (‘regen’ or […]

Discovery of the elements – timeline

There is an electropaedia with a tabular timeline for the discovery of the elements. This has fascinated me since I investigated the introductory physical science course developed by the PSSC. That course traveled the history of separating things to learn about molecules and atoms and their relative sizes. You can see the impact of technology […]

What about just sitting on the beach?

Mark Roberts describes a conundrum some face when laid off work or retiring in Creation, Contentment, and Work. Human beings are not simply to sit on a beach and enjoy the beauty of creation. Nor are they simply to sit in a cathedral and enjoy the beauty of God. Rather, they are to be actively […]