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Ipinapakita ang mga post mula sa Oktubre, 2020
Imahe
Ks*bCHTRa5&+ciV Bob Brooks KB6VAT and the Japanese Zero   A long time ago, Bob Brooks KB6VAT (SK) showed me a piece of composite board consisting of balsa core and some other materials sandwiched by aluminum sheets. He told me it was part of a Japanese Zero. Bob sold his home in the states and with the proceeds bought materials and plans to build his new dream home, a catamaran that was later to be christened the "Cat House". The hull of his cat was to made of fiberglass composite with a balsa core. Bob was quite a guy and he made club ragchews on our VHF frequency very interesting... Never a dull moment. He is from Arcadia, CA. (he said there are many "Arcadias" in the states, HIHI) He said Arcadia was often used as a location for movies. He also worked at the Arcadia Police Department maintaining communication electronics, and as such became a member of the IPA (International Police Association). One time he mentioned that all single engine aircraft had a l

Do your power supplies leak?

Imahe
  Do your p ower supplies leak? "Feet" for my Meanwell power supply. the are surplus pi zero case covers. A good test for leakage in a switching power supply (with no ground wire connected) is to hold the aluminum case with one hand and touching your bare foot on a concrete floor. If you get even the slightest tingling effect, it means there is some AC leakage in your power supply. This goes for switching as well as for linear power supplies. Excessive leakage may cause serious shock specially if you touch two ungrounded cases of equipment connected to two different supplies which have leakage. (no ground pin on the plug or no connection to house electrical ground). This has happened once in our club radio shack. I had told the owner of an Astron linear power supply that one Astron transformer has to be rewound because I could sense the leakage with my hand. He forgot to have it done and a year later a visiting foreign ham got "shocked" when fuses blew when connec