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H. P. Friedrichs (AC7ZL) Homepage |
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The Radio RoomGetting A Ham License In the late spring of 2003, I decided to finally buckle down and go after a ham license. By mid July, I had passed all four elements and became AC7ZL. As a new ham, I can hardly claim to be an expert, but I can share with you the thought process, materials, and tools I used to prepare for the exams. I was successful, you can be, too! Check out the dummy antenna I built from scraps. It should be good for about 200 watts! Switching power supplies have a lot going for them, but they can be problematic in the Radio Room. Find out why. In the old days, wireless experimenters would wind their coils on Quaker Oats (tm) or Morton Salt (tm) boxes. Follow this link to see the construction of a nifty radio built from more contemporary trash. Build The "Tea Time" Heaphone/Earpiece If you build the CDROM radio, you're going to need some kind of earphone to go with it. Why not make one? Here's how. The BC-348 was a standard-issue receiver on some the most famous bombers in history, including the B-17, the B-24, and the B-29. A chance encounter at a hamfest left one of these treasures in my hands, but could I get it working? If Rigs Could Talk: The TR-VP-213 A military VHF radio travels from France to the deserts of Iraq, through combat, and now to my benchtop. If only rigs could talk! Power For the TR-VP-13: Ideas for Homebrewed, "Military Style" Power Supplies Once I got my TR-VP-13 cabled up and working, I needed a source of power, both for base and mobile operation. I could have slopped something together, but I decided to build something more aesthetic and more elaborate. I used this as an opportunity to explore and express a number ideas related to rugged equipment housings, chassis fabrication, and lead-acid battery packs. Even if you don't have a TR-VP-13, you will find this article interesting. Building The "Sanfordyne" Receiver What do you get when you cross a 1920's era circuit with a 1970's era sitcom and a box full of junk? Fictional character Fred G. Sanford might have answered this way, "A radio, you big dummy!" Build High-Impedance Piezoelectric Heaphones Perfect for crystal radio or simple tube receivers, they're sensitive, they sound good, they're easy to build, and they're dirt cheap. What more could you want? Thoughts On The DoD's "Wearable Power" Contest The Department of Defense Research and Engineering is conducting a contest to develop a lightweight, "wearable" power unit to provide electricty for the ever-increasing variety of electronic gadgets that modern soldiers carry with them. Here are some thoughts on the contest, the challenges implied, and what kind of technology might actually do the job. Barefoot On The Beach: QRP In A Tropical Paradise In the spring of 2007, I had the opportunity to visit San Juan in Puerto Rico. The trip was an adventure-- all the more because I had decided to bring some radio equipment with me. Read about it here! Cold War QRP: A Case of Discone Fever? Introduced in 1959, the Titan missile was part of the war machinery that would help to assure a peaceful, if uneasy, balance between superpowers for almost four decades. The silos in which these weapons were based were slated to be decomissioned in the 1980's, but one remains intact and can now be visited by the general public. Even better, the site offers a special treat for those of us with an interest in radio! |