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Showing posts from November, 2014

Simple Ham Radio Antennas: How to make a NVIS HF Radio Antenna. Post #329

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. Here's a very simple, basic NVIS (near vertical incident skywave) antenna for portable or emergency use. Most of the parts can be found in your shack or at the nearest hardware or home improvement outlet. Although there are losses in the system (primarily from the coax), the antenna does well, giving good local coverage out to 200- 300 miles/320 - 480 kilometers, depending on the band for which the antenna was designed. If you want to build a more permanent NVIS antenna for various local or regional nets, I would recommend feeding the antenna with 450-ohm ladder line into a balanced tuner or through a 4:1 balun and then into a "regular" tuner. With this arrangement, you can get multiband coverage with reduced losses and manageable SWR readings. Plans for this antenna can be found here: http://home.centurytel.net/w9wis/NVIS. For the latest in Amateur Radio news and events, please check out the blog sidebars. These news feeds are updated daily. You can follow…

Simple Ham Radio Antennas: Basic Antenna Fundamentals (How a Dipole Works). Post #328.

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A clear, concise explanation of how a dipole antenna works. This video is good for basic amateur radio classes or for self-study and review. Dan Vanevenhoven (N9LVS) has done an excellent job of unraveling the "secrets" of a simple dipole antenna. For the latest Amateur Radio news and events, please check out the blog sidebars. These news feeds are updated daily. You can follow our blog community with a free email subscription or by tapping into the blog RSS feed. Aloha es 73 de Russ (KH6JRM).

NASA opens Cube Quest Challenge for largest-ever prize of $5 million. Post #327.

NASA opens Cube Quest Challenge for largest-ever prize of $5 million
. How would you like to win a share of $5 million? You can if you join a team entered in the NASA CubeSatQuest Challenge. The purpose of the challenge is "to develop new technology that will advance the state of the art of CubeSats and demonstrate their capabilities as viable deep space explorers." For details, visit http://www.nasa.gov/cubequest. This is a golden opportunity to advance the cause of space exploration while at the same time solidifying  your financial future. Good luck! For the latest in Amateur Radio news and events, please checkout the blog sidebars. These news feeds are updated daily. You can follow our blog community with a free email subscription or by tapping into the blog RSS feed. Until next time, Aloha es 73 de Russ (KH6JRM).

Simple Ham Radio Antennas: A Multiband Loop Antenna, 80 meters through 10 meters. Post #326.

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An excellent video guide to building, erecting, and maintaining a simple 80-10 meter loop antenna. Lynn (NG9D) covers the basics in a short, well-produced video that can be applied to many home situations. With careful attention to detail and choice of wire, the antenna is fairly stealthy--something of concern to many of us "penned in" by neighbors and nearby buildings. Lynn uses commonly available RG-58 and RG-59 for the feedline. If you can't find two tall supports, try designing the antenna as a delta loop. A tall tree limb or a telescoping fiberglass mast could serve as the apex of the loop. If space is a concern, you could build the loop for 40-10 meter coverage. If you're worried about high SWR on the coax, feed the loop in a bottom corner with 450-ohm ladder line. Run the ladder line to a balanced antenna tuner or to a 4:1 balun. Fifty-ohm coax would then run from the balun to your antenna transmatch (tuner) and onto your rig. Either way, the design …

Simple Ham Radio Antennas--A Simple Wire Antenna Tuner. Post #325.

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If you're looking for a basic, simple antenna transmatch ("tuner") for that "long wire" or random length wire connecting your transceiver to the "ether", you've found the right place. Stan Gibilisco (W1CV) provides an easy to understand tutorial on how to build a random wire antenna "tuner" for your QTH or for that portable operation on the weekends. The "tuner" can also work with end-fed half-wave antennas. It's important to have a good ground or radial system with this type of antenna. I built a similar antenna transmatch during my Novice License years (1977-1979) and got a lot of enjoyment and contacts with it. As I recall, I was using a Heathkit HW-101 transceiver attached to a 100-ft/30.48 meters wire strung up in a tall Norfolk Pine Tree. My radial system consisted of an 8-ft/2.43 meters copper ground rod with four, 33-ft/10.06 meters radial wires attached and buried about 1 inch/2.54 cm below the lawn. My feed …

Ham Radio Tutorial - Intro To The HF Bands. Post #324

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While this excellent tutorial by N7TFP is aimed at newly licensed General and Amateur Extra Class licensees, it contains valuable refresher material for those of us who've been out of the hobby for a while and need to catch up on some basic principles. Much of the tutorial is spent on explaining the differences between VHF and HF operations, including propagation, antennas, frequencies, and modes available for the new General and Amateur Extra Class license holders. The discussion centers around two popular amateur HF bands--80 and 20 meters. The conversation and discussion of these bands is brief, but unhurried. This would be a nice video for "elmers" (mentors) helping newly licensed amateurs get on the air. For the latest in Amateur Radio news and events, please check out the blog sidebars. These news feeds are updated daily. Aloha es 73 de Russ (KH6JRM).

Simple Ham Radio Antennas: A 12 meter Pepsi can vertical antenna. Post #323.

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Great video by Dave Turlock! It's time to recycle those aluminum soft drink cans and turn them into functioning amateur radio antennas. Dave says this antenna can be used on 10 meters, 11 meters (CB), and even the 15 meter amateur radio bands. With the price of copper tubing going higher every day, this economical approach to a metal vertical makes a lot of sense. I would be concerned, however, in making sure the cans were joined together tightly to maintain integrity throughout the length of the antenna. Some of the paint would have to be removed from the joined sections to make sure aluminum met aluminum along the entire length of the vertical. "QST" published a story in the late 1950s about a ham who built a beautiful "beer can" antenna for 40 meters, complete with guylines and an extensive ground system. That antenna worked very well. Although I pride myself in making antennas out of the scrap wire and metal lying about my shack, I've never tried…

Simple Ham Radio Antennas: A 2 meter VHF Handheld Ground Plane or Tiger Tail Antenna. Post #322.

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Most of the "rubber duckie" antennas that come with 2 meter handheld transceivers leave a lot to be desired. You can get better performance out of your HT by either buying a commercially-made telescoping 1/2 wave or 5/8 wave metal rod antenna or by simply adding the missing half of the antenna by attaching a "tiger tail" counterpoise wire to the base of your stock "rubber duckie" antenna. This video does a fairly good job of describing how to make an inexpensive "tiger tail" that helps your "rubbie duckie" antenna perform better. I made one of these "tiger tails" for my old Kenwood TH-21A HT. When I'm in Hilo, Hawaii, I can now reach all East Hawaii repeaters with the low power setting (.1 of a watt) on the old Kenwood HT. I soldered a ring connector to a 19-inch/48.26 cm length of #22 AWG hookup wire and attached the ring to the base of the screw-in "rubber duckie" antenna. With the "tiger tail"…

Simple Ham Radio Antennas: A Portable HF Ham Radio Antenna. Post # 321.

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Helpful video by Dave (W0ZF) on how to build a simple portable antenna for the amateur radio bands.  The antenna, whether it be for 20 meters, or some other band , is simple, inexpensive, and easy to build.  I've built several 20 and 40 meter versions following Dave's general example.  All have worked very well with powers in the QRP range (1-10 watts).  I got my speaker wire from Radio Shack, the pole was a telescoping fiberglass fishing pole I found at The Sports Authority, and the nylon string, insulators, and coax I had around the shack.  Although you can get by with just a vertical element and a "counterpoise" wire lying on the ground, you will get better performance if you use several elevated radials below the base of the vertical element.  I have a 40 meter version of Dave's antenna which is erected in the backyard of my one-acre property.  I used a 33-ft/10.06 meters MFJ telescoping fiberglass pole, 32-ft/9.75 meters of #18 gauge speaker wire from Radio…

Simple Ham Radio Antennas: The End Fed Halfwave Vertical. Post #320.

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A curiously fascinating "shoot out" between a 135-ft/41.15 meters OCF dipole antenna mounted 40-ft/12.19 meters above ground versus a 31-ft/9.45 meters halfwave vertical sitting on an apartment deck. The empirical "test" of Tony's (W1ZMB) OCF dipole and Stan's (WB2LQF) halfwave vertical shows that the simple vertical halfwave antenna performs almost as well as the OCF. The halfwave vertical has a few advantages over its fully extended OCF dipole cousin: It has a high feed point impedance which makes it efficient; it's simple to build and relatively inexpensive to assemble; it's versatile for both home and portable use; it doesn't require a ground radial system; and it can be used in a variety of configurations--sloper, inverted "L", or horizontal. All you need is a 31 ft/9.45 meters telescoping fiberglass pole (Jackite or MFJ), a homebrewed 9:1 balun, enough wire for a half wavelength vertical at your favorite frequency, a convenien…

The Heathkit AT-1 Amateur Radio Transmitter. Post #319.

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It's time for a little nostalgia, thanks to the Heathkit AT-1 Amateur Radio Transmitter. Jeff Tranter does an excellent job of explaining how the AT-1 works and demonstrates some of its capabilities. This 3-tube transmitter, coupled with a simple dipole or vertical antenna, gave newly licensed novice operators many hours of enjoyable contacts. The rig was well-shielded and offered fairly good TVI suppression. Once a novice passed the General License Exam, he/she could plug in a VFO and an AM modulator. I've only used an AT-1 once in my 37-year amateur radio "career"-a rig belonging to a fellow amateur operator on Hawaii Island back in 1977. Even in that year, the AT-1 was well out of production, having been originally introduced around 1953. As Jeff warns all would-be restorers, special care must be taken around this rig, since high voltage may be present on the chassis. Tranter recommends removing the old 2-prong cord and replacing it with the 3-prong plug …

Simple Ham Radio Antennas: A Random Wire Solution for an "interior shack". Post #318.

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Here's another great antenna idea for those amateur radio operators limited by HOAs and CC & Rs.  Stan's "stealth antenna" is simple, cheap, and easily deployed for both home and portable use. When I first became a novice licensee back in 1977, I used a similar antenna at a rented home near the Honokaa High School campus. The community was located along the Hamakua Coast of Hawaii Island and had an excellent clear water shot to the mainland United States and Europe. The only difficulty I had in those days was the lack of a decent back yard to support a dipole or a radial system for a vertical antenna. I did have a tall Norfolk Pine Tree in the back yard which I "recruited" to support the end of my random length wire. I used an 85-ft/25.91 meters length of #22 AWG wire for the radiating element and a 17-ft/5.18 meters length of #22 AWG wire for the counterpoise. My crude antenna was a variation of the once popular "Zepp" antenna used on the…