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Showing posts from January, 2015

Simple Ham Radio Antennas: Full-Wave Loop Antenna. Post #368.

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Nice, easy to understand tutorial on Full-Wave Loops antennas from Stan Gibilisco (W1GV). I've used full-wave loop antennas for many years and have found them to be simple, effective, and efficient. Full 80-10 meter coverage can be gained if you design your full-wave loop for 80 meters and use 450 ohm ladder line as your feed line. The ladder line then goes into a balanced tuner, which is connected to your rig by a short length of coaxial cable. If you don't have a balanced tuner, you can connect the ladder line to a 4:1 balun and use a short piece of coaxial cable to connect the balun to your tuner. You can use a variety of shapes for your full-wave loop, with the square and delta loop being popular options. 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).
Related ar…

QRZ Seeking Experienced Web Programmer. Post #367.

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QRZ Seeking Experienced Web Programmer: " QRZ Seeking Experienced Web Programmer
QRZ is looking for a skilled, experienced web programmer to join our team and become a part of ham radio history. QRZ is an internet-based virtual company and so this is an opportunity for a work-at-home position. It doesn't matter where you live so long as you have a great internet connection and can interact with other team members who are on the Mountain Standard Time schedule. This is a salaried, full time position that offers competitive pay, benefits, vacation as well as sick leave. You are free to move about the country and connect in from exotic places while you work. Like I said, it doesn't matter where you are located, or even if you're mobile, so long as you are able to login, work, make deadlines, and have frequent interaction with the rest of the team on Skype.

QRZ's technical infrastructure is cloud-based using industry standard LAMP practices. You'll need experienc…

Simple Ham Radio Antennas: Ham Radio 10 Meter Ground Plane Antenna. Post #366

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A nice weekend construction project from Dave Tadlock (KD0ZZ).The 10 meter band is one of my favorite hangouts. You never know when propagation will smile on you and reward you with a nice DX contact. Although Dave's antenna is not a "ground plane" antenna in the purist sense (a ground plane is always elevated to decouple the radials from the actual ground and, thereby, reduce ground loses), the antenna is well designed and will give you many hours of fun on a band which exhibits both HF and VHF characteristics. You could also modify a standard CB (11 meter) stainless steel whip (102 inches/259.08 cm), add four elevated radials, and raise the bottom of the whip to a height of 16 to 20-feet/4.87-6.09 meters above ground level. Good results can be obtained with Dave's or my somewhat cruder project. The idea is to build your own antenna and experiment. Have fun! For the latest Amateur Radio news and events, please check out the blog sidebars. These news feeds a…

Simple Ham Radio Antennas: Let's Do Ground Planes Again. Post #365.

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Let's Do Ground Planes Again: "Let's Do Ground Planes Again

from Alan Applegate, K0BG on January 24, 2015."Editor's Note: Due to the popularity of some of eHam's older articles, many of which you may not have read, the eHam.net team has decided to rerun some of the best articles that we have received since eHam's inception. These articles will be reprinted to add to the quality of eHam's content and in a show of appreciation to the authors of these articles." This article was originally published on: 07/02/2007






Let's Do Ground Planes Again

The Spanish language has a whole bunch of words which mean hot, while English gropes around with about two or three. Spanish gets a little fuzzier with the word Ground, but not nearly as much as English. We have the ground we walk on, hollowed ground, DC grounds, AC grounds, RF grounds, and grounds for divorce! We also have polo grounds, capital grounds, football grounds, common grounds, proving grounds, ba…

Many antennas, multiple benefits. Post #364.

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Many antennas, multiple benefits: "Many antennas, multiple benefits",
Jan 21, 2015

By combining large distributions of compact antenna nodes with fast fiber optic communication, researchers have developed a new wireless infrastructure ready for intense future demands. Credit: A*A*STAR Institute for Infocomm Research
A concept that balances large-scale installations of low-cost and low-power antennas to boost cellular coverage in difficult environments will also provide better connectivity to more users. Developed by A*STAR, this new architecture for wireless communications can help service providers meet growing demands for increased network capacity and improved energy efficiency.

Jingon Joung, Yeow Chia and Sumei Sun from the A*STAR Institute for Infocomm Research in Singapore sought to combine two state-of-the-art wireless technologies into a novel type of antenna system. The first technology, known as large-scale multiple-input multiple-output (L-MIMO), uses numerous …

Simple Ham Radio Antennas: Broad Bandwidth Ham Radio Antenna Demonstration. Post #363.

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A fun and not necessarily "scientific" demonstration on how larger diameter radiating elements of an antenna will provide wider bandwidth coverage. To keep weight and structure support under control, Larry (WD0AKX) chose the 2-meter band for his fascinating experiment. Using a frequency of 147.861 MHz as the design frequency, Larry makes antenna elements ranging from 1/16-inch to 3-inches in diameter to test his theory. His rudimentary tests confirm that larger diameter antenna elements do widen the bandwidth a bit on 2-meters. The same principle applies to HF operation, where classic "cage" dipoles, folded dipoles made from 300-ohm tv ribbon line, and fan dipoles often are used to broaden bandwidth. Overall, the video is well done and shows how simple antennas can be improved with just a few simple tools and instruments. If the video doesn't cue up immediately, direct your browser to: http://youtu.be/sLHOIG7O7w. You can also enter the title directly to ge…

Simple Ham Radio Antennas: Free online magazine Antentop 01- 2014 is ready. Post #362.

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Free online magazine Antentop 01- 2014 is ready.: " Free online magazine Antentop 01- 2014 is ready.
Hi.
Free online magazine Antentop 01- 2014 is ready.
It contains 41+ topics, including:
Antenna Theory: Linear Array Theory- Part II;
HF- Antenna Practice: 44 Feet Dipole. Where is theTruth?: Lawn Antenna: Buried Antennas for  Emergency Communications: Simple Broadband Antenna for the 40- meter Band: Directional Antenna UA6AGWV. 7.00: Antenna UA6AGW in Experimenters byRU1OZ : Antenna UA6AGW V.40.20:Field Antenna UA6AGW V.40.21: Shortened Antenna G5RV for 14- 50- MHz Bands: Shortened Dipole Balcony Antenna for the 20- meter Band: Simple Window Loop Antenna: Simple Folded Dipole Antenna for the 20- meter Band: Simple Wire Antenna for All HF- Bands: Twin Triangle Antenna for the 10- meter Band: Compact Twin Delta Antenna for the 80- and 40- meter Bands: Delta Antenna for 80-. 40-, 20- and 15- meter Bands:Windom UA6CA for 80-, 40-, 20- and 10- meter Bands: Air Plane HF Antennas.
And oth…

Simple Ham Radio Antennas: Ham Radio Tutorial - HF Radio Wave Propogation. Post #361.

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Part one of a two-part series on HF propagation. Although I've been unable to find Tyler's (N7TFP) second chapter of the series, the first video is more than adequate in explaining the basic theory behind HF propagation. This tutorial is well-produced, easy to understand, and informative. This video would make great supplementary study material for those taking a Technician Class Amateur Radio Course. Perhaps, someone has found the second part of the series...I surely hope so, because the first video is especially well done. For the latest in 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. You can find more Amateur Radio happenings by visiting my news site at http://kh6jrm.net. Thanks for joining us today! Aloha es 73 de Russ (KH6JRM).

TVTechnology: Low-Level RF Signals Allow Hackers to Grab Data From Laptops. Post #360

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TVTechnology: Low-Level RF Signals Allow Hackers to Grab Data From Laptops: "Low-Level RF Signals Allow Hackers to Grab Data From Laptops. No Wi-Fi required. As anyone who has tried to use a portable AM or shortwave radio near a computer knows, computers emit a variety of RF signals over a wide range of frequencies. The emissions can extend into the VHF bands. Although these emissions are considered noise or interference, the reality is they contain information about what's happening inside the computer.

Researchers at the George Institute of Technology are studying these emissions to help hardware and software designers develop strategies to plug these RF data leaks. Alenka Zajic, an assistant professor in Georgia Tech’s School of Electrical and Computer Engineering, explains, “People are focused on security for the Internet and on the wireless communication side, but we are concerned with what can be learned from your computer without it intentionally sending anything. Even…

Simple Ham Radio Antennas: Multiband HF Stealth Vertical Antenna Run-through. Post #359

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A very simple, stealth antenna that produces good results without being seen by nosey neighbors. Basically, Tony has built a 3-band vertical with all elements connected to a single SO-239 connector and a radial ground system. Tony's antenna resembles a vertical fan dipole, with the radial system supplying the "missing half" of the antenna. I've built several antennas following Tony's basic design. They all work very well and no one in the neighborhood knows the antennas are there. Of course, there are tradeoffs. This antenna won't bust a pileup or get you 59+ reports all the time. But it does work. And, sometimes that's all you need to get on the air without being noticed by the HOA/CC&R "police." Good luck! For the latest Amateur Radio news and events, please check out the blog sidebars. These news feeds are updated daily. For more Amateur Radio news, please visit my news site at http://kh6jrm.net. Thanks for joining us today! …

How to Work Amateur Ham Radio Satellite w Baofeng UV5R MFJ on Saudisat S...Post #358

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Working satellites with a simple handheld VHF/UHF transceiver is loads of fun, especially if you can do it without spending a lot of money. David Mercado (KK4MND) shows how he made contact with the popular SaudiSat SO-50 with just an inexpensive Baofeng UV5R and a MFJ Dual Band Antenna from Amazon. You don't need a lot of space to set up a temporary antenna for these low earth orbit birds. Have fun! For the latest in Amateur Radio news and events, please visit 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. For more Amateur Radio news, please visit my news site at http://kh6jrm.net. Thanks for joining me today! Aloha es 73 de Russ (KH6JRM).
Related articlesGlobal Hourly HF Propagation MapsThe February Issue of Digital QST is Now AvailableLoRa - low cost long distance telemetryGraphene-Based Nano-Antennas May Enable Networks of Tiny Machines - Department of Electr…

Simple Ham Radio Antennas: Ham Nation - HF Mobile Antennas. Post #357

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Nicely paced video from author/instructor Gordon West (WB6NOA) on mobile HF antennas. Gordon does a good job of covering the basics of mobile operations, including the type of HF mobile antennas available, the importance of grounding, and how to get a match close to 50 ohms for your rig. Much of what Gordon discusses here can be applied to other compromised antenna situations, such as HOAs and CC&Rs. If you live in this type of situation, some of the mobile HF tips suggested by Mr. West could give you a way of getting on the air with a good signal and still remain mostly hidden. In fact, you may want to design your home antenna around a mobile antenna. Some of the newer mobile antenna designs are quite stealthy and put out a good signal. Perhaps a "Little Tar-Heal Antenna" or an ATAS-120 would get you on the air with a minimum of space and nosey neighbors. It's worth a try. For the latest Amateur Radio news and events, please check out the blog sidebars. Thes…

Demonstration of the Knight T-60, and Heathkit VFO VF 1 Power Supply. Post #356.

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One of the popular transmitters used by newly minted novice amateur radio operators in the 1960s and 1970s was the Knight Kit T-60. It was fairly cheap ($49.95) and could be operated in either AM phone or CW. As I remember, the T-60 had four tubes--6HF8 (oscillator), 6DQ6 (power amplifier), a 6DR7, and a 12AX7. The rig had a bad chirp on CW, most likely caused by improper loading of the plate circuit. That defect resulted in many FCC pink tickets and OO reports for new licensees. Although I never owned one, I used the rig a few times during field days and other portable operations. When I was first licensed as a novice in 1977, I was offered an old Heathkit HW-101 and that pushed the T-60 project out the door. This video does a good job of describing the functions and quirks of this early ham radio transmitter. Here are two places where you can find out more about this "classic" novice rig: http://www.ehmam.net (07 January 2015) and w9zt.webs.com. For the latest Ama…

Simple Ham Radio Antennas: Ham Radio Xmas Story - ALEXLOOP! Post #355.

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The ALEXLOOP antenna is a well-made HF portable antenna designed for emergency and portable use. The ALEXLOOP Walk ham radio antenna is well-respected by the QRP community and is gaining in popularity as an emergency antenna for home use. This video by Randall (N4SAX) is hillarious and a bit "off center", but the message is clear: The ALEXLOOP magnetic portable antenna is a real gem worth keeping. Although I prefer to build my own wire antennas, I may deviate from that principle and buy one of these "effective solutions" for my own portable use. Great video! For the latest Amateur Radio news and events, please check out the blog sidebar. 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. For more Amateur Radio news, please visit my news site at http://kh6jrm.net. Aloha es 73 de Russ (KH6JRM).

Simple Ham Radio Antennas: Antenna-Theory.com Presents: The Dipole Antenna. Post #354

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For my first project of the New Year, I decided to build a simple dipole antenna that could be used at the home QTH or at some portable location, such as a public park or a club Field Day. Although, I've built many dipole antennas, I felt a review of some basic antenna theory would "clear out some of the rust" incurred over the New Year's Eve celebration. I found this interesting video antenna tutorial from http://www.antenna-theory.com. The instruction was very clear and the basic forumlas were explained in plain language. This video would make good supplementary study material for those desiring an amateur radio license. In the end, I opted for a simple 40/15 meter inverted vee supported by a 33 foot/10.06 meters telescoping fiberglass mast. My feedline was some RG-8X I had stored in the garage of my vacation home in the Puna District of Hawaii Island. The antenna works very well on 40 and 15 meters. I have also fed the antenna with 450-ohm ladder line con…