Saturday, January 31, 2015

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


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).

Wednesday, January 28, 2015

QRZ Seeking Experienced Web Programmer. Post #367.

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 experience in both back-end server programming as well as HTML5, javascript, AJAX and a knowledge of modern browser quirks and conventions. Some of the technical skills required for this position include: LAMP programming with the 'P' to include Perl as well as PHP, strong MySQL database skills, and Linux command line skills, to name a few. vBulletin and WordPress familiarity are a plus. Terminal editing skills (such as vi or vim) are required. A deep knowledge of HTML and the DOM are absolutely necessary. As a programmer, you'll be using Javascript, including jQuery, Perl, PHP, and shell scripting.

You also need experience in ham radio. In addition to programming, you will be helping our team support tens of thousands of hams who will be using your work product. Feedback will be instantaneous and your personal gratification will be huge, as will your sense of responsibility towards our 500,000 registered members from around the world. You will need great written communications skills as well as the ability to cheerfully support individual users when problems arise.

Applicants should send their resumes along with an introductory email to: jobs@qrz.com You should include links to websites and/or pages that you've either designed or played a significant role in integrating or developing. The salary offered will depend on your experience.

Not qualified but know someone who is? You can earn a referral bonus if the person you send us gets the job!


Update - Just to clarify: 1) the applicant must be a licensed ham, and 2) the applicant must be proficient in the Perl programming language.
Last edited by AA7BQ; Today at 12:26 AM.
Fred Lloyd, AA7BQ
Publisher, QRZ.COM
aa7bq@qrz.com
"--------------------------------------------------
Please forgive the  inclusion of a non-antenna item in this post.  The opportunity to work for QRZ.com sounds like a win-win for an experienced amateur radio operator with superior web programming skills.  You can work from home, receive a competitive salary, and get immediate feedback from an engaged amateur radio community.  If you're interested in this position, email your resume to:  jobs@qrz.com.  Good luck!

For the latest Amateur Radio news and events, please check out the blog sidebars. These news feeds are update 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 headlines at my news site:  http://kh6jrm.com.

Thanks for joining us today!

Aloha es 73 de Russ (KH6JRM).



'via Blog this'

Monday, January 26, 2015

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


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 are updated daily. You can follow our blog community with a free email subscription or by tapping into the blog RSS feed. Thanks for joining us today! Aloha es 73 de Russ (KH6JRM).

Saturday, January 24, 2015

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

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, battle grounds, and even ground zero. Any one of these is certainly not any other. So it's no darn wonder neophyte amateurs (and a fair amount of old timers) get confused about which ground is which.

There is one type of ground that needs a different name applied to it because everyone seems to have a different opinion of what it is or isn't, and that is Ground Plane! In fact, there is an alternate name which seemingly has disappeared from the amateur lexicon, and that is Image Plane.

A quarter wave vertical antenna is nothing more than half a dipole. This is why it is sometimes referred to as a monopole. We wouldn't erect a dipole with just one leg, so why is it amateurs will erect a quarter wave monopole (vertical) without an adequate Image Plane (ground plane) under it? In part, it's because they're confused by all of the different references to ground (excuse the pun).

Exploring the Image Plane a little deeper; in very simple terms, an Image Plane is the missing half of a dipole. Again, in simple terms, it transforms a monopole into the functional equivalent of a dipole. In a ground mounted monopole, radials provide the Image Plane. On a vehicle, it is the metal mass, plus the capacitive coupling to the surface under it which provide what little Image Plane there is.

If there isn't an adequate Image Plane, losses increase drastically. A full-size, quarter wave monopole, will have an input impedance of roughly 35 ohms. If yours measures 50 ohms, the difference is most likely caused by an inadequate Image Plane. Contrary to popular belief, a ground rod is not an Image Plane. In other words, it isn't a replacement for radials.

Mobile wise, even the largest of vehicles are inadequate in terms of an HF Image Plane. Improper mounting (using mirror brackets for example) just adds insult to injury. Here too, a ground strap is NOT a replacement for the requisite Image Plane.

In a recent post here on eham.net, this very point was exemplified; an HF antenna was mounted on a semi's mirror bracket. One responder suggested adding another ground strap, assumedly to increase the Image Plane, and lower the SWR (one of the reasons for the original post). A link to photos of the responder's own installation was provided as a how-to example. The photos depicted a very good quality HF mobile antenna mounted in the same mirror bracket location, replete with a ground strap. There was no matching device in evidence in any of the photos.

This fact, graphically illustrates the additional losses incurred by this form of mounting. The reason is simply this; in an average mobile installation, the antenna in question will have an input impedance of about 25 ohms. Since the reported SWR was less than 1.2:1, the input impedance was either 41 ohms, or (most likely) 60 ohms. The difference is commonly referred to as ground loss, but it really relates to an inadequate Image Plane under the antenna. In any case, the efficiency stinks, the number of DX contacts notwithstanding!

So, just in case you missed the point, a ground strap (or a ground rod) is not a substitute for an Image Plane/Ground Plane, or what ever you wish to call the missing half of your monopole (vertical). If you think it is, then it is you that's on shaky ground!

Alan, KØBG
www.k0bg.com"
------------------------------------------
Comment:

I ran across this excellent article from Alan Applegate (K0BG) in the 24 January 2015 edition of http://www.eham.com.  Alan does an excellent job of explaining the role of a ground plane (or image plane) in the proper functioning of a vertical antenna.  Without  the missing "half" of a vertical antenna, be it a ground radial system or the metal mass of your vehicle, a vertical antenna becomes a dummy load with most of its radiated power lost to the soil.  Alan adds that a ground strap or a ground rod is not an effective substitute for a ground radial system or a ground plane in your vertical antenna system.  Be careful of antenna claims that violate the laws of physics.  Alan maintains a website that focuses on the installation of mobile antennas.  His articles are well-written and worth every minute you spend reading them.

For the latest Amateur Radio news and events, please check out the blog sidebars. These news feeds are updated frequently.  You can also find more Amateur Radio news at my antenna website--http://kh6jrm.net.

You can follow our blog community with a free email subscription or by tapping into the blog RSS feed.

Thanks for joining us today!

Aloha es 73 de Russ (KH6JRM).



'via Blog this'

Friday, January 23, 2015

Many antennas, multiple benefits. Post #364.

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 'co-located' antennas to significantly reduce relative noise levels inside devices. The second, called distributed-antenna systems (DAS), replaces conventional high-power antennas with strategically placed compact nodes that can split up and transmit signals more efficiently due to improved line-of-sight pathways.
The team's strategy, known as large-scale distributed-antenna systems (L-DAS), seeks to implement DAS with a massive installation base, as seen with MIMO antennas (see image). To realize this goal, however, required a way to evaluate the costs and benefits associated with this innovative infrastructure—simply increasing the number of antenna nodes does not automatically improve wireless network efficiency.
Using a complex computer simulator, the researchers quantified the performances of multi-user L-DAS networks by evaluating their energy efficiencies (that is, the number of bits decoded per joule). According to Joung, modeling energy efficiency is challenging because L-DAS antennas communicate in two ways—wirelessly or through fiber-optic cables—and each channel has different and often proprietary power requirements.
"Another challenge is implementing real-world parameters in the L-DAS network simulator," says Joung. "Many of these parameters have a large dynamic range, from a few quadrillionths of a watt to tens of watts, which can cause precision issues with the computer simulation."
At first glance, the original 'naive' L-DAS setup seemed to have a greater energy consumption than the L-MIMO system with co-located antennas. However, the team identified four key attributes that could dramatically enhance the L-DAS energy efficiency: proper antenna selection, clustering of antennas, pre-coding to improve channel quality, and computerized power control. With these improvements, the L-DAS network outperformed both L-MIMO and DAS technologies.
The group is now looking to the future. "Heterogeneous network (HetNet) architectures that can seamlessly support different 2G, 3G, 4G or WLAN networks are strong candidates for future communication networks," says Joung. "Because L-DAS architecture can be applied to many HetNet applications, this work can help ensure a gentle and smooth replacement of real-life networks with HetNet.""
----------------------------------------------------------
Comment:

Large-scale distributed-antenna systems (L-DAS) may hold the key to deploying Fifth Generation (5G) broadband mobile systems.  Some of this technology could be adopted for Amateur Radio repeaters above 902 MHz.  We should pay attention to this development, because the search for rf spectrum to accommodate broadband signals continues.  The trend of "refarming" frequencies in the 2 GHz and 5 GHz bands has begun in the UK. Some of these frequencies are shared with Amateur Radio, Military, and Public Service agencies.  That process will soon begin in the United States, as Verizon, AT&T, Sprint, and other cellular phone providers look for spectrum to host their new 5G networks.  As the old saying goes, "money talks."  Be prepared to lose a few bands above 1.2 GHz in the years ahead.

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.  For more Amateur Radio news, visit my news site at http://kh6jrm.net.

Thanks for joining us today!

Aloha es 73 de Russ (KH6JRM).



'via Blog this'

Wednesday, January 21, 2015

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


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 get the video. For the latest Amateur Radio news and events, please check out the blog sidebars. These news feeds are updated frequently. You can follow our blog community with a free email subscription or by tapping into the blog RSS feed. For more Amateur Rdio news, visit my news site at http://kh6jrm.net. Thanks for joining us today! Aloha es 73 de Russ (KH6JRM).

Monday, January 19, 2015

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

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 other chapters: VHF- UHF Antennas, TV Antennas, Useful Pieces, Tube Transceiver, Tube Transmitters, Regenerative Receivers, Antenna Tuning Units and so on.

www.antentop.org.

Best Regards and 73.
Igor, va3znw.
Article courtesy of http://www.forums.qrz.com.
------------------------------------------------------
Interesting online antenna magazine created and published by Igor (VA3ZNW). I've noted a few interesting antennas that are worth more investigation, especially those designed for restricted spaces, such as the simple window loop antenna and the "Twin Triangle Antenna for the 10-Meter Band."  Have fun!

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).


'via Blog this'

Sunday, January 18, 2015

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


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).

Saturday, January 17, 2015

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

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 if you have the Internet connection disabled, you are still emanating information that somebody could use to attack your computer or smartphone.”

Zajic demonstrated how this could work by typing a simulated password on one laptop that was not connected to the Internet. On the other side of a wall, a colleague using another disconnected laptop read the password as it was being typed by intercepting the “side-channel” signal produced by the first laptop's keyboard software. The software had been modified to make the characters easier to identify.

Milos Prvulovic, an associate professor in the Georgia Tech School of Computer Science, said, “There is nothing added in the code to raise suspicion. It looks like a correct, but not terribly efficient version of normal keyboard driver software. And in several applications, such as normal spell-checking, grammar-checking and display-updating, the existing software is sufficient for a successful attack.”

Zajic's team is trying to understand why these side channels exist and what can be done to prevent the data leaks. Zajic said, “We are measuring computers and smartphones to identify the parts of the devices that leak the most. That information can guide efforts to redesign them, and on an architectural level, perhaps change the instructions in the software to change the device behavior.

“When you are executing instructions in the processor, you generate a different type of waveform than if you are doing things in memory, and there is interaction between the two,” Zajic added. Zajic, Prvulovic and graduate student Robert Callen have developed a metric known as “signal available to attacker” (SAVAT) which is a measure of the strength of the signal emitted. The largest signals occurred when processors accessed off-chip memory.

Prvulovic said, “It is not really possible to eliminate all side-channel signals. The trick is to make those signals weak, so potential attackers would have to be closer, use larger antennas and utilize time-consuming signal analyses. We have found that some operations are much ‘louder’ than others, so quieting them would make it more difficult for attackers.”

How can you protect yourself from side-channel attacks? Zajic said, “If somebody is putting strange objects near your computer, you certainly should beware. But from the user’s perspective, there is not much they can do right now. Based on our research, we hope to develop something like virus scan software that will look for vulnerability in the code and tell developers what they should update to reduce this vulnerability.”

The Georgia Tech news release did not describe the equipment the researchers used to measure the side-channel emissions, but stronger signals should be able to be picked up by a software defined radio using a repurposed $20 DVB-T USB stick's RealTek RTL2832u. See Software-Defined Radios Help Explore RF Spectrum for details on the RealTek SDR.
---------------------------------------------------
This information from author Doug Lang of "TVTechnology" should interest those of us who use PCs, Macs, or laptops to run logging and DX programs.  Apparently, our digital devices give off enough rf at VHF/UHF frequencies that hackers, equipped with simple equipment, can intercept those weak signals and possibly compromise data on our computers.  There's little that can be done right now, except to keep your anti-virus/malware software up to date and be wary of any strange plug-in devices used near your computer station.  Although the article didn't mention Blue-Tooth devices such as wireless keyboards, they, too, could be susceptible for unwanted monitoring.  Technology is indeed a mixed blessing.

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.  For more Amateur Radio news, please visit my amateur radio news site at http://kh6jrm.net.

Thanks for joining us today!

Aloha es 73 de Russ (KH6JRM).








"



'via Blog this'

Thursday, January 15, 2015

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


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! Aloha es 73 de Russ (KH6JRM).

Monday, January 12, 2015

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


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).

Saturday, January 10, 2015

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


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. These news feeds are updated daily. For more Amateur Radio news, please visit my news site at http://kh6jrm.net. You can follow our blog community with a free email subscription or by tapping into the blog RSS feed. If you can't view the video, please visit the youtube site at: http://youtu.be/3_Z7xEW_d7K. Or you can search for the title directly at "Ham Nation-HF Mobile Antennas." Aloha es 73 de Russ (KH6JRM).

Wednesday, January 7, 2015

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


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 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. For additional Amateur Radio news, visit http://kh6jrm.net. Aloha es 73 de Russ (KH6JRM).

Monday, January 5, 2015

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


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).

Thursday, January 1, 2015

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


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 connected to a 4:1 balun, which used a short length of RG-8X coaxial cable to connect the system to my Drake MN-4. With the ladder line, I can access all amateur radio bands between 40 and 10 meters. The video also contains helpful hints on building shortened dipoles, half-wave dipoles, and dipoles longer than a half wavelength. For the latest in Amateur Radio news and events, please check out the blog sidebars. These news feeds are updated daily. For more Amateur Radio news, you can visit my news site at http://kh6jrm.net. 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).