Amateur Radio
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The ARRL will host a 2015 Hurricane Season webinar Monday, July 20, getting under way at 8 PM EDT (July 21, 0000 UTC). The approximately 90-minute session will address the role of Amateur Radio during the 2015 Hurricane Season. Anyone interested in hurricane preparedness and response is invited to attendthis online presentation. Topics will include a meteorological overview of the upcoming season; Amateur Radio station WX4NHC at the National Hurricane Center: Who We Are and What We Do; ARRL Media and Public Relations; the Hurricane Watch Net (HWN); theVoIP Hurricane Net, and ARRL coordination and interface. The program will include presentations by representatives of the National Hurricane Center and WX4NHC, the VoIP Hurricane Net, the HWN, the Canadian Hurricane Centre, and the ARRL. Webinar registration is open to all, but should be of particular interest to radio amateurs in hurricane-prone areas. The webinar will conclude with a Q&A session. Register online. — Thanks to Mike Corey, KI1U, ARRL Emergency Preparedness Manager
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The FCC has decided to drop all fees for issuing vanity call signs to hams. In a ruling issued on May 21, the Commission explained that the costs of processing the payments and issuing refunds to amateurs whose requests cannot be met exceed the revenue from vanity call fees, currently $21.40 for a 10-year license term. According to the ARRL, the change will not take effect until after the FCC has formally notified Congress of the move, which in the halls of federal bureaucracy takes at least 90 days. So the earliest effective date would be late August to early September. If you’re planning to apply for or renew a vanity call in that timeframe, and won’t risk having your license expire in the interim, then it might be best to wait, since the FCC also says it will not refund fees paid prior to the formal elimination.
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May 19, 2015This is my next Antenna Project Typically the reflector is 5% longer and the director 5% shorter than the driven element. By spacing elements about 0.15 to 0.25 wavelengths from each other you end up with a beam antenna with about 7dB of gain. (According to the author) To figure out the correct length of the driven element the following simple formula for a half-wave antenna above 30 MHz is used : Length in feet = 475 / Frequency (MHz) Construction : 3/4 inch PVC plumber’s pipe is recommended for the supports. Two 18 inch pieces become the boom where the elements are installed. A 36 inch piece is used for the mast. (Although not shown in the original drawing, it is assumed the the T is about 2 inches long.) The boom and mast pieces are held together with a PVC T joint. Three small holes are drilled in the T as well as the boom and mast pieces. (Look at the T in the drawing for the small black dots. These are the locations of the screws).The boom and mast are inserted into the T and rotated until the holes are aligned. Then the boom is secured with screws…or you may use bolts also if you prefer. Screws or bolts are used to secure everything in place. Put them just to the side of the elements so as to press against them when tightened. The antenna in the drawing is vertically polarized which is best for FM work. The director and reflector elements are cut as according to the lengths in the drawing above. A straight pencil line should be drawn along the boom with an X mark for each hole to keep the holes aligned at the same plane. The hole size chosen should provide a...
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April 7, 2015The Slim Jim Antenna The Slim Jim is a vertically polarized omnidirectional end-fed antenna having considerable “gain” and this is concentrated almost parallel to ground toward the horizon rather than skyward making it more efficient than a ground plane type antenna by about 50 percent better. It can be built for almost any frequency! ( Below 10 meters it gets VERY tall ) Due to it’s SLIM design, there is very little wind loading. It is fed with 50 ohm coax. It uses a ‘J ‘ type matching stub (J Integrated Matching = JIM), hense the name SLIM JIM. Credit for the original design goes to F.C. Judd, G2BCX. Since the vertical angle of radiation is so narrow, about 8 degrees toward the horizon, it usually out performs 5/8 λ or groundplane type construction due to their much higher angle of radiation. It is estimated that the Slim Jim appears to have about 6dB gain over a 5/8 λ antenna due to the extreme low angle of radiation. (Most of the radiation is directed toward the horizion making the “gain” appear much greater than other vertical type antennas it has been compared to with A/B testing) Editor’s note: There are many gain figures quoted for this antenna and also various descriptions of the actual type of antenna on various websites. Some have even stated that, “In fact I found it outperformed a 1/2λ over 1/2λ over 1/2λ colinear!” No matter what you call it, it seems to do an excellent job according to most reports. What have you got to loose? Please let us know your results…..email us! n4ujw AT hamuniverse.com. Using heavy duty construction would make this a good omni repeater antenna. When correctly matched for lowest swr, it has wide bandwidth. Construction details: NOTE: NO PART OF THIS ANTENNA SHOULD...
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March 31, 20152015 National Hurricane Conference Amateur Radio Presentations and Workshops Austin Convention Center — Austin, TX Tuesday, May 31, 2015 Today at 1830 UTC the Amateur Radio presentation at Broadcast live streaming video on Ustream
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December 23, 2014I bought myself an Audio Technica AT2020 for my ham radio rig. I have the adapters and PTT(push to talk) button coming soon. The only thing weired about this mic is I had to but several adapters and cables to make it work plus a phantom power supply. Every ham and every website rates this mic 5 out of 5. Looks slick and when I tried it on my computer it sounded great. I will take pictures once its all setup and ready. Off of Audio Technica Website http://www.audio-technica.com/cms/resource_library/literature/49f63e6efc082082/at2020_english.pdf Audio-Technica’s stringent quality and consistency standards set the AT2020 apart from other mics in its class. Its low-mass diaphragm is custom-engineered for extended frequency response and superior transient response. With rugged construction for durable performance, the microphone offers a wide dynamic range and handles high SPLs with ease. The AT2020: the new standard for affordable side-address studio condensers. The price/performance standard in side-address studio condenser microphone technology Ideal for project/home-studio applications High SPL handling and wide dynamic range provide unmatched versatility Custom-engineered low-mass diaphragm provides extended frequency response and superior transient response Cardioid polar pattern reduces pickup of sounds from the sides and rear, improving isolation of desired sound source Pivoting, threaded stand mount attaches securely for easy and precise placement of the microphone ELEMENT – Fixed-charge back plate, permanently polarized condenser POLAR PATTERN – Cardioid FREQUENCY RESPONSE 20-20,000 Hz OPEN CIRCUIT SENSITIVITY –37 dB (14.1 mV) re 1V at 1 Pa IMPEDANCE – 100 ohms MAXIMUM INPUT SOUND LEVEL – 144 dB SPL, 1 kHz at 1% T.H.D. NOISE – 20 dB SPL DYNAMIC RANGE (typical) – 124 dB, 1 kHz at Max SPL SIGNAL-TO-NOISE RATIO – 74 dB, 1 kHz at 1 Pa PHANTOM POWER REQUIREMENTS – 48V DC, 2 mA typical WEIGHT – 12.1 oz (345 g) DIMENSIONS...
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December 8, 2014My latest build project. I found the project relatively easy a few day project doing it at night after work. There was a lot of soldering and involved and wire stripping over all it was a very easy project and well worth the time. The parts and materials are of good quality and easy to work with. Very much enjoyed the project. From The Box Assembly of this XP-15 Regulated Variable Power Supply Kit will prove to be an exciting project and give much satisfaction and personal achievement. If you have experience in soldering and wiring technique, you should have no problem following the detailed instructions that are provided and successfully assembling of this kit. The Variable Voltage Power Supply Kit is a handy portable power supply with a variable output voltage of 15VDC. Specifications: Input voltage – 120VAC, Output voltage – 1.25 – 15VDC, Output Current – 0.5A @ 8V, 0.3A @ 12V, 0.2A @ 15V, Short Protected IC Thermo, Mounted in a rugged Bakelite case.Made in the United States.
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December 3, 2014http://fireballs.ndc.nasa.gov/ EARLY GEMINIDS: Earth is entering a stream of debris from “rock comet” 3200 Phaethon, source of the annual Geminid meteor shower. The shower is not expected to peak until Dec. 14th, but NASA meteor cameras are detecting Geminid fireballs over the USA two weeks early. Visit http://spaceweather.com for images and updates. AURORA WATCH: A high-speed solar wind stream is buffeting Earth’s magnetic field on Dec. 1-2. High-latitude sky watchers, especially those around the Arctic Circle, should be alert for auroras in the nights ahead. Geomagnetic storm alerts are available from http://spaceweathertext.com (text) and http://spaceweatherphone.com (voice).