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Amateur Radio

  • In 2008/2009 Alan Melia G3NYK and I wrote a series of features on understanding LF and HF propagation for the Radio Society of Great Britain’s (RSGB) “RadCom” magazine. My features consisted of a month-by-month look at each HF band in turn, showing the reader the propagation modes behind each band and explaining some of the technicalities of ionospheric propagation. I looked at the D, E and F layers, Sporadic E, the MUF/LUF, using solar data, propagation programs, NVIS and much more. Alan then took over and wrote three detailed features on LF propagation. We are told that the features were well received and as a result I have managed to persuade the RSGB to allow me to put them together into a single document, which is now freely available for amateurs worldwide to download. http://www.infotechcomms.co.uk/Understanding_LF_and_HF_propagation.pdf
  • I tried this as a little project over the weekend. Since the arrl had a ssb contest over the weekend. http://www.arrl.org/sweepstakes I used the mixing board that my band and I use when we practice at my house called mackie mixer but the behringer mixer in the example in youtube video below works just fine. I hooked the mackie mixer with my icom 706. I found if nothing else being able to clean up audio on the receive was a great tool and gave me an edge in contest since I was able to clean up audio and get contacts that for months I have been struggling to get. Cleaning up my audio on the send was help as well I got great audio reports the entire contest. Its hard to say if sending was better cause I can not here myself on the other end I was however getting 599 from contesters. The receive is definitely worth it I was able to take far away sounding, crackley, echoy and distorted voices and clean them up and make them clear to be able to hear better to make the contact. You can do this with almost any cheap mixer and a few adapter cables its worth the time and the few dollars. Even if your just going to use it for receive. Our friend Bob Heil has an example of how to do this on youtube
  • November 21, 2014

    Fletcher Munson Curves In Ham Radio

    The Fletcher Munson curves are one of many sets of equal-loudness contours for the human ear, determined experimentally by Harvey Fletcher and Wilden A. Munson, and reported in a 1933 paper entitled “Loudness, its definition, measurement and calculation” in the Journal of the Acoustic Society of America. The first research on the topic of how the ear hears different frequencies at different levels was conducted by Fletcher and Munson in 1933. In 1937 they created the first equal-loudness curves. Humans don’t hear all frequencies of sound at the same level. That is, our ears are more sensitive to some frequencies and less sensitive to other frequencies. In the early 1930’s Dr. Fletcher and Dr. Munson, audio pioneers at Bell Labs discovered that the human ear hears differnetly at varioius loundness levels. At 130+ dB SPL we hear almost flat. But we hear lows and highs poorly at lower volumes (lower SPL) and it gets worse the softer the sound. To complicate matters further we all loose our hearing above 14,000 Hz as we age! The important thing to understand about sound is the volume (in SPL) affects your perception of bass and treble response significantly. What sounds quiet one way, sounds different loud. The same thing is true for sources and microphones. A mic that sounds good at low level may sound terrible at high level! Fletcher-Munson also discovered that the dynamic range of the human ear was 120 dB! How does this relate to Ham Radio After several years of experimenting and listening, the Heil Sound team discovered that most of the old line favorites have their frequency response in the wrong place. Just about every dynamic microphone has a mid-range response peak that is in the wrong place. To fix this problem of audio quality and sound we...
  • MADISON COUNTY, Tenn. — Life in the digital age is filled with the World Wide Web, which is why some first responders wanted to re-wire their ham radio skills Friday. In order to continue communicating if the Internet fell victim to a mass cyber attack, agencies from across Tennessee would turn to radio. “We can actually send email and attachments, video and what-not via ham radio without ever using Internet,” said Mike Winslow, risk manager for Madison County. First responders would use ham radio frequencies to email, send pictures and messages if traditional email were gone. “Their contacts can be in the emergency ops center, utilizing their emails as they would on a daily basis,” said Jimmy Floyd, operations manager for the Jackson-Madison County Emergency Management Agency. The system in Madison County works via software installed on a laptop. That can send messages to a radio in another part of the country. “The software can send the digital information via radio waves to another station with similar equipment and then be able to pull it up on the screen and print it out,” Winslow said. Floyd says this system allows other emergency and government agencies to request supplies or equipment during an Internet-less disaster. Officials say even a solar flare can cause Internet loss.
  • The largest sunspot seen in about a quarter century has produced another powerful X-class flare today, the sixth in less than a week. “This was the sixth X-class solar flare from NOAA 2192, a record for the number of X-class flares generated by a single group so far this solar cycle. It was also the fourth X-class flare since last Friday, continuing a period of intense flaring activity. This sunspot group has grown again a bit, and maintains its magnetic complexity. A degradation of the HF radio-communication was observed over South-America, the Caribbean, and West-Africa.” The last sentence is referring to some radio communications blackouts that have occurred in these areas because of the flares. http://science.slashdot.org/story/14/10/29/0319206/largest-sunspot-in-a-quarter-century-spews-flares
  • Actor Tim Allen, left, who portrays a ham (KAØXTT) on his hit ABC-TV comedy “Last Man Standing,” has earned a real-life amateur license, according to the show’s producer, John Amodeo, NN6JA. Allen is now licensed as KK6OTD. Amodeo also reported on the successful running of the second “K6H Hollywood Celebrates Ham Radio” special event from the program’s sound stage, which includes a fully functional amateur station. (Photograph courtesy of the ARRL)
  • Amateur Radio operators will be on the air October 14-20 to let the public know about the National Wildlife Refuge System by operating from refuges around the US during National Wildlife Refuge Week. They will be highlighting refuge features, wildlife, and geography while contacting other stations across the US and North America. The goal for participants is to combine their communication skills with their enjoyment of the outdoors to help others learn about the National Wildlife Refuge System. Authorized, safe, responsible access to refuges is sanctioned by this event. As of 2013, hams also may operate from wildlife refuges, areas or preserves managed by any state, territory, or Canadian province. Due to the partial US Government shutdown in 2013, NWR Week event coordinators suspended rules that normally confine NWR Week stations operations within the boundaries of national wildlife refuges and wildlife areas. Stations were allowed to operate from any location for the 2013 event. Members of the KP1-5 Project team announced earlier this year that the US Fish and Wildlife Service had agreed to allow an Amateur Radio operation from Navassa National Wildlife Refuge (KP1). “The operation will occur within the next 18 months and will be coordinated with the USFWS work flow,” the August announcement said. The KP1-5 Project has operated from National Wildlife Refuges since 1993, when Bob Allphin, K4UEE, operated from the Howland Island National Wildlife Refuge. Mike Thomas, NA5U, has operated from Tishomingo NWR, Wichita Mountains NWR, Hagerman NWR, Balcones Canyonlands NWR, Aransas NWR, Caddo Lake NWR, and, in 2009, as part of the K5D DXpedition to Desecheo Island NWR (KP5). A list of National Wildlife Refuge sites by state is available. Those still planning to operate from a National Wildlife Refuge must obtain permission from the refuge manager and submit an operating plan to have...
  • ARRL Headquarters is deploying Ham Aid kits to Hawaii as ARES volunteers stand ready to activate in the wake of the massive Puna volcanic lava flow that has been threatening some communities on the Big Island of Hawaii. The lava originated from new “vents” in the Earth as a result of the Mt Kilauea volcano, which began erupting more than 30 years ago. ARRL Pacific Section Manager Bob Schneider, AH6J, said Tuesday that while he doesn’t believe an ARES activation is imminent, lava flows can be unpredictable, and things can change rapidly. “Lava is a slow-motion disaster,” he said. “It’s not like a volcano, where the thing just blows up. It’s like a pot of soup.” ARRL Emergency Preparedness Manager Mike Corey, KI1U, said the Ham Aid kits going out to Hawaii include HF gear as well as VHF and UHF equipment. “We’re deploying an HF kit — an IC-718 transceiver, a tuner, and a dipole — and a VHF/UHF kit.” The latter includes a mobile transceiver and power supply as well as several handheld transceivers that have been programmed with local frequencies that may be needed before they’re shipped. Corey said the Ham Aid kits are a resource available to ARRL section leadership to add capacity during a disaster or emergency response. Schneider said that while there is no immediate need for the kits, “if they have it out there, and this thing changes, we’ll be prepared. It’s better to have it and not need it, than need it and not have it.” More via ARRL.
  • The national ARRL Simulated Emergency Test (SET) is slated for the October 4-5 weekend, although the window for local and regional exercises is September 1 through November 30 each year. All groups conduct their events over the course of 48 hours. The SET is a nationwide exercise in disaster response and emergency communication, administered by ARRL emergency coordinators and net managers, in which volunteers respond to a mock emergency or disaster, such as an earthquake or hurricane. Members of the Amateur Radio Emergency Service (ARES), the Radio Amateur Civil Emergency Service (RACES), the National Traffic System (NTS), SKYWARN, the ARRL Field Organization, and other groups work together to plan and develop simulated emergency and disaster scenarios, in consultation with the various served agencies that rely on radio amateurs during emergencies. The SET gives volunteer public service communicators the opportunity to focus on their capabilities, strengths, and weaknesses while interacting with NTS nets. It also provides a public demonstration — to served agencies such as the Red Cross, state and local emergency managers, and the news media — of the value that Amateur Radio provides. The SET helps radio amateurs gain communication experience using standard procedures and a variety of modes, under simulated disaster-response conditions. Participating groups earn points toward an overall SET score, adding a competitive component to the activity. Results are listed inQST (see pages 71-73 the July issue of QST for the 2013 SET results). Visit the ARRL Public Service/Field Services page and click on “SET Score Card” for an explanation of how points are earned. Many ARES groups across the country will be participating, and all ARES members are invited to support the national SET and their local ARES group’s activity. During this year’s SET, participating ARES/NTS members can earn SET bonus points by participating in the...