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Ham Radio

  • 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. via WBBJTV
  • 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...
  • 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...
  • NWS Binghamton Winter Weather Preparedness Webinar Thursday September 25th 2014 1 pm Register Today Space is limited. Reserve your Webinar seat now at: https://www2.gotomeeting.com/register/209515346 For audio on this call… Dial: 1-203-607-5026 Passcode: 636205 In order to prepare for the upcoming winter season, I wanted to invite you to a webinar that will cover the following topics: – Winter climatology – Types of Winter Storms – NWS Winter Weather Products and Services – Proposed changes to winter storm criteria. – Snow squalls alerting program. – Winter 2014-15 Outlook: an early look. – Winter Preparedness including NY and PA winter weather awareness weeks. Title: NWS Binghamton Winter Weather Preparedness Webinar Thursday September 25th 2014 1 pm Date: Thursday, September 25, 2014 Time: 1:00 PM – 2:00 PM EDT After registering you will receive a confirmation email containing information about joining the Webinar. System Requirements PC-based attendees Required: Windows® 8, 7, Vista, XP or 2003 Server Mac®-based attendees Required: Mac OS® X 10.6 or newer Mobile attendees Required: iPhone®, iPad®, Android™ phone or Android tablet
  • ATLANTA –  Seeking reliable backup communication in a crisis, emergency managers are finding new solutions in an old technology: ham radio. “It’s just another avenue, another opportunity for us to be able to communicate,” said Herb Schraufnagel, public safety captain with Emory University Hospital Midtown. Emory HealthCare is among a growing number of hospital systems to adopt ham radio. Hospital administrators and government officials took a lesson from Hurricane Katrina, which left some Gulf Coast medical centers isolated from the outside world, as landlines and cell towers failed. When power, phone and Internet services go down, a battery-powered amateur radio and portable antenna can provide that crucial link to the outside world. “Ham radio will never die,” said Barry Thomas, Sr., a ham radio enthusiast and employee at Emory University Hospital Midtown. “The quickest means of communication is Morse Code. It’ll get out when none of this will,” Thomas said, referring to a room filled with computers and smartphones.’ “It is interesting that some of the technology that has been around for 80, 90, 100 years is still relevant,” said John Davis, a ham radio enthusiast. In addition to major hurricanes, Davis says the terrorist attacks of September 11, 2001 rekindled interest in ham radio as a public safety tool. The Georgia Emergency Management Agency (GEMA) has set up a permanent ham radio station in its command center. “We look at ham radio operators just like GEMA staff, just like DOT staff and Georgia State Patrol staff,” said GEMA Director Charlie English. “They are a critical partner with us.” The number of ham radio licenses is at an all-time high in the U.S. (723,182, as of April, according to Federal Communications Commission (FCC) data compiled by Joe Speroni of the Amateur Radio Education Web Site, ah0a.org. “I really hope that it stays relevant and that we can be a resource to...
  • May 15, 2014

    Hand’s On With Ham Radio

    Radio Shack’s original and core customer used to be the young man who was a tinkerer: ham and shortwave radio operators, guys who hacked telephones and built their own stereo components and even some early computer builders. Now kids are passively entertained with a cornucopia of electronic gadgets bought with mummy and daddy’s money and built in Asian factories. They would rather surf YouTube and Facebook then open up a Popular Mechanics magazine. They would rather make vine videos then make gadgets themselves. Before the internet was available in the 90’s you did not watch Netflix for entertainment you took apart your Nintendo to see how it worked. The guys who were interested in electronics did some impressive stuff. Some of you may remember Heathkits. You could build a powerful stereo system from their components for about half the cost of a store-bought version. These were very popular, and the guys who built them justifiably proud of their work. Some of the guys I knew who did this sort of thing went on to successful careers in computers and electronics. Shop classes are electives. Vocational education like automotive, electronics and computers are guaranteed jobs yet college kids pick majors where no jobs are available. Entertainment is a completely passive experience as well. Pride in something you built yourself has been replaced by pride in how far you’ve advanced in Angry Birds or Candy Crush. If kids today don’t get exposed to hands-on activities in their teens, if they’re not forced by boredom or financial need to build stuff, it’s ‘highly unlikely they’ll seek out, or have the aptitude for the ultimate in hands-on careers.