The introduction of C4FM / FDMA technology is the beginning of a new digital communication system in Amateur Radio world. The most attractive advantage of digital communication is the ability to transfer large amounts of data. The 12.5 kHz channel spacing in using the C4FM FDMA digital modulation mode allows high-speed data communication with reliable voice communication and strong error correction performance.
C4FM FDMA offers a 9.6 kbps data transfer rate speed. It differs significantly from existing digital radio systems and expands the possibilities for interesting amateur radio activities in the future.
The C4FM / FDMA technology provides three digital modes and an analog mode (FM) V / D-mode voice and data communication in the same time frame. This mode allows voice data with GPS position data and the ID data to be sent in the same time frame. In addition, transmitting the voice data with strong error correction data, this mode that contributes to the stabilization of the digital communication. This mode is the basic mode of C4FM FDMA Digital HAM radio system.
Data FR mode uses the full data rate of capacity for the Transmission of data. This mode allows you to transfer large amounts of data, text messages, pictures and voice notes data at twice the speed as the V / D-mode. Voice-FR mode uses the full data rate of capacity for voice data. This mode allows a clear high quality voice data transmission.
Analog FM mode is the same as the current FM mode used by all VHF / UHF amateur radio operators . A very useful Automatic Mode Select function identifies and selects These four modes automatically upon receipt of the respective signal.
System Fusion – Mostly referred to as Fusion is the newest digital radio mode. It was designed by Yaesu and is not an open standard. Yaesu is the only manufacturer of radios for this mode. Yaesu repeaters are true multi-mode capable and can replace an existing analog repeater while still providing digital capabilities.
I monitor 443.050 (locally), which connects me Worldwide to Americas Link.
I run a Yaesu FT70D handheld radio, I can hook it up to an outdoor antenna if needed. Works great!
Before you can get on the air, you need to be licensed and know the rules to operate legally.
Find a Class: Find a license class offered in your local area.
Take Practice Exams: Get a feel for how the exam is going to go and what you should really focus on while studying.
New Hams Info website – NewHams.info site. Its purpose is to provide training, information and general encouragement to new or prospective amateur radio operators (hams). Sort of a virtual “Elmer”, as we say. Experienced hams should find it interesting and useful as well.
Amateur radio – a 21st Century hobby
Whether you enjoy writing software, getting hands-on with practical equipment, developing new technology or simply want to use what’s already there to communicate with others across the world, you’ll find all of this – and more – within amateur radio.
The Oregon HamWAN program has received an ARDC grant of $88,000 to expand its digital communications network.
The project aims to enhance amateur radio digital and emergency communications capabilities between Portland and Salem, Oregon.
The nonprofit plans to expand its digital communications network by deploying 12 network backbone distribution sites between the two cities. Eventually, the sites will connect to the Puget Sound Data Ring, which currently extends from Seattle to Vancouver, Washington.
The network would allow emergency management personnel to communicate in the event of a disaster, such as a major earthquake, that disrupts telecommunications systems.
In such cases, amateur radio operators will be able to quickly set up network nodes where they are needed to provide emergency communication via the Oregon HamWAN digital network.
ARDC is a California-based private foundation that supports innovative amateur radio projects. The foundation makes grants for projects and organizations that follow amateur radio’s practice and tradition of technical experimentation in both amateur radio and digital communication science.
Vietnam veteran Skip Fedanzo shows off the disaster response radio system in his Corte Madera home. Brontë Wittpenn / The Chronicle
Fedanzo is part of a civilian disaster response network relying on early 20th century technology. Alvin A.H. Jornada / Special to The Chronicle
Members of the Radio Communications Volunteers group gather with ham radio antennas for an emergency response exercise in San Rafael. Photos by Alvin A.H. Jornada / Special to The Chronicle
The group believes more primitive technology would be vital if cell phone towers and the internet go down.
At 10 a.m. on Wednesday, Skip Fedanzo was expecting an 8.0 earthquake on the Hayward Fault. Assuming his Corte Madera home didn’t slide down Ring Mountain, Fedanzo was set to make his way past his cell phone, laptop and land-line, heading to his garage for the only communication method he can count on to be still working — a ham radio.
Setting up in his rocking chair, at a window with a view stretching from Mount Tamalpais to the bay, Fedanzo’s plan had him pushing the power button to announce: “This is Skip, KJ6ARL; is anybody out there?” That is the call to bring a response from any or all of 15 ham operators spread from Novato to Point Reyes Station — and Operation Golden Eagle, an orchestrated region-wide emergency response exercise, will be on the air.
The simulation involves five Bay Area counties, where emergency service professionals exchange requests for information and resources after the presumed disaster. But only Marin among the five counties is operating without internet or cell phone capabilities. Instead, Marin is employing a network of amateur radio hobbyists who call themselves Radio Communications Volunteers. Acting under supervision of the Marin County Department of Public Works, RCV is providing vital communications between the emergency operations center and community-based organizations that serve the most vulnerable residents.
The goal is to have the county Board of Supervisors certify RCV as part of its official emergency response. The idea is that early 20th century technology — antenna to antenna, without reliance on cell towers, satellite dishes or cables — will be a vital tool when 21st century technology stops working, which Fedanzo expects to happen the moment the real disaster hits.
“The weak underbelly of America is that we are overly reliant on gadgets and gizmos,” said Fedanzo, 77, a retired software engineer who was trained as a radio operator while serving as a Marine in the Vietnam War. “The more complex the systems get, the more likely they can fail.”
This was made apparent in October 2019 when PG&E activated a five-day public safety power shutdown in Marin County to prevent wildfires from sparking in exceptionally dry, windy conditions.
“They throw the switch and the first thing that goes off is the internet,” said San Rafael ham operator Milt Hyams, 78, a retired county prosecutor who also served in Vietnam, as a captain in the Army Signal Corps. “Then after a few days the batteries in the cell towers started to go out and you couldn’t use cell phones. That was kind of a shock and an epiphany to folks.”
Hyams and Fedanzo both worked that blackout as volunteers with the Emergency Operation Center at the Marin County Sheriff ‘s Office. In the aftermath, they pitched the idea to build a countywide communications network using battery-powered radios and a relay signal atop Mount Tam. That was the start of Radio Communications Volunteers, RCV in the acronym-heavy code employed by ham operators.
In their lingo, RCV provides a service to VOAD (Voluntary Organizations Active in Disaster), which is affiliated with EOC (Emergency Operations Center) in cooperation with RACES/ACS (Radio Amateur Civil Emergency Services/ Auxiliary Communications Services). These are not truckers with clever handles killing time on their CB radios. All 16 RCV operators have been licensed by the Federal Communications Commission and assigned call letters.
“This is KJ6ARL, request radio check,” Fedanzo said on a recent practice day. He was sending a test signal to Hyams, who was parked in his Jeep Wrangler in Fedanzo’s driveway. “This is KM6ASI, checking in,” Hyams responded upon picking up the signal. His Jeep door bears the logo of the Marin Amateur Radio Society with the word “communications” in bold white letters.
Affixed above his left tail light is an antenna as long as the ones used for old-time FM car radios.
“Keeping it simple is our watchword,” said Hyams. “In a real emergency, getting on the air can be as easy as throwing a wire over a tree branch to act as an antenna. Then you don’t need a Jeep.”
RCV is a second response unit, after fire and law enforcement first responders who run a separate radio frequency, Marin Emergency Radio Authority.
“We’re not going to put on Superman suits and go out looking for downed buildings and power lines and put bandages on people,” Fedanzo said. “All of the immediate response will be handled before we get activated. We are mobile telephone booths providing long-haul support.”
For the Wednesday test, Fedanzo was tapped to be the net control operator for RCV, coordinating the hams. Each has been assigned a community-based organization, to which they are expected to carry all of their gear by car, bicycle or on foot, depending on how seriously they envision the scenario of an 8.0 quake to be — 8.0 is more than 10 times the magnitude of Loma Prieta in 1989 and could render roads useless. Once RCV arrives at a site and establishes a pipeline to the emergency operation center, the ham radio guys relay requests for information and resources.
Operation Golden Eagle is a one-day drill. But RCV can go much longer. Fedanzo maintains four days of battery power, plus a portable generator with a 5-gallon gas can to load into his Acura Sedan when he heads down from Ring Mountain and into the disaster zone.
He has not forgotten that after the Loma Prieta quake it took him 20 hours to make it home from Cupertino, 60 miles away. Hyams also has not forgotten his experience of that day, Oct. 17, 1989. He was in the District Attorney’s Office at Marin Civic Center at 5:04 p.m. when “all these law books started falling off the shelves and conking me on the head,” he said. He escaped into a hallway and ran into a county administrator who recruited him on the spot for the Emergency Operations Center.
It took 32 years to get to the RCV, and Hyams is ready for the test. He timed the 15-minute drive to the emergency center north of San Rafael. Once there for the Wednesday drill, he has the dispatch role for hams reporting in from service organizations including Community Action Marin, the Canal Alliance, the San Francisco-Marin County Food Bank and others.
“What Milt and I are doing is using our life experience and radio knowledge to help people communicate when they can’t do it any other way,” Fedanzo said.