Showing posts with label EMCOM. Show all posts
Showing posts with label EMCOM. Show all posts

Wednesday, March 21, 2012

Ham Radio and Mesh Networks

Lately I've been fascinated by the capabilities of mesh networks. The ability to quickly create ad-hock computer networks could be an invaluable resource for amateur radio operators in general and particularly for emergency communications (EMCOM)

Linksys WRT54GL Router
The particular device and software I have been experimenting with is the Linksys WRT54G router and HSMM-MESH firmware from http://hsmm-mesh.org/.

Installing the HSMM-MESH firmware changes the way the Linksys router functions and allows it to automatically connect to other HSMM routers in a mesh network. No special configuration is required after setting your callsign. All TCP/IP configuration is pre-configured, even down to automatically assigning addresses to connecting clients.

Mesh Network Diagram
Mesh networks are highly fault tolerant. Every router in the network is aware of every other router and has the ability to move network packets through from one unit to another provided there is a link, or chain of linked routers, between them.
In the diagram to the right each router is represented by a numbered circle. If router number 6 were to fail then network packets that needed to move between router 1 and 7 would travel through routers 2 & 3 or 5 & 10 until 6 was repaired. All this happens automatically and quickly enough so that there is no disruption to the traffic.

Anything you can access on a normal computer network can be made to work on a mesh network. Some of the services that have been demonstrated include email, voice over IP (VOIP), video conferencing, file sharing, web servers & groupware applications.

With simple modified antennas the modest output power from the WRT54G (100 to 200mW) can be used to reach distances of many miles or tens of miles with directional antennas. Mounting the router on a mast in a sealed enclosure can reduce losses from long cable runs while running off 12V power makes them compatible with ham radio power sources including solar and wind power.

The example to the left is from NG5V located on hsmm-mesh.org and consists of an omni-directional external antenna and a lawn sprinkler controller box from a popular home improvement store.

Did you know that ... Frequencies used by channels one through six of 802.11b and 802.11g fall within the 2.4 GHz amateur radio band. Licensed amateur radio operators may operate 802.11b/g devices under Part 97 of the FCC Rules and Regulations, allowing increased power output but not commercial content or encryption.

I hope to acquire a few more WRT54G routers and put together a mesh network in the Katy TX area as a resource for experimentation and education in an area not normally touched upon by regular amateur radio operators. Who knows what the future holds & it behooves us to investigate this technology and bend it to our own needs.

The Amateur is Progressive ... He keeps his station abreast of science. It is well built and efficient. His operating practice is above reproach.

Tuesday, February 7, 2012

The KN-Q7A - A new 40M SSB 10W transceiver kit

Amateur radio kit builders have had greater opportunities to construct high-end equipment thanks, in part, to more economical production processes. Online services allow kit manufacturers to farm out circuit board production to large workshops where jobs are batched together into larger production runs with significant cost savings. A number of suppliers are now willing to sell in smaller amounts while maintaining low costs due to automated on-line processing. The end result has been an increase in the number of kits available of significant complexity including rigs with using sideband, digital signal processing and software defined radio.

One new SSB rig kit is the KN-Q7A available from Adam Rong BD6CR/4, designed by Shi Ke BA6BF. The KN-Q7A is a 40M SSB transceiver in a compact case with VXO tuning and 10W power out. This style of rig would be ideal for back-packing, camping or as a compact emergency transceiver.

It would be interesting to see how this would pair with the NUE-PSK Digital Modem for a ultra-compact portable PSK31 station if the VXO could be made to tune to 7.035 MHz

The KN-Q7A - 40M with VXO SSB 10W
The KN-Q7A is available directly from http://crkits.com/ or from their US distributor http://www.qrvtronics.com/HAM-Radio

Price for the KN-Q7A kit is $125 USD, a suitable microphone is available for an additional $25 USD.

Specifications

• Dimension: 153 mm x 97 mm x 40 mm, not including protruding features
• Weight: 500 g or 1.1 lbs
• Power Supply: 12~13.8 V, 3 A
• Current consumption: 30 mA in RX and about 2 A in TX @ 13.8 V
• RF output: about 10 W PEP @ 13.8 V
• Spur suppression: better than -43 dBc
• Sensitivity: better than 0.5 μV at 10 dB SNR
• IF filter: 6 pole crystal ladder filter + 1 pole post IF amplifier crystal filter
• IF bandwidth: about 2.0 kHz
• IF frequency: 8.467 MHz or 8.192 MHz, depending on the selected tuning range
• Frequency tuning range: about 20 kHz in VXO type. Five options: 7.050~7.070 MHz,
7.080~7.100 MHz, 7.145~7.165 MHz, 7.200~7.220 MHz, or 7.280~7.300 MHz
• Connectors:
• Speaker output: 3.5 mm connector, mono output
• Microphone input: 8-pin, can be configured to be compatible with electret
microphones
• Antenna connector: SL-16 type (M or SO-239 type equivalent), rear panel mount
• Controls:
• IF Gain Control: act as volume control
• Tune Control
• On board RF Attenuator trimmer to eliminate broadcast interference

Thursday, January 12, 2012

Amateur radio event helps youths connect to others around the world

An important part of Ham Radio is public service and while not every ham has the time or ability to contribute, those that do are able to connect to communities in a very meaningful way.
Ham Radio can provide a communications service that is very different to the corporate product of AT&T or Comcast. Ham Radio is an essentially a grassroots organisation drawn from the community itself.

A recent article in the Daytona Beach News-Journal highlighted some of the activities during Amateur Radio Kids Day ...
Mark Estes, Correspondent for the Daytona Beach News-Journal

PALM COAST -- Herschel King Sr. Park was abuzz with activity as members of the Flagler Amateur Radio Emergency Service Organization and Flagler Palm Coast Amateur Radio Club joined in Sunday for the American Radio Relay League's national Children's Day event.

Before the event officially began, there was plenty to do as members of both clubs readied a number of radio set-ups. With the help of members of Palm Coast Boy Scout Troop 402 various antennas were deployed in the trees in preparation for a day of contacting amateur radio enthusiasts around the continent.

The dozen Boy Scouts, along with parents and Scout leaders, bicycled 10 miles to the site as one of the requirements for their cycling merit badge. Eight of the Scouts are working toward their radio merit badges and for some, this outing would complete the requirements for the badge.

During the day, other families visited to learn about amateur radio and this was good news for Bill Schwartz, Flagler County emergency coordinator for ARES.

"We're introducing amateur radio to youth," Schwartz said. "For the Scouts, they're going to try to get some requirements for their merit badges. For us, it's practice so if there were a disaster we could set up an HF station anywhere."

The order of the day was to have the licensed adults make the initial contacts and then hand the mic over to their charge for a conversation.

"We expect to be able to get the United States, Canada and South America," Schwartz said. "The kids have to spend 10 minutes on the air for the merit badge. So far it has been all theoretical for them. There are certain places where we're going to try to get in touch with other kids."

Any contact and conversation was good. If the prospect of talking on the radio to strangers, mostly adults, was a bit daunting, Jake Dobson, 11, never let on. Despite a bit of local interference, Jake confidently held the mic and made the appropriate acknowledgments while learning a bit of conversational radio shorthand from John Woika. He made his required contacts in good order.

"It was interesting and fun," Jake said.

The day started a little rougher for Coby Queen, 12, as an equipment malfunction resulted in a fall and a scraped arm during the 10-mile bike ride. Things started slow for him on the radio as well. The first contact his adult partner, Norm Riquier, found was in an extended conversation; the next faded before he could talk to them. Getting a good signal was elusive, but eventually Coby contacted New Mexico and then, Guatemala.

Michael Levin, 13, and Ian Medley, 16, got a bit of a treat when they did their radio work in Mike Lee's communications van. Chief innovation officer at Palm Coast Data, Lee designed and equipped it as a proof-of-concept van seemingly capable of very type of communications except smoke signals. Lee and assistant emergency coordinator Eddie Cail served as adult partners for Levin and Medley.

The older hams would certainly like to see some of the participants take up amateur radio as a hobby.

"We have a 119 merit badges in the program and the boys usually go into some profession or pick up some hobby out of these during their lifetimes," Scoutmaster Tony Conti said.

This is the first time the Flagler clubs have participated in the national Children's Day event, but they expect to be doing so again in the future.

"We're hoping to do more of these throughout the year, keeping the kids active and give them something to do," Cail said. "The bands are really hot right now for a lot of radio stuff so we're hoping to make some good contacts and let them see what it's like to get on the air."

More information on ARRL Kid's Day is located here : Kids Day 2012: Sunday, January 8 & Saturday, June 16

Saturday, December 31, 2011

New video from ARRL : The DIY Magic of Amateur Radio

From the ARRL:
ARRL's new video, "The DIY Magic of Amateur Radio," is an 8-minute video that follows some of the innovative, imaginative and fun ways "hams" use radio technology in new and creative ways. The presentation is directed toward the DIY (do it yourself) movement, which is inspiring a new generation of creators, hackers and innovators. The message should be helpful for existing members to shape the ways they understand and talk about ham radio.


Tuesday, December 27, 2011

What we can learn from a Mexican drug cartel.

The AP carried the following article detailing an extensive, low cost & flexible radio repeater system employed by a Mexican drug cartel to coordinate their operations. The system seems to exceed the sophistication of regular amateur radio linked repeaters while improving on independence from grid power. America's ham radio community has the required technology, know-how and government support to upgrade our repeater systems ... what is stopping us from pushing the technology further?

Mexico's cartels build own national radio system



MEXICO CITY (AP) — When convoys of soldiers or federal police move through the scrubland of northern Mexico, the Zetas drug cartel knows they are coming.
The alert goes out from a taxi driver or a street vendor, equipped with a high-end handheld radio and paid to work as a lookout known as a "halcon," or hawk.
The radio signal travels deep into the arid countryside, hours by foot from the nearest road. There, the 8-foot-tall (2-meter-tall) dark-green branches of the rockrose bush conceal a radio tower painted to match. A cable buried in the dirt draws power from a solar panel. A signal-boosting repeater relays the message along a network of powerful antennas and other repeaters that stretch hundreds of miles (kilometers) across Mexico, a shadow communications system allowing the cartel to coordinate drug deliveries, kidnapping, extortion and other crimes with the immediacy and precision of a modern military or law-enforcement agency.
The Mexican army and marines have begun attacking the system, seizing hundreds of pieces of communications equipment in at least three operations since September that offer a firsthand look at a surprisingly far-ranging and sophisticated infrastructure.
Current and former U.S. law-enforcement officials say the equipment, ranging from professional-grade towers to handheld radios, was part of a single network that until recently extended from the U.S. border down eastern Mexico's Gulf coast and into Guatemala.
The network allowed Zetas operatives to conduct encrypted conversations without depending on the official cellphone network, which is relatively easy for authorities to tap into, and in many cases does not reach deep into the Mexican countryside.
"They're doing what any sensible military unit would do," said Robert Killebrew, a retired U.S. Army colonel who has studied the Mexican drug cartels for the Center for a New American Security, a Washington think tank. "They're branching out into as many forms of communications as possible."
The Mexican army said on Dec. 4 that it had seized a total of at least 167 antennas, 155 repeaters, 166 power sources, 71 pieces of computer equipment and 1,446 radios. The equipment has been taken down in several cities in the Gulf coast state of Veracruz and the northern states of Nuevo Leon, Coahuila, San Luis Potosi and Tamaulipas.
The network was built around 2006 by the Gulf cartel, a narcotics-trafficking gang that employed a group of enforcers known as the Zetas, who had defected from Mexican army special forces. The Zetas split from the Gulf cartel in 2010 and have since become one of the nation's most dominant drug cartels, with profitable sidelines in kidnapping, extortion and human trafficking.
The network's mastermind was Jose Luis Del Toro Estrada, a communications expert known as Tecnico who pleaded guilty to conspiracy to distribute cocaine in federal court in Houston, Texas, two years ago.
Using millions of dollars worth of legally available equipment, Del Toro established the system in most of Mexico's 31 states and parts of northern Guatemala under the orders of the top leaders in the Gulf cartel and the Zetas. The Gulf cartel boss in each drug-smuggling territory, or plaza, was responsible for buying towers and repeaters as well as equipping his underlings with radios, according to Del Toro's plea agreement.
Del Toro employed communications specialists to maintain and run the system and research new technology, according to the agreement.
Mexican authorities, however, presented a different picture of the cartel radio infrastructure, saying it was less monolithic than the one described by U.S. authorities. A Mexican military official denied that the army and navy have been targeting one network that covered the entire Gulf coast. The operations had been focused on a series of smaller, local systems that were not connected to each other due to technical limitations, he said.
"It's not a single network," the official told The Associated Press on condition of anonymity due to the sensitivity of the topic. "They use it to act locally."
In recent years, reporters traveling with the Mexican military have heard cartels using radio equipment to broadcast threats on soldiers' frequencies. The military official told the AP that the signals are now encrypted, but cartels are still trying to break in.
At least until recently, the cartel's system was controlled by computers that enabled complex control of the radio signals, allowing the cartel to direct its communications to specific radios while bypassing others, according to Grupo Savant, an intelligence and security consulting firm in Washington that has firsthand knowledge of Mexico's cartel operations.
The radio system appears to be a "low-cost, highly extendable and maintainable network" that shows the Zetas' sophistication, said Gordon Housworth, managing director of Intellectual Capital Group, LLC, a risk- and technology-consulting firm that has studied the structure and operations of Mexican cartels and criminal groups.
Other Mexican criminal organizations maintain similar radio networks, including the Sinaloa cartel, based in the Pacific coast state of the same name, and the Barrios Azteca street gang, which operates in Ciudad Juarez, across from El Paso, Texas, a U.S. law-enforcement official said. The Zetas' system is the largest, however, the official said, speaking on condition of anonymity because of the sensitivity of the topic.
The Mexican raids are "a deliberate attempt to disrupt the business cycle of the cartels," said one former law-enforcement official with direct knowledge of the network. "By going after command and communications you disrupt control."
Law-enforcement officials and independent analysts described the operations against the Zetas' communications system as significant short-term victories in the fight against the cartel.
"The seizures show that the organization is scrambling," said Steven Dudley, co-director of InSight, a group that analyzes and investigates organized crime in Latin America.
The longer-term impact is unclear. The cartel has had little difficulty in replacing radio gear and other equipment seized in smaller operations in recent years. And contacts among the highest-ranking Zetas operatives tend to take place in highly encrypted communications over the Internet, according to Grupo Savant.
Certainly, cartel radio equipment is a near-ubiquitous presence for Mexicans living along the front lines of the drug war.
In the state of Tamaulipas, across the border from eastern Texas, many antennas are concealed in the foliage of the rockrose, an invasive shrub that has spread across much of the state's open land.
Even from a few feet (meters) away it's nearly impossible to see the towers or their power cables.
In Nuevo Laredo, the Zetas' first stronghold, antennas sprout from rooftops and empty lots. One soldier told the AP that even when authorities took down an antenna there, it was swiftly replaced.
___
Associated Press writers E. Eduardo Castillo in Mexico City and Efrain Klerigan in Victoria, Tamaulipas, contributed to this report.

Wednesday, November 30, 2011

Ham activating a Rest Area help Australian sailor adrift off the coast of Mexico.

11/24/2011 -- IHRAS Members assist Australian Sailor adrift near Mexico.
Jon - N5JLD


Well it went sort of like this. KF5FEI and I showed up at the rest stop just before 5 am CST. We got set up and the noise from the lights lighting up the rest stop was horrible. Way to much for SSB even with DSB, oh well so I waited for daylight. Bill was setup for PSK31 and not having much better luck with all the noise. As daylight arrived the band started to wake up with it. Bill made a handful of contacts and I could hear a lot on phone but no one heard me. I switched to Bill's antenna and spun the dial to 14.325 and called CQ. Well VK3LAA came back and answered my call. That's right VK. Problem was that he was not in Australia but off the coast of Mexico. In a boat, dead in the water and looking for help. Bill started looking on how to get a hold of the Coast Guard while I was talking to him getting to location and his current status. He was in a 35 foot sailboat but his motor was not working and he is adrift with no winds. Well Bill got a hold of the USCG in California and we were relaying information back and forth. The USCG was trying to raise the Mexican Coast Guard as VK3LAA was having no luck on Maritime VHF. Bill then called Scott McBain to see if we could find a club member with a base station and maybe a beam that might be better suited, remember we were portable at a rest stop south of Fort Worth. Robert AD5VJ signed on and took over the lead as he was able to get with the folks over on 14.300 with the Maritime Mobile Net. They in turn got in contact with all their support personnel and got him the help he needed. I signed off with VK3LAA as he was in very good hands. I spun the dial again and made contacts with CA and MO. We then called it a day, packed up and headed for Turkey time.

Just your average day and the rest stop...........

73's
Jon N5JLD


The above story was posted on the "Rest Areas On The Air" Yahoo group

Tuesday, November 1, 2011

2M Tape-Measure Yagi Antenna

A great antenna for 2M that can be built from parts obtained from HomeDepot or Lowes is the 2M tape-measure yagi antenna.

The link to the plans and instructions is here.

Two meter antenna built using PVC pipe and an inexpensive steel tape measure.