The SBE Chapter 73' of the Air and DENVERSKYHUBLINK NET

Meets every Monday Night at 7pm Mtn time on the following linked repeaters and systems

AllStar Node 46079 Skyhub
ECHOLINK WØSKY-L Node 985839
YSF Reflector YSF 92722 US Skyhub Link - Denver Skyhub
DMR Talkgroup 310847
Yaesu Fusion Wires-X Room 46361 "DenverSkyhubLink"

Repeaters in Denver
449.450 mHz -5 mhz offset 103.5 pl analog
449.750 DMR Timeslot 1 Talkgroup 310847
448.350 Fusion digital Wires-X room 46361
"DENVERSKYHUBLINK"
449.625 Fusion Digital Wires-X room 46361
"DENVERSKYHUBLINK"

AND you can listen to the NET LIVE at:
https://www.broadcastify.com/listen/feed/25448/web

You can link your repeater, hotspot node, AllStar or DMR repeaters or radio's into the "DENVERSKYHUBLINK System anytime. Email Jack at KE0VH@OUTLOOK.COM for information

Spread-spectrum RF chirps are low-bandwidth—but they go farther than you'd think. //

Sure-Fi isn't intended to replace Wi-Fi at all. When Ars spoke to Sure-Fi president Mark Hall, he clarified that the company's gear is high tech RF for industrial controls, and it's not intended for a consumer audience. It uses 900MHz spectrum RF chirp communications to establish a low-bandwidth, high-reliability connection between industrial equipment (such as HVAC systems or electronic security gates) and their controllers. //

It's very nerdy-cool to see these things communicate underground, through trees and buildings, and up to a mile away. But unless you happen to be an HVAC or security system vendor, these particular RF chirp devices probably aren't going to be of any direct use to you. The underlying, nearly unjammable long-range technology could, however, lend itself to a lot of consumer-focused applications in the future—and the tech would do it without screwing up your Wi-Fi along the way. After a few makeshift at-home tests, we certainly hope to also see this kind of tech in drone controllers, security system sensors, and similar low-bandwidth applications in the near future

For years, NASB members have wanted to replace (or at least augment) the poor audio quality of analog SW with the crystal-clear sound of digital SW radio, specifically the Digital Radio Mondiale standard developed in Europe that is now being used in China and India.

“DRM sounds very much like FM, with a wide audio range and no static,” said Charles Caudill, president emeritus of World Christian Broadcasting, owner/operator of U.S. SW station KNLS. “It is also consistent: Either the DRM signal is received on your SW radio in full, or it isn’t. There’s no in-between.”

There are some DRM radios in use now, which is why some NASB members are offering limited DRM broadcasts alongside their regular analog SW transmissions.

“But the current generation of DRM SW receivers cost about $100 each, whereas you can buy a cheap analog SW radio for as little as $10,” said Dr. Jerry Plummer, a professor at Austin Peay State University in Clarksville, Tenn., and frequency coordinator for U.S. SW station WWCR. “Given that the audiences being targeted by NASB members are largely in the third world, the lack of inexpensive DRM receivers keeps them listening to analog shortwave.” //

Johannes Von Weyssenhoff was invited to speak at the annual meeting. Von Weyssenhoff said his StarWaves manufacturing firm (www.starwaves.de) has the technology, capability and existing prototypes to build DRM radios for $29 each, but only if the sale order is large enough to deliver economies of scale. (He also estimated $18 DRM modules could be built for installation in other radio models.)

“Twenty-nine dollars is doable at volumes staring at 30,000 receivers,” Von Weyssenhoff told Radio World. “Even smaller quantities would be possible at this price for very simple radios — for example, without graphics displays — but these would be special projects that had to be discussed individually. But even more advanced radios with Bluetooth or premium designs will be possible to offer at a reasonable price,” he said — as long as the sales orders was in the tens of thousands or more.

Liberia's media scene includes privately-owned and state-run outlets. Radio is the main news source and there is a lively commercial sector, especially in Monrovia.

There is a handful of TV stations, including a network run by state broadcaster LBS.

Most media outlets are not self-sustaining and rely on government advertising or support from politicians and international donors, says Freedom House.

There is real media freedom in Liberia, says Reporters Without Borders. But it says the authorities still threaten and intimidate journalists when they criticise the government.

Liberia enacted West Africa's first freedom of information law in 2010. However, large fines imposed in libel cases have encouraged self-censorship, says Freedom House.
Radio

• Liberian Broadcasting System (LBS) - state-owned
• UNMIL Radio - operated by United Nations mission
• ELWA - Christian
• Sky FM - private

70/7460-1L - Obstruction Marking and Lighting with Change 2

Date Issued
October 08, 2016
Responsible Office
AJV-1, Airspace Service
Description
This Advisory Circular (AC) sets forth standards for marking and lighting obstructions that have been deemed to be a hazard to air navigation. The change number and date of the change material are located at the top of the page. Advisory Circular 70/7460-1L is effective immediately.

“This is a NASA Spacecraft antenna. Its peculiar shape was designed by a computer. It's called an evolved antenna because it was designed a computer program that uses an evolutionary algorithm that mimics Darwinian evolution.”

Moscow, 4 August, 1945. The European chapter of World War Two was over, and the US and the USSR were pondering their future relationship.

At the American embassy, a group of boys from the Young Pioneer Organization of the Soviet Union made a charming gesture of friendship between the two superpowers.

They presented a large, hand-carved ceremonial seal of the United States of America to Averell Harriman, the US ambassador. It was later to become known simply as The Thing.

Naturally, Harriman's office would have checked the heavy wooden ornament for electronic bugs, but with neither wires nor batteries in evidence, what harm could it do?

Harriman gave The Thing pride of place, hanging on the wall of his study - from where it betrayed his private conversations for the next seven years.

He could not have realised that the device had been built by one of the true originals of the 20th Century.

Leon Theremin was famous even then for his revolutionary eponymous electrical musical instrument, which was played without being touched.

He had been living in the US with his wife, Lavinia Williams, before returning to the Soviet Union in 1938. His wife later said he had been kidnapped. In any case, he was promptly put to work in a prison camp, where he was forced to design, among other listening devices, The Thing.

Eventually, American radio operators stumbled upon the US ambassador's conversations being broadcast over the airwaves. These broadcasts were unpredictable: scan the embassy for radio emissions, and no bug was in evidence. It took yet more time to discover the secret.

The listening device was inside The Thing - and it was ingeniously simple, little more than an antenna attached to a cavity with a silver diaphragm over it, serving as a microphone. There were no batteries or any other source of power. The Thing did not need them.
It was activated by radio waves beamed at the US embassy by the Soviets. It used the energy of the incoming signal to broadcast back. When that signal was switched off, The Thing would go silent.

Much like Theremin's unearthly musical instrument, The Thing might seem a technological curiosity. But the idea of a device that is powered by incoming radio waves, and which sends back information in response, is much more than that.

The RFID tag - short for Radio-Frequency Identification - is ubiquitous in the modern economy.

My passport has one. So does my credit card, enabling me to pay for small items simply by waving it near an RFID reader.

Good software, not really… Usable software, yes. RF Analyzer and SDRtouch are two decent spectrum analyzers for Android. Both support the RTL-SDR and HackRF. There is also Avare ADSB for the RTL-SDR on Android.

Here we have the “RTL-SDR Blog v3” receiver, which is one of the most popular “next generation” RTL-SDR receivers. The plastic case has been replaced with an aluminum one that not only reduces interference, but helps the board dissipate heat while in operation. The crystal has been upgraded to a temperature compensated oscillator (TCXO) which helps reduce temperature drift. The R820T2 tuner is paired with a standard SMA antenna connector, and both it and the RTL2832U have some unused pins broken out if you’re looking to get into developing modifications or expansions to the core hardware. //

In the years since its inception, the RTL-SDR project has become the de facto “first step” for anyone looking to experiment with radio. It’s cheap, it’s easy, and since the hardware is incapable of transmission, you don’t have to worry about accidentally running afoul of the FCC or your local equivalent. Honestly, it’s difficult to think of a valid reason not to add one of these little USB receivers to your bag of tricks; even if you only use it once, it will more than pay for itself.

In England, Guglielmo Marconi began his wireless experiments in 1895, and on 2 June 1896 filed his provisional specification of a patent for wireless telegraphy. He demonstrated the system to the British Post Office in July. The British patent was accepted on 2 July 1897, and the US equivalent on 13 July 1897. In March 1896, Alexandr Popov demonstrated a similar wireless system in Russia, having demonstrated a more rudimentary system a year earlier.

Nobody can deny that shortwave goes beyond geographical, cultural, religious, political barriers, is free and can be consumed anonymously, which few platforms can claim nowadays. About 20 years ago, the BBC decided to cut its shortwave transmissions to countries such as the United States and other developed parts of the world, since these territories, or rather “markets” were served by FM and the internet etc. Other important international broadcasters, including Deutsche Welle, Radio Australia and Radio Exterior de Espana soon copied this model..

But the BBC kept shortwave for its large audiences in Africa and part of Asia. At the moment the major shortwave broadcasters are BBC, Voice of America, All India Radio, China Radio International, Radio Japan, Radio Romania, KBS Korea and Voice of Turkey and many more.

Twenty years after the first big blow to shortwave, this frequency band and its potential is being revisited. After all, not all the listeners in the world have broadband, smart phones, data plans, connected cars or enough disposable income. And analog radio in general continues to be resilient... //

In 2019 the BBC is still on shortwave and has large audiences in countries like Nigeria, having recently introduced new shortwave transmissions in additional languages. In Australia there was recently a wide consultation on the possible reintroduction of shortwave for the many Pacific islands depending on the services of Australian broadcasters, which had rushed to close down good shortwave facilities in the pursuit of internet and local digital. //

Digital Radio Mondiale was originally invented to offer medium (AM) and large coverage (HF) and the advantages of the good audio quality and extra multimedia services that can take shortwave into the 21st century. Maybe DRM was ahead of its time. The phasing in of digital broadcasts internationally was not in

tandem with the production and sale of receivers, which remains a regional and national business. Since its birth DRM has proven that it is a suitable option for shortwave offering an good digital quality of audio and even short live video at great distance without fading and crackly sound.

Now, at last, there are DRM receivers capable of receiving shortwave, there are broadcasts and interested broadcasters. Quietly and surely shortwave is being re-examined and appreciated for the quality of broadcasts and its potential as a “crisis radio” too. It can become crucial in emergencies when local and regional radio stations, satellite and internet may be off the air due to damage.

ENGLISH BAY, Ascension Island — A six-mile stretch of volcanic rock in the middle of the South Atlantic Ocean is home to the BBC’s Atlantic Relay Station.
Neale Bateman

Now managed and operated by Encompass Digital Media on behalf of the BBC World Service, the stations’ six powerful shortwave transmitters on Ascension Island beam program in a dozen or more languages to some 30 million listeners in north, west and central Africa.
The company’s engineers also run the island’s power station (consisting of five diesel generators and five wind turbines) as well as a reverse osmosis desalination plant, supplying electricity and drinking water to the island’s population of more than 800 people.n the mid-1960s, the BBC built a relay station at English Bay on the northern tip of the island to transmit shortwave radio broadcasts to Africa and South America, plus a power station to provide the electricity.

For more than 50 years, the Atlantic Relay Station has transmitted critical radio broadcasts to millions of listeners in some of the remotest parts of Africa. The daily broadcasts include transmissions in English, French, Arabic, Hausa, Somali, Swahili and several other African languages, and more recently has added transmissions for other international broadcasters as well as the BBC.

The shortwave transmitters include two 250 kW Marconi BD272 transmitters originally installed in 1966 (and still in daily use) and four 250 kW RIZ K01 transmitters, which are also capable of transmitting in Digital Radio Mondiale mode.

Each transmitter can be switched to one of more than 20 antennas, which consist of HF curtain arrays beaming toward target areas in Africa and South America. Programming from London is delivered via satellite, with resilience and backup feeds provided by Encompass. The power station is staffed around the clock with engineers taking remote control of the transmitter site outside of peak broadcast times.
Ascension typically transmits around 1,800 hours of program each month on shortwave for the BBC and other broadcasters. Most of these are beamed into Africa, but with the massive footprint of a shortwave transmission, some frequencies are also audible across much of Europe and the Middle East. Although the BBC closed its shortwave service for North and Latin America some years ago, the ability to transmit westward still exists.

links & listen online to worldwide radio stations