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Friday, February 28, 2020

The March-April 2020 Communicator



Over 70 Pages Of Projects, News, Views and Reviews... 

Amateur Radio News from the South West corner of Canada and elsewhere. You will find Amateur Radio related articles, profiles, news, tips and how-to's. You can download it as a .PDF file from:  

http://bit.ly/SARC20MarApr


As always, thank you to our contributors, and your feedback is always welcome. The deadline for the next edition is April 21st.

If you have news or events from your Vancouver area club or photos, stories, projects or other items of interest from elsewhere, please email them to communicator@ve7sar.net

Keep visiting our site for regular updates and news: https://ve7sar.blogspot.ca    

73,

John VE7TI
'The Communicator' Editor




Sunday, February 23, 2020

A DMR Primer

Our meeting presenters say its the way of the future...

A recent SARC meeting featured two guests, Doug Pattengale VE7CQT and Brad Wilson VA7BWX, who have been heavily involved in local Digital Mobile Radio (DMR). They have kindly agreed to share their presentation slides. 

DMR is a limited open digital mobile radio standard defined in the European Telecommunications Standards Institute (ETSI) Standard TS 102 361 and used in commercial products around the world. In the commercial world, DMR, along with P25 phase II and NXDN are the main competitor technologies in achieving 6.25 kHz equivalent bandwidth using the proprietary AMBE+2 vocoder. DMR and P25 II both use two-slot TDMA in a 12.5 kHz channel, while NXDN uses discrete 6.25 kHz channels using frequency division and TETRA uses a four-slot TDMA in a 25 kHz channel.

DMR was designed with three tiers. DMR tiers I and II (conventional) were first published in 2005, and DMR III (Trunked version) was published in 2012, with manufacturers producing products within a few years of each publication.

In our Amateur Radio world, DMS is one of three main digital radio technologies, with iCom D-Star and Yaesu System Fusion as earlier players.




The primary goal of the standard is to specify a digital system with low complexity, low cost and interoperability across brands, so radio communications purchasers are not locked into a proprietary solution. In practice, given the current limited scope of the DMR standard, many vendors have introduced proprietary features that make their product offerings non-interoperable with other brands.









To view or download the presentation, visit:
https://drive.google.com/file/d/1f9U1mXGQ6nOuE_umJCsPSIPiep-LLieD/view?usp=sharing

Our thanks to Doug and Brad for an informative evening.



Thursday, February 20, 2020

LED Street Light Replacement

 

Will we soon have more RFI noise to deal with?


Our local electrical supplier, BC Hydro, says it may begin installing thousands of light emitting diode (LED) street lights across the province this summer.

The utility currently owns and maintains approximately 95,000 streetlights around the province, roughly 30 per cent of all streetlights in British Columbia. Most of the ones attached to BC Hydro's electricity poles are high pressure sodium (HPS) lights.

Hydro says: "LED lights are known to last longer, are brighter and render colours significantly better than HPS lights."

The transition to the energy-saving technology could lead to cost savings of 50 to 70 per cent for the smaller communities who rely on the utility's public lighting, according to the Union of B.C. Municipalities (UBCM).

As taxpayers we're certainly in favour of lower costs but, you have only to run a Google search to learn that, in other areas, Amateurs have expressed concern that these lights may contribute to an  increase in RF interference across the spectrum., specifically in the HF bands (below 30 MHz).

In some cases this is apparently due to inadequate shielding, poor quality, or lack of components to reduce noise, but it is generally agreed that the electronic power supplies in LED street lights can be the culprit.
Here are some of the story links:

CBC News 

ABC News Toledo, OH 

NBC Philadelphia

RAC, are you monitoring this?

________________________________

Shortly after this story appeared on our blog page, Keith Whitney VE7KW, RAC Director BC & Yukon, responded. It shows that RAC has taken notice:

I appreciate your concern, but would like to make a couple of points.

  • RAC monitors this through the RABC (Radio Advisory Board of Canada) EMC Committee.
  • The relevant regulation is ICES-005 Lighting Equipment last updated in December 2018 which sets limits on conducted (HF) and radiated (VHF) emissions. Note the LED limits are lower than the Gas Discharge (Sodium light) limits.
  • Section 4(3) of the Radio Communications Act states that

"No person shall manufacture, import, distribute, lease, offer for sale or sell any radio apparatus, interference-causing equipment or radio-sensitive equipment for which technical standards have been established under paragraph 6(1)(a), unless the apparatus or equipment complies with those standards."

It is to be assumed that a public utility would be compliant.

My personal experience indicates this is not a major problem. 

  • I follow the RSGB EMC reports and am not aware that approved LED lighting has been identified as a problem.
  • I do a lot of contesting from VE7SCC which uses LED lighting almost exclusively in the shack and monitors for noise with an SDR. The site (Riverview Hospital) changed over to LED street lights about 18 months ago with no noticeable noise increase.
  • I have just come from V3T (Belize) where the 80 through 15m noise levels were some of the lowest I have seen despite the entire resort using LED lighting as well as the Town we overlooked using LED street lamps. 

Nothing in the field of EMC is guaranteed and this will merit ongoing monitoring. I would encourage people with access to an SDR to take a wide band “reference noise spectrum” now for comparison later. It would be particularly useful if they turn off their house power to prove that the noise source(s) are external.

~ 73 Keith VE7KW
   RAC Director BC and Yukon







Thursday, February 13, 2020

Internet Security For Amateurs



Yes, we're susceptible to malware with all these new connected gadgets!


At our February 2020 general meeting we had a guest speaker who is an internationally regarded expert on Internet security. For the past 20+ years, Hardeep Mehrotara has worked for the military, law enforcement and news organizations. He has co-
authored several books on critical controls and security benchmarks, and has participated in hacking operations to test system security. Best of all, he is also a Ham operator as VA7HKM.

The discussion points from the presentation covered
  • What is cyber security?
  • Importance of cyber security in amateur radio
  • evolving cyber security threats
  • practice basic cyber hygiene
He covered the importance of Ham radio and internet, our modern digital technology, which more and more is connected to the Internet. Many transceivers and their accessories have some type of Internet connection, particularly remotely controlled radios.

Cyber security refers to combination of people, process and technology designed to protect inter-connected networks (e.g. Internet), devices, programs, and data from attack, damage, or inappropriate or unauthorized access. 

Cybersecurity consists of three key pillars:




Importance of cyber security in amateur radio


  • Denial of service on ham radio networks.
  • Hacking of Software defined radios.
  • Malicious control of remote devices.
  • Impact on Internet-Of-Things (IoT) devices.

Threat actors





Evolving cyber threats include


  • Phishing
  • Third party email compromises
  • Ransomware
  • IoT based attacks


Phishing and Third party compromised email. ARRL warned about this to their members with an xxx.arrl.net forwarding address





Ransomware 

Also a real threat and you should keep a separate backup as a precaution.




Practicing basic cyber hygiene

  • AVOID OLDER OPERATING SYSTEMS!  For example, Windows 7 is no longer supported.
  • ALL operating systems are at risk, including Mac and Linux
  • Install a reputable anti-virus and firewall
  • Patch your systems regularly
  • Use strong passwords and do not re-use passwords
  • Use multi-factor authentication where possible
  • Encrypt your sensitive information
  • Backup your information
  • Be cautious when you click on links on websites, emails, social media

Cyber Threat Predictions

As technology progresses, so will the threat.




See Hardeep on a news presentation on cyber security threats
https://globalnews.ca/video/5974584/protecting-small-businesses-from-cyber-security-threats/ 

The slides of Hardeep's presentation are at:







Revisiting An Old Grid-Dip Meter


Older technology still works...

August 2017

Recent talk about how to test traps on a multi-band antenna got me thinking about the venerable “grid dip meter”.  After a VOM and antenna analyzer, a dip meter is one of the most useful instruments you might think of acquiring for your ham shack, especially if you like to experiment and trouble-shoot. 

Of course, the term “grid dip” is obsolete as it refers to the earliest version of the instrument which used vacuum tubes whose grid current dips when its L-C circuit is coupled to an external resonant circuit.  The idea is that if you wish to measure the resonant frequency of a tuned circuit, you put the meter near to the circuit under test so the coils are inductively coupled and note the frequency at which the meter shows a dip. Simple!  Nowadays, of course, solid state circuits replace the vacuum tube oscillator.
Only problem is that these instruments are not, by nature, very accurate so the exercise can often lead you in the right direction but may not be sufficiently precise for your needs.  This was my situation circa 1972  when I was constructing a 5-band single conversion HF receiver as part of my aspiration to have a 100% home brew station (I never actually got there) but I had no way of aligning it. In fact, the receiver appeared to work but I couldn’t hear any signals where they were supposed to be.  The receiver had a 9 MHz IF and utilized a 9 MHz SSB crystal SSB filter, which was somewhat of a departure from the conventional design in those days.  In order to tune the amateur bands, the 5-5.5 MHz  signal from the VFO was mixed with a band switched crystal controlled oscillator to create the 9 MHz IF. 






Along came a circuit in QST that described a “crystal calibrated solid state dip meter” – just the ticket for me.  A crystal is nothing more than a physical manifestation of a resonant circuit as the crystal oscillates at a unique frequency (plus harmonics).  This interested me because  I had a variety of crystals on hand.  I could calibrate with both the crystal’s fundamental frequency and several of its harmonics.

I suspected the VFO in my receiver was not tuning exactly 5.0-5.5 MHz as designed.  This turned out to be the case, and by calibrating the meter with my supply of crystals to create an accurate calibration curve, my home-made dip meter was sufficiently accurate that I could adjust the L-C circuit and – voila! – I could now bring in the ham bands.

After the receiver, I went on to construct an electronic CW keyer, then a 2-band 20/80 m transmitter using the same fundamental concepts as the receiver but, alas, this last project was never completed.  By the mid 1970’s it was apparent that tube gear was on the way out, so I abandoned the projects and the parts fill my junk box.  Nowadays, calibrating the grid dip meter would be done a different way… just listen for the oscillator signal on your receiver to determine its frequency.  But the usefulness of a dip meter has not changed.  It will tell you the resonant frequency of an L-C circuit and, if the L value is known, it will tell you what the C value is (or vice versa) by simple formula which relates the 3 variables in the formula below. 


 ~John VA7XB





Sunday, February 9, 2020

What Is The Origin Of Ham?


Lots of theories...

I was asked by one of our current Basic class students about where the term ’Ham’ originated.  I’ve probably heard as many theories and myths as anyone but, if you search the Web for the origin of the term "HAM" for radio amateurs, you will find two or three accounts that are believable. The most common, and the one to which I ascribed to for many years was that it referred to ‘Ham-fisted (clumsy) CW operators’.

Why radio amateurs are called HAMS (from Florida Skip Magazine - 1959)
Have you ever wondered why radio amateurs are called "HAMS?" Well, it goes like this: The word "HAM" as applied to 1908 was the station call of the first amateur wireless stations operated by some amateurs of the Harvard Radio Club. They were Albert S. Hyman, Bob Almy and Poogie Murray. 

At first they called their station "HYMAN-ALMY-MURRAY". Tapping out such a long name in code soon became tiresome and called for a revision. They changed it to "HY-AL-MU," using the first two letters of each of their names. Early in 1901 some confusion resulted between signals from amateur wireless station "HYALMU" and a Mexican ship named "HYALMO." They then decided to use only the first letter of each name, and the station call became "HAM." 

In the early pioneer days of unregulated radio amateur operators picked their own frequency and call-letters. Then, as now, some amateurs had better signals than commercial stations. The resulting interference came to the attention of congressional committees in Washington and Congress gave much time to proposed legislation designed to critically limit amateur radio activity. In 1911 ALBERT HYMAN chose the controversial Wireless Regulation Bill as the topic for his Thesis at Harvard. His instructor insisted that a copy be sent to Senator David Walsh, a member of one of the committees hearing the Bill. The Senator was so impressed with the thesis is that he asked Hyman to appear before the committee. Hyman took the stand and described how the little station was built and almost cried when he told the crowded committee room that if the Bill went through that they would have to close down the station because they could not afford the license fees and all the other requirements which the Bill imposed on amateur stations. 

Congressional debate began on the Wireless Regulation Bill and little station "HAM" became the symbol for all the little amateur stations in the country crying to be saved from the menace and greed of the big commercial stations who didn't want them around. The Bill finally got to the floor of Congress and every speaker talked about the "...poor little HAM station.” That's how it all started. Nation-wide publicity associated station "HAM" with amateur radio operators. From that day to this, and probably until the end of time in radio an amateur is a "HAM."

Is it true? The facts are difficult to verify. Wiki calls it a “widely circulated but fanciful tale,” and the 1909 Wireless Registry, May edition listed Earl C. Hawkins of Minneapolis, Minnesota, as operating with the callsign "H.A.M."   You decide which origin to believe.

~ John VE7TI 
 Communicator Editor

Thursday, February 6, 2020

Thunderstruck: A Novel



This is a 'who-dunit' with a radio twist...

In the May 2017 Communicator we wrote in QRM about Marconi and Maskelyne, and their attempts to discredit each other. There was mention of a book, ‘Thunderstruck’ written by Erik Larson.

Erik Larson tells the factual and interwoven stories of two men, Hawley Crippen, a very unlikely murderer, and Guglielmo Marconi, the obsessive creator of a seemingly supernatural means of communication, and how their lives intersect during one of the greatest criminal chases of all time.

Set in Edwardian London and on the stormy coasts of Cornwall, Cape Cod, and Nova Scotia, Thunderstruck evokes the dynamism of those years when great shipping companies competed to build the biggest, fastest ocean liners, scientific advances dazzled the public with visions of a world transformed, and the rich outdid one another with ostentatious displays of wealth. Against this background, Marconi races against incredible odds and relentless skepticism to perfect his invention: the wireless, a prime catalyst for the emergence of the world we know today. Meanwhile, Crippen, "the kindest of men," nearly commits the perfect crime.

With superb narrative skills, Erik Larson guides these parallel narratives toward a relentlessly suspenseful meeting on the waters of the North Atlantic. Along the way, he tells of a sad and tragic love affair that was described on the front pages of newspapers around the world, a chief inspector who found himself strangely sympathetic to the killer and his lover, and a driven and compelling inventor who transformed the way we communicate. Thunderstruck presents a vibrant portrait of an era of séances, science, and fog, inhabited by inventors, magicians, and Scotland Yard detectives, all presided over by the amiable and fun-loving Edward VII as the world slid inevitably toward the first great war of the twentieth century. Gripping from the first page, and rich with fascinating detail about the time, the people, and the new inventions that connect and divide us, Thunderstruck is splendid narrative history from a master of the form.
An excerpt:

“One night, during a storm, an engineer named W. W. Bradfield was sitting at the Wimereux transmitter, when suddenly the door to the room crashed open. In the portal stood a man disheveled by the storm and apparently experiencing some form of internal agony. He blamed the transmissions and shouted that they must stop. The revolver in his hand imparted a certain added gravity. Bradfield responded with the calm of a watchmaker. He told the intruder he understood his problem and that his experience was not unusual. He was in luck, however, Bradfield said, for he had “come to the only man alive who could cure him.” This would require an “electrical inoculation,” after which, Bradfield promised, he “would be immune to electro-magnetic waves for the rest of his life.” The man consented. Bradfield instructed him that for his own safety he must first remove from his person anything made of metal, including coins, timepieces, and of course the revolver in his hand. The intruder obliged, at which point Bradfield gave him a potent electrical shock, not so powerful as to kill him, but certainly enough to command his attention. The man left, convinced that he was indeed cured.”

Erik Larson is the author of three other national bestsellers: In the Garden of Beasts, The Devil in the White City, and Isaac’s Storm, which have collectively sold more than 5.5 million copies. His books have been published in seventeen countries and are widely available in print, digital and audio formats.

Aside from being an interesting ‘who-dunit’, it is also a story with enough technical detail that it will interest those in the Amateur Radio community.




CQ CQ CQ

The March-April 2020 Communicator

Over 70 Pages Of Projects, News, Views and Reviews...  Amateur Radio News from the South West corner of Canada and elsewhere. You will f...

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