Our Basic Amateur Radio Course... Interrupted!

Looking for 'novel' new ways to present our material

At the beginning of March, due to the Novel Corona Virus, we suddenly found ourselves without our Surrey Fire Services Training Centre classroom. We were in week 3 of our 9 week Basic course and just finishing up a CW course.

Our usual classroom

For several years we successfully used Microsoft OneDrive as a means to distribute pre-reading and other course content to our students but continuing on-line instruction needed a more complete solution.

I started to investigate popular multimedia conferencing solutions to try to find a way to continue instruction. My criteria were:

• Free or inexpensive
• Accessible by computer on multiple operating systems (preferably web browser based so there is no software download or installation required)
• Allow up to 30 (perhaps more) subscribers
• Have a master ‘host’ control to talk, show PowerPoint slides and video
• Allow participant questions
• Allow at least 2-3 hours per session

There were 50 or so options, but many only had a short, free trial period that limited time, resources or users.  Then I found the open source BigBlueButton and it's associated conference site Canvas. These two resources are used extensively by universities and other remote teaching institutions. It proved to meet my criteria and much more.

I have spent the last two weeks entering material, including PowerPoint slides, video links and questions from the Canadian Basic Amateur Radio Question Bank. The latter is accessible by our students to complete quizzes after the lesson has been presented. It scores and offers a review of wrong answers to questions. There are built-in assignment, announcement and file server features. 

This past Tuesday evening we had our first conference and presented our week 4 program. Students accessed securely on a number of different devices. As long as you have browser access on a reasonably good Internet connection it works flawlessly. All went smoothly and our PowerPoint material, including animations and video came through without a hitch. Students were able to comment by audio or the included scratchpad feature, and questions were answerable while the presentation was running. Student feedback was universally positive: "Much better than travelling to a classroom." You can also record the session so students can review it within 14 days, before it is erased.

Our BigBlueButton/Canvas Classroom

I can't say how pleased I am with this package. Now that the material is entered we can conceivably offer our highly rated course throughout the country by remote access, a boon to those not normally near a training location.

The course goes on!

~ John VE7TI

Update May 2020:

The course was completed without further interruption with glowing feedback at the conclusion. One student wrote: "Great course, this turned out better than expected. I could stay home during the presentations, in my easy chair, in my PJs with my iPad and a cup of tea."

At the conclusion of the course, students successfully wrote the exam in small groups at covered picnic tables in a local park, maintaining appropriate physical distancing.

We plan to offer another course in mid to late September 2020. It will be in the classroom unless the COVID situation requires us to present it on-line again. Either way, we're confident we have the capability.

~

Fox Hunting

Also known as Amateur Radio Direction Finding (ARDF)

Another Great Meeting Presentation

Amateur radio direction finding (ARDF, also known as radio orienteering, radio fox hunting and radiosport) is an amateur radio sport that combines radio direction finding with the map and compass skills of orienteering. It is a timed race in which individual competitors use a topographic map, a magnetic compass and radio direction finding apparatus to navigate through diverse wooded terrain while searching for radio transmitters. The rules of the sport and international competitions are organized by the International Amateur Radio Union. The sport has been most popular in Eastern Europe, Russia, and China, where it was often used in the physical education programs in schools.

ARDF events use radio frequencies on either the two-meter or eighty-meter amateur radio bands. These two bands were chosen because of their universal availability to amateur radio licensees in all countries. The radio equipment carried by competitors on a course must be capable of receiving the signal being transmitted by the five transmitters and useful for radio direction finding, including a radio receiver, attenuator, and directional antenna. Most equipment designs integrate all three components into one handheld device. (See Wikipedia and HomingIn for additional details) 

Receiver equipment

No radio license is required. The radio equipment carried on course must be capable of receiving the signal being transmitted by the transmitters and useful for radio direction finding. This includes a radio receiver that can tune in the specific frequency of transmission being used for the event, an attenuator or variable gain control, and a directional antenna. Directional antennas are more sensitive to radio signals arriving from some directions than others.

Most equipment designs integrate all three components into one handheld device. On the two meter band, the most common directional antennas used by competitors are two or three element Yagi antennas made from flexible steel tape. This kind of antenna has a cardioid receiving pattern, which means that it has one peak direction where the received signal will be the strongest, and a null direction, 180° from the peak, in which the received signal will be the weakest. Flexible steel tape enables the antenna elements to flex and not break when encountering vegetation in the forest. 

On the eighty meter band, two common receiver design approaches are to use either a small loop antenna or an even smaller loop antenna wound around a ferrite rod. These antennas have a bidirectional receiving pattern, with two peak directions 180° apart from one another and two null directions 180° apart from one another. The peak directions are 90° offset from the null directions. A small vertical antenna element can be combined with the loop or ferrite rod antenna to change the receiving pattern to a cardioid shape, but the resulting null in the cardioid is not as sensitive as the nulls in the bidirectional receiving pattern. A switch is often used to allow the competitor to select the bidirectional or cardioid patterns at any moment. ARDF receiver equipment is designed to be lightweight and easy to operate while the competitor is in motion as well as rugged enough to withstand use in areas of thick vegetation.

Les Tocko VA7OM has designed a top notch contest grade ARDF 80m receiver that has now gone into production. It is hoped that it will be available for our annual SARC FoxHunt in May. Once sufficient quantities are in stock they will be available for general purchase. Inquiries may be sent to VA7XB@rac.ca.

Les presented a club meeting program on ARDF and the receiver on March 11, 2020, along with his cohorts Amel Krdzalic VA7KBA and Dave Miller VE7HR. He has shared his presentation slides and two videos.

Les' Slides on ARDF (PDF 5Mb) or Les' Demo with Video (PPS 170Mb)

Les' ARDF Video: Fox Placement and Strategy

A video on the use of the receiver

Our 2019 SARC FoxHunt video

Update!

Our next Fox Hunt was scheduled for May 9th, however it was postponed due to the COVID crisis. The new date is Saturday, August 29. Here is the poster:

~ Updated 2020-08-12

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

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.

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

_______________________________________


March 11, 2020 - More Good News:

Here’s my experience with LED street lights. 

While working in my front yard last week, I noticed a contractor’s vehicle with lift crane parked in the street, while some work was being undertaken at the street lamp fixture.  When the contractor moved up to my QTH, I spoke with him and asked him what he was doing.  He was very friendly and advised that he was changing out the sodium mercury lamps for LEDs.  When I expressed my concern about this because I had been hearing stories of RFI from LEDs affecting HF reception, he asked me what I knew about it.  I told him briefly that I was no expert, but would welcome the opportunity to do some testing before and after turning the LEDs on.  He agreed readily.  I am very fortunate to be in a low RFI neighbourhood, with virtually S-0 noise on 20m and up, and only S5 noise on 40m, and I hope to keep it that way.

So I did 2 things: 
1) Turned my beam to point directly at the installation with the receiver on 20 m; and 
2) I brought out my 80 m “Tocko” foxhunt receiver.  

I was pleasantly surprised to find no change on the receiver noise level, and no response when pointing the foxhunt sense antenna at the lamp, either before or after the LEDs were turned on.  I will continue to monitor to see if anything changes but at least at this time, I find no reason to complain about the LEDs on our street.  Both the contractor and I went away happy.

~ JB VA7XB

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:

https://drive.google.com/file/d/1iT93R0G3jCyuJllQ7eGFCek2g6sBQhWC/view?usp=sharing 

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