Wednesday, June 20, 2018

Morse Lives in Hollywood


Near Hollywood and Vine

Located in the center of Hollywood, near the intersection of Hollywood and Vine, stands a very recognizable landmark, a circular office building, the home of Capitol Records, 
It was built in 1956 and has the distinction of being the world’s first circular office building. The shape was chosen as it was more earthquake resistant and more efficient for heating and cooling.

Known as the ‘Sound Capitol of the World’, the building includes a sound-proofed chamber located 20 feet below ground designed by famed guitarist Les Paul. The first recordings made in the building were a series of instrumentals by Frank Sinatra titled “Frank Sinatra Conducts Tone Poems of Color”. Since then artists such as The Beatles, Beach Boys, Tina Turner, Steve Miller, Bonnie Raitt and others have recorded there.

Of interest to hams is the spire atop the building. It has a red light at the peak to comply with federal airline safety regulations. It blinks the word ‘Hollywood’ in Morse Code. In fact, the light’s initial activation on April 6,1956 was ceremoniously conducted by Leila Morse, granddaughter of Samuel Morse.

Only once in the building’s 50 year history was the message changed.  This occurred in 1992 when Capitol records celebrated 50 years in business. For the occasion the red light blinked ‘Capitol 50’ in Morse.

And while you're in that neighbourhood...


Disneyland - New Orleans Square: The telegraph office attached to the New Orleans Square Railroad Station replays a part of Walt Disney's Disneyland Opening Day Dedication in Morse code.

"TO ALL WHO COME TO DISNEYLAND, WELCOME. HERE AGE RELIVES FOND MEMORIES OF THE PAST, AND HERE YOUTH MAY SAVOR THE CHALLENGE AND PROMISE OF THE FUTURE."

Amateur radio operator George Eldridge helped restore the message in 1997. After taping the message, Eldridge discovered that it had been cut short. The telegram was improperly edited when Imagineers transferred the message from a continuously looping tape, to a digital recording. Thanks to Eldridge, the recording now plays the correct message.



Saturday, June 16, 2018

Multi-meters


A Communicator Reprise: February 2012


I’m sometimes surprised when a fellow ham asks a troubleshooting question and they have no knowledge of simple voltage, current or resistance measurement. When instructing the Basic course I used to spend a fair bit of time on series and parallel circuits and the means to make basic measurements, and there are several questions in the question bank that test these skills. I use my multi-meter several times a week, to check for a short, open circuit or even whether a dry cell battery requires replacement. This month we’ll look at the meters themselves… next month the basics of how to use them.
Multi-meters or multi-testers, also known as a VOM (Volt Ohm Meter) is an electronic measuring instrument that combines several measurement functions in one unit. They are inexpensive and very handy tools for measuring what is going on in a circuit and will offer Voltage, Current and Resistance ranges adequate for home use. Most new multi-meters are digital. Until recently, digital multi-meters were expensive, and some lab quality instruments still are, as much as $5,000. For as little as $10 you can purchase one on-line or on sale at Canadian Tire. The average home user can get by with a basic model. 

History

The first moving-pointer current-detecting device was the galvanometer in 1820. These were used to measure resistance and voltage by using a resistor bridge, and comparing the unknown quantity to a reference voltage or resistance. While useful in the lab, the devices were very slow and impractical in the field. These galvanometers were bulky and delicate. By adding a series or shunt resistor, more than one range of voltage or current could be measured with one movement.

Multi-meters were invented in the early 1920s as radio receivers and other vacuum tube electronic devices became more common. The invention of the first multi-meter is attributed to British Post Office engineer, Donald Macadie, who became dissatisfied with having to carry many separate instruments required for the maintenance of the telecommunications circuits. Macadie invented an instrument which could measure amperes, volts and ohms, so the multi-functional meter was then  named Avometer. The meter comprised a moving coil meter, voltage and precision resistors, and switches and sockets to select the range.
Any meter will load the circuit under test to some extent. For example, a microammeter with full-scale current of 50 microamps, the highest sensitivity commonly available, must draw at least 50 microamps from the circuit under test to deflect fully. This may load a high-impedance circuit so much as to affect the circuit, and thereby give a false low reading.

To eliminate loading, Vacuum Tube Voltmeters (VTVM) were used for voltage measurements in electronic circuits. The VTVM had a fixed input impedance of typically 1 megohm or more, usually through use of a vacuum tube input circuit, and thus did not significantly load the circuit being tested. Modern digital meters and some modern analog meters use electronic input circuitry to achieve high-input impedance—their voltage ranges are functionally equivalent to VTVMs. Before the introduction of digital electronic high-impedance analog transistor and field effect transistor (FETs), vacuum tubes were commonly used. 

How Does It Work?

An un-amplified analog multi-meter combines a meter movement, range resistors and switches. For an analog meter movement, DC voltage is measured with an internal series resistor connected between the meter movement and the circuit under test. If no resistors were used, the excessive voltage or current would quickly burn out the small wires that make up the meter coil. A set of switches allows greater resistance to be inserted for higher voltage ranges. As an example, a meter movement that required 1 milliamp for full scale deflection, with an internal resistance of 500 ohms, would, on a 10-volt range of the multi-meter, require 9,500 ohms of series resistance. Why? Remember Ohms Law, R = E / I or 10 volts divided by .001 amp which equals 10,000 ohms. The meter has an internal resistance of 500 ohms so we must add series resistance of 9,500 ohms to obtain a full scale reading. Now any voltage between 0 and 10 volts will produce some proportional deflection of the meter and this value can be read from the scale.  

For analog current ranges, low-resistance shunts are connected in parallel with the meter movement to divert most of the current around the coil. Again for the case of a hypothetical 1 mA, 500 ohm movement on a 1 Ampere range, the shunt resistance would be just over 0.5 ohms.

Moving coil instruments respond only to the average value of the current through them. To measure alternating current, a rectifier diode is inserted in the circuit so that the average value of current is non-zero. 

To measure resistance, a small dry cell within the instrument passes a current through the device under test and the meter coil. Since the current available depends on the state of charge of the dry cell, an analog multi-meter usually has an adjustment for the ohms scale to zero it, to compensate for the varying voltage of the meter battery. In the usual circuit found in analog multi-meters, the meter deflection is inversely proportional to the resistance; so full-scale is 0 ohms, and high resistance corresponds to smaller deflections. The ohms scale is compressed, so resolution is better at lower resistance values. Inexpensive analog meters may have only a single resistance scale, seriously restricting the range of precise measurements. 


Resolution of analog multi-meters is limited by the width of the scale pointer, parallax, vibration of the pointer, the accuracy of printing of scales, zero calibration, number of ranges, and errors due to non-horizontal use of the mechanical display. Accuracy of readings obtained is also often compromised by miscounting division markings, errors in mental arithmetic, parallax observation errors, and less than perfect eyesight. Mirrored scales and larger meter movements are used to improve resolution; two and a half to three digits equivalent resolution is usual and adequate for the limited precision needed for most measurements.

Analog meter movements are inherently much more fragile physically and electrically than digital meters. Many analog meters have been instantly broken by connecting to the wrong point in a circuit, or while on the wrong range, or by dropping onto the floor.
On the favourable side, Analog meters are able to display a changing reading in real time, whereas digital meters present such data in a manner that's either hard to follow or more often incomprehensible. Also a digital display can follow changes far more slowly than an analog movement, so often fails to show what's going on clearly. 
Analog meters are also useful in situations where its necessary to pay attention to something other than the meter, and the swing of the pointer can be seen without looking at it. This can happen when accessing awkward locations, or when working on cramped live circuitry.

Analog displays are also used to very roughly read currents well above the maximum rated current of the meter. For this, the probes are just touched to the circuit momentarily, and how fast the pointer speeds towards full-scale deflection is noted. This is often done when testing state of charge of dry batteries.
The ARRL handbook also says that analog multimeters, with no electronic circuitry, are less susceptible to radio frequency interference, important if working on radio gear.

Digital Meters

The first digital multi-meter was manufactured in 1955 by Non Linear Systems. Modern multi-meters are often digital due to their accuracy, durability and extra features. In a digital multi-meter the signal under test is converted to a voltage and an amplifier with electronically controlled gain preconditions the signal. A digital multi-meter displays the quantity measured as a number, which eliminates mechanical errors. Measurement enhancements available include:
Auto-ranging, which selects the correct range for the quantity under test so that the most significant digits are shown. For example, a four-digit multi-meter would automatically select an appropriate range to display 1.234 instead of 0.012, or overloading. Auto-ranging meters may include a facility to 'freeze' the meter to a particular range, because a measurement that causes frequent range changes is distracting to the user. Other factors being equal, an auto-ranging meter will have more circuitry than an equivalent, non-auto-ranging meter, and so will be more costly, but will be more convenient to use. An other reason to 'freeze' the range is that this somewhat avoids 'hunting' which is a situation where the meter continuously switches between two neighbouring ranges as when the instrument is in the low range, the value is too large but too small in the larger range.
Auto-polarity for direct-current readings, shows if the applied voltage is positive (agrees with meter lead labels) or negative (opposite polarity to meter leads).
Sample and hold, which will latch the most recent reading for examination after the instrument is removed from the circuit under test.

Current-limited tests for voltage drop across semiconductor junctions. While not a replacement for a transistor tester, this facilitates testing diodes and a variety of transistor types.

As you can see, not all meters are created equally and the choice depends upon your needs. For general home use however, a $10 digital multi-meter will accomplish most tasks with the least possibility of damage to the circuit or the meter.





Thursday, June 14, 2018

Community Involvement


Can we do more to preserve our hobby?



Amateur Radio has spectrum, a lot of it. We have frequencies from the low bands into the gigaHertz. The demands for commercial use are very great... and persistent. Frequency auctions often generate millions of dollars for government. 

I can't help but wonder if the current low use of some of our bands, particularly on VHF and 70cm will yield to pressure from commercial interests and be reduced to a smaller range of frequencies. There have been a number of articles written that wonder about the future of the hobby and our ability to draw in young Amateurs.

I believe that every Amateur has a responsibility to 'give back' to the community for the privilege of access to our spectrumI'm also a strong believer in exposing our hobby to the public - particularly the work Amateurs do in emergency response. Public demonstrations, science fairs, library and school visits have been well attended and receive favourable response locally.   'Spreading the word" will serve us well to gain public support when commercial interests come knocking.

~ John VE7TI 

Monday, June 11, 2018

Surrey Doors Open Observations


A peek behind our Operations and Training Centre Doors

This is a follow-up to post https://ve7sar.blogspot.com/2018/05/surrey-doors-open.html

This year 30 venues participated. Despite the prediction of rain, the skies cleared and we had a beautiful day. Opening was scheduled for 11am but our first visitor arrived at 10:20. The majority of our visitors arrived between 11am and 1pm and they not only seemed very interested in our demonstrations but complimented the volunteers and the role they play in the emergency program. From feedback, the hidden transmitter hunt was the most challenging, although the simulated contact and report emergency simulation was popular with kids who had not had any exposure to radio use. The most notable HF contact was with a commercial jetliner at 30,000 feet over Nebraska piloted by a ham. The adults were uniformly impressed by the technology Amateur Radio offers. I have no doubt that most, if not all, left with an appreciation of what Amateur Radio, and the OTC contribute to the City. Our exposure and feedback on social media was also uniformly positive. They included former Mayor Dianne Watts, a strong supporter of Amateur Radio.





We had one confirmed signup for the next Basic course, and a further three expressions of interest. The total for the day was 47 visitors.
My thanks to the following volunteers from SARC and SEPAR (most of whom wore two hats):

John VA7XB
Art VE7WAE
Robert VE7CZV
Don VA7GL
Pam VE7PFH
Michael VE7GMP
Robert VA7FMR
Jinty VA7JMR
Dixie VA7DIX
Lata VA7LVB
Kjeld VE7GP
David VA7DRS
Ron VE7VTA
Jeremy VE7TMY
Jason VA7IJT

Thank you all again!

John VE7TI
SDO Coordinator

Friday, June 1, 2018

The June 2018 Communicator Newsletter


Here is the latest Communicator 


In this edition you will find almost 50 pages of 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 directly from https://goo.gl/KRxhn8



As always, thank you to our contributors, and your feedback is always welcome. This is the last Communicator until September, as we take our usual Summer break.  My deadline for the September edition is August 20th. 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 the communicator@ve7sar.net

Have a great Summer and keep visiting this site for regular updates and news.

73,
John VE7TI
Communicator Editor


Wednesday, May 30, 2018

A LED Replacement Light For Your Soldering Iron



A Communicator Reprise: January 2012





One of handiest tools for the Ham Shack workbench is a Weller soldering gun.   It’s a 100 and 140 watt gun in a good old Bakelite case. This year it’s celebrating its 40th year on the work bench.  The thing  has been dropped so many times, it’s a miracle the gun still works, but thanks to several tubes of 5-minute epoxy and some crazy glue, it’s still in fine working condition.


But recently the little incandescent pilot lamp/tip illuminator burnt out and I just couldn’t find the right replacement bulb… a 2.0 volt bulb with a focusing lens at the end, something you used to be able to find in a common flashlight… a common flashlight 40 years ago. So while hunting in my parts bin, I came across a white light LED and decided to update the old gun with a modern light source.

So I removed the bulb from it’s screw base, found the right current-limiting resistor for 20ma at 2 volts and proceeded to assemble my new LED spot light.
There are a few things to ponder… the gun supplies 2v AC, your LED is a diode, so it’s going to work on one half the cycle, which translates into less light output…
Also the junction breakdown voltage is rather low on a LED, so if one were to use  higher AC voltages, it would most likely “expire” rather quickly.  But it’s only 2 volts, so I wasn’t worried.  You could put a 1N4007 in series on the other lead to help the LED deal with reverse voltages, but only if you were working with higher than 6-9 VAC.

So to hold things in place, I potted the resistor in epoxy putty, which set in 3 minutes and then soldered the LED to it.  I only had a ½ watt resistor, larger than I needed but it fit nicely in the screw base.  So if I wanted a 20mA current draw, that would be R = E / I = 2/.02 = 100 ohms and I just happened to have a 100 ohm resistor in my parts cabinet.  P (in watts) = E x I = 2 x .02 = .04 watts or 40 mW of heat dissipation so a ½ watt resistor wasn’t necessary, but it was the only size I have in stock and size wasn’t an issue.


A few minutes later I had a modern light source in an antique tool… but would it work?  But of course… for ½ the cycles per second -- so the light from it wasn’t as bright as I was hoping, but good enough to shed a bit of illumination on what was being soldered and certainly adequate for a pilot light to verify the gun was on.   OK for younger eyes, but this old buzzard needs a few more candle power!  Why didn’t I put a tiny bridge rectifier on the power leads to feed the LED with better DC?  Cause it was only a 2 volt tap off the coil inside the gun.. and for every diode you insert, you lose 0.7 of a volt.   Why did I need this in the first place you ask?  Well the tips of my fingers and tongue hadn’t recovered from my earlier attempts to see if the soldering tip was getting hot!  





Sunday, May 27, 2018

Marine Mobile...



A Communicator Reprise: January 2012


Most countries' amateur radio licenses allow licensed operators to install and use radio transmission equipment while at sea. Such operation is known as maritime mobile amateur radio. In most cases the operator's call sign needs to be extended by adding the suffix '/MM' when transmitting at sea.

There are some special considerations when installing and using amateur radio transmitters and receivers afloat. These include power supply, RF ground, antenna design and EMC (Electromagnetic compatibility) with other electronic equipment aboard.

For MF and HF use, the most common antenna design is to add two RF insulators into the backstay of the mast and feed it from the transceiver using a sintered bronze ground plate, bolted to the outside of the hull, well under the waterline, as a ground. On metal hulled boats the ground plate can be dispensed with, and the whole hull used for this purpose. In this case, the thickness of any paint layer is entirely negligible at RF. On a yacht with twin backstays, if insulators are placed in both of them and they are fed from the masthead, they may be usable as an 'inverted vee' avoiding the need to feed the antenna against ground. Either format will require the use of an ATU (Antenna Tuning Unit) to achieve resonance for the HF frequency in use, as the physical length of the antenna will almost invariably be incorrect at the frequency of choice. A few twin-masted sailing vessels have the space to erect a "Tee" antenna or an inverted "L" between masts. These antenna configurations are more common on merchant ships.

For VHF and UHF operation, one option is to mount a small yagi antenna to a pole 1–2 m (3–6 ft) long and haul this to the masthead using a flag halyard. If the halyard is correctly knotted to the middle and bottom of the pole, it is easy enough to make the antenna project above the clutter at the masthead into clear air. The problem is in rotating it - it usually needs to be lowered and re-raised to alter the direction of its beam. For the safety of masthead fittings and lights it is better if these yagis are light in weight and made largely of, for example, plastic tubes supporting internal wire conductors. Operating in this way is best reserved for when in harbour or at anchor, to avoid interfering with the operation of the boat. Repeated loss of signal due to rolling and pitching would make it impractical for useful communication at sea anyway.

For FM operation on the 2m band, the masthead vertical whip that is normally installed for marine VHF operation will provide good omni-directional, vertically polarized signals. The frequency of operation around 145 MHz is close enough to the antenna's design frequency of 156 MHz that most amateur transceivers will not need an ATU and will not suffer unduly from a poor (high) SWR.


Grounding

For a single-ended HF antenna, a good electrical ground connection is essential. It is also necessary from the points of view of safety and EMC considerations on any radio transmitter installation on a boat or ship. As mentioned above, metal-hulled vessels have a natural advantage in that, especially at HF and lower frequencies, the hull can be considered to be in contact with the water, as the insulating properties of the paint layer against the water is a capacitance that presents very little electrical impedance to the RF currents. For fibreglass and wooden hulls and HF transmission, the usual solution is to attach a sintered bronze plate to the outside of the hull for RF ground. The construction of a sintered bronze plate is porous to water so that although the plate may be only a square foot or two and an inch thick, the actual surface area of metal in electrical contact with the water is very many times that.

Once a good connection to the sea water has been established, it is necessary to make a good RF connection from the transceiver and/or the ATU to the grounding system. While it might seem that a good, thick wire is all that is needed, for large RF currents it is usually recommended that copper grounding tape is used. This is not because thick wires will not be able to support the currents involved, but because it is more likely that RF currents will remain flowing along something that has a wide surface area without re-transmitting themselves along the way due to skin effect. The key pathway from the ATU of a single-ended antenna system to the ground plate, or the hull ground-point, should be as short and as straight as possible. This should be considered from the start when deciding where to mount the various components within the hull. There is not much that the installer can do about the losses in, and the efficiencies of, the transceiver, the ATU, the antenna or its feed, but extra effort put into the efficiency of the ground paths will pay much bigger dividends, in terms of radiated power and freedom from EMC problems later, than any other single aspect of the installation. The salty sea makes an exceptionally good ground plane, and effort put into achieving a good connection to it will be handsomely repaid.


Going on a cruise?

You will first need the permission of the cruise ship company itself to even have an Amateur Radio transmitter in your possession while on board (whether in use or not).  So your first step is to make sure you have written authorization to have your radio with you.
Next, besides the company itself you will need to have permission of the ship's captain in order to use the radio.  Do not assume you can simply throw up a vertical outside of your stateroom and operate!

Once you have authorization to operate ship board, you still have to worry about reciprocal operating privileges with the country where your ship is, including territorial waters.

Canadian and US licensees need no special permit or authorization other than their own Industry Canada or FCC license and they stay within Canadian, US or International waters.  When an FCC licensed amateur is operating an amateur rig aboard a US-registered vessel in international waters, he or she must follow Part 97 of the FCC rules, particularly Section 97.11. 

If the ship is of foreign registry, you must obtain a reciprocal operating authorization from the country of registry in addition to being in compliance with Section 97.11. When amateurs enter the territorial waters of a country, they fall under their communications jurisdiction. This means that they must obtain the required reciprocal operating authorization. There are three such authorizations: CEPT which applies to most European countries and certain overseas territories; IARP which applies to certain countries in the America's; Reciprocal Permit which is available from most countries, but application must be made to the country and a fee paid.

In Canada, these permits may be obtained from Radio Amateurs of Canada (RAC) for a modest fee.






Friday, May 25, 2018

Contest Preparation Training

A Communicator Reprise: December 2011


Totally excellent fun!

Contesting is as close as you will get to conditions operating in an emergency. If you can effectively contest, you can pass emergency traffic. Therefore, this article is republished with an eye to the annual June Field Day. The contest training tips are valid and can be applied at the Surrey Amateur Radio Operational Training Centre (OTC). There are several Elmers within our group who would happily provide this training.

TRAINING PREPARATION

This event took an amazing amount of work to prepare for, but I believe we pulled it off very well and we're very happy with the results.  The next one will be a lot easier. John VA7XB, did a lot of agricultural work so that the seed of the idea of members turning out for operator training would fall on receptive ground.  How much fertilizer did he use?  I'm not going to go there.
Fred VE7IO opened his station for our use and revamped it to make it possible for the use of 2 radios at the same time. This required getting rid of all the junk on his office desk. Installed radios for the second op position. Added an 80m dipole up 100 ft to enhance the station low-band long distance (DX) capability. Totally changed his antenna switching system so that any antenna could be accessed by either op position and generated an op schedule.
Jim VE7FO, prepped and delivered a training session on logging SSB contacts on N1MM which included materials such that the trainees could practice at home - no radio required - before attending the actual operating event. Designed the new VE7IO antenna switching system.  Developed a Briefing Package and the plan for mentoring ops in the fine art of Search & Pounce and Running. 
This doesn't sound like much but it took us many full-time days. VE7IO and VE7FO shared the mentoring duties during the event.


THE PLAN

The purpose of the classroom style logging training was to enable trainees to get in some logging practice ahead of time so that they could more quickly develop the confidence to operate in Run Mode. The plan for the event itself was for the mentor to:-

  • Take the trainee through the Briefing Package.
  • Listen to actual contest QSOs taking place on the radio when going through the Running and S&P procedures.
  • Start the trainee making a few S&P contacts.
  • Just to get comfortable while the practice done at home kicks in.
  • Mentor to make a couple first.
  • Then get the trainee into Run mode.
  • Mentor to make a couple first.
  • The Mentor to provide reassurance and guidance as required.

RUNNING

A step-by-step guide to making contacts in Run Mode. Arranged in such a way as to make what the op needs to say at each step in the QSO very prominent while still providing basic info as to what's going on and how to log the QSO.


SEARCHING & POUNCING

Same idea as the Running info. I messed-up! Now what?
It's quite easy to make an error when entering the log info.  If you catch it as you make it it's easy to fix.  The further you are through the QSO the harder it gets. This section shows how to deal with each case. Things the op needs to do before actually operating.

  • Band map
  • Intro to packet cluster spots.
  • What it shows the op.
  • How to rapidly go to the frequency of a spotted station in order to work him.
  • How to use the spot colours to determine which ones to work first.
  • Phonetic Alphabets

Yes, that's plural.  The ISO (I think) standard phonetic alphabet pretty much sucks when signals are weak and interference is strong.  Three alternative lists are provided along with the standard.  However, it is recommended to only use the alternatives when the standard alphabet doesn't work.  (Don't want the EMCOMM folks to get into bad habits.)

  • Contest Rules

A copy of the official rules.

  • Antenna Switching Diagram

This shouldn't have been in the package as the ops are required to ask the Station Manager for permission to change antennas and it is the Station Manager's responsibility to change the switches to suit if he agrees that it would be a good thing to do.


WHAT ACTUALLY HAPPENED


LOGGING PRACTICE AT HOME

I meant to ask each one at the start of the event whether or not they had been able to but I forgot.  In any event, it looked to me as if most either didn't get the opportunity to do it or the practice methodology I proposed didn't work nearly as well as I thought it would.  I would be interested in hearing from anyone who did get some practice time in how much time they put into it and whether or not it helped.


THE EVENT

All my planning was based on the idea that I would mentor Friday evening and Saturday from 6 am until 5 pm, when I would go home, and Sunday from 9 am to the end and that VE7IO would mentor during the remaining time.
Well, I totally overlooked the fact that, because we had two op positions, we could have two ops starting at the same time.  Sure enough, right at the beginning of the event (1700L Friday) we had two ops show up on schedule and I hadn't put any thought into how I should deal with this.  I tried several approaches but only recall trying to have one log while the other operated.

So, a rather rough start and I apologize to the two who had to suffer through this.  Still, as I recall, once they got going on their own op positions things got better for them.  They did very well at working some pretty exotic DX.  Between them they worked Israel, China, Gambia, Madeira Islands, the Azores, Cape Verde, Philippines, South Cook Islands, Korea, Japan, Northern Mariana Islands, Guam, Aruba, Curacao, European Russia, Asiatic Russia, Kazakhstan, Antigua & Barbuda, Australia, Indonesia, Ascension Is, New Zealand, East Malaysia, Portugal, Germany, Spain, Ireland, France, Scotland, Italy, US Virgin Islands and Namibia.  Not bad for 5 hours of op time.
After that I only had one op to deal with at a time and things went much more smoothly.
Two of our ops who were to occupy the time from 9 am to the end at 5 pm were unfortunately unable to make it and I ended up with no one to mentor from noon to the end.

I thought I'd use the time to create some .wav files of the CQ, Exchange and Thank You messages.  N1MM can be set up to play these files at the appropriate times when you hit Enter.  This greatly reduces the strain on the op's voice.  Due to my unfamiliarity with the Micro-Ham interface between the computer and radio I was unable to get this to work so Fred and I spent the rest of the time discussing how things went and what we might change for the next time.


OBSERVATIONS

I was a little disappointed that very few ops actually got into Run mode.  After all, that was the point of the training session.  Still, I think everybody enjoyed the experience so I'm hoping they'll all be back for the next one (and most of them ready to get into Run mode after the first half hour or so).  The high bands were in terrific shape.  Best I've heard them in many years.

We tried to publish our score very frequently to the Getscores web site so that members could follow our progress.  Unfortunately, the site crashed 2 minutes after the start of the contest and stayed that way.  We didn't make my goal of 1,000 QSOs.  I'm sure we would have if we'd been able to get most people into Run mode.


HOW DID WE DO?


QSOs

We made 526 QSOs. This translates into 1259 QSO points.


MULTIPLIERS


  • We contacted 138 countries (you can count a country once for every band you work it on - our unique country total was 73)
  • We contacted 98 CQ Zones
  • Total multipliers = 236

SCORE

1259 QSO points X 236 Multipliers = 297,124

WHAT CHANGES WOULD I MAKE?

Very few. Some tweaking of the Briefing Package. More emphasis on getting ops into Run Mode. Don't schedule 2 newbies for the same time slot unless 2 mentors are available.

~ Jim Smith, VE7FO



Wednesday, May 16, 2018

Fraser River Freshet Emergency Activation


SEPAR Members Respond

The Fraser River is experiencing one of the largest flows in recorded history. Warm temperatures are accelerating the snow melt in the interior of the province. This could result in a once per hundred year flood. 


On Sunday May 13, Tuesday May 15 and Wednesday May 16, the Surrey Emergency Program - Amateur Radio (SEPAR) was activated by the Emergency Coordinator for the City of Surrey. We had a good turnout and I'd like to thank everyone that helped out at this activation.







We had a really good showing and Surrey Fire Service & the Surrey Emergency Program are happy with the help we provided. Also, a thanks to SARC for the use of the repeater.

This is a great example of how valuable SEPAR, as an integral part of the Surrey Emergency Program, can be. Other parts of Canada and the United States have the ARES program and those Amateur operators, while invaluable are not usually tied to the City, and are therefore not asked to volunteer for an activation that is not primarily communication oriented. SEPAR while we would like to have a communications component, is still available to the City, and BC (as City and Emergency Management BC volunteers). 

Personally I would like the City to continue to make use of us in times of need.

While this was not primarily a communications activation, we did find a way to make use of our ability to communicate by radio. Several times I was asked to confirm an issue from the command trailer and I was able to do that much faster than those that only used cell phones.  The times I did have an issue communicating, I could have resolved it without a cell phone call, had I remembered that we had designated a couple of simplex frequencies.

Below is a link to the BC River Forcast Centre for information about warnings, advisories and evacuation due to the freshet and flooding in British Columbia.
http://bcrfc.env.gov.bc.ca/warnings/index.htm




Monday, April 30, 2018

The May 2018 Communicator Newsletter


Here is the latest Communicator 

In this edition you will find over 40 pages of Amateur Radio News from the South West corner of Canada and elsewhere.

There are two interesting projects including a digital S-meter and an inexpensive, high amperage, variable power supply. You will also find tips and how-to's. You can download it as a .PDF file directly from https://goo.gl/w6CGZu

https://goo.gl/w6CGZu


The April Communicator made it to 5 continents. As always, thank you to our contributors, and your feedback is always welcome. My deadline for the June edition is May 25th. 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 the communicator@ve7sar.net


73,
John VE7TI
Communicator Editor




Friday, April 20, 2018

Modifying A Switching Power Supply Into A Variable Power Supply (A May Communicator Preview)


An Inexpensive Project To Power Your Amateur Radio (Or Other) Gear

By Daniel Romila VE7LCG

I was faced with a problem that many radio amateurs have: Getting a power supply capable of fulfilling my needs today and for the reasonable future. I decided that switching technology is the way to go, and that 12 Volts is my main voltage requirement. Regarding power, I was limited by my budget, because the more current a power supply can deliver, the more money I would have had to spend. I established 42 Amps would be enough, and that means 500 Watt capacity.

The above moment of decision was in 2016. So, now – in 2018 – I can tell you about the results of my selection of power supply and the modifications I made.

Whenever I was looking at eBay, Amazon and the Chinese websites (aliexpress.com, banggood.com, gearbest.com, etc), I was searching for 12V at 42A. 




The size of such a brick, at 12V and 42A is 115 x 215 x 46 (mm). The current price  around $38 CAD - about $29 US (shipping and taxes included).

I modified the circuit somewhat and replaced the trimmer resistor with a linear potentiometer. That extends the voltage range from the original 9 – 14 Volts to 4.5 – 15 Volts. Here is the result:


I successfully used this power supply for my Kenwood 7950 HF transceiver. I had very short power wires, so I put the power supply on top of the transceiver, on its speaker, because I use headphones... and there was no noise. I also used it for various audio experiments with operational amplifiers installed on a breadboard at around 30 cm from the switching power supply.

It ran cool, and despite my tries, I was not able to make this power supply run hot under various heavy loads. Under maximum power of a little less than 150 Watts. The fan starts to rotate automatically and it is silent.

A comparable digital power supply made for Amateur Radio would cost well over $150 CDN so this is a budget solution.

The full article is featured in the
May SARC Communicator






International Marconi Day - This Saturday




A 24-hour Amateur Radio Event


Amateur radios, point-to-point contacts, high-frequency transfers, a mysterious yet attractive prize for the most connected stations… All of this sounds like the beginning of a quirky B-movie. In reality, it is the essence of International Marconi Day, a 24-hour amateur radio event which celebrates the career of Italian wireless communications pioneer Guglielmo Marconi. 

Fitting with ‘The Rest Of The Story’ featured in the April 2018 Communicator, the event is held annually on the Saturday closest to to Marconi's birthday on 25 April 1874.  This year the contest runs on Saturday April 21st, operating hours are 0000 UTC to 2400 UTC (5pm Pacific time).

To commemorate the Nobel laureate’s achievements, fans use HF radio to make direct point-to-point contact between stations, relying on the same technology Marconi developed and utilized in his time. Although nowadays the Internet is the medium of choice for global communications, the idea behind International Marconi Day is to keep the spirit of invention alive. The event also provides an exciting throwback to the days when a connected planet Earth was but a bold dream and only a few exceptional people, such as Marconi, saw the value in it.



The organizers issue a very nice certificate for contacting 15 of 60 or more stations at significant sites around the globe related to Marconi's work.


At the time of writing, there are over sixty stations registered for the event. The full list, throughout Europe and North America is available at http://gx4crc.com/imd-stations/ 



Full details of the award and participating stations are available on the website gx4crc.com


Sunday, April 15, 2018

World Amateur Radio Day


The following information is courtesy of the

International Amateur Radio Union

Every April 18, Radio Amateurs worldwide take to the airwaves in celebration of World Amateur Radio Day (WARD). It was on that day in 1925 that the International Amateur Radio Union (IARU) was formed in Paris. Amateur Radio experimenters were the first to discover that the short wave spectrum — far from being a wasteland — could support worldwide propagation. In the rush to use these shorter wavelengths, Amateur Radio was “in grave danger of being pushed aside,” the IARU’s history has noted. Amateur Radio pioneers met in Paris in 1925 and created the IARU to support Amateur Radio worldwide.
Just two years later, at the International Radiotelegraph Conference, Amateur Radio gained the allocations still recognized today — 160, 80, 40, 20, and 10 metres. Since its founding, the IARU has worked tirelessly to defend and expand the frequency allocations for Amateur Radio. Thanks to the support of enlightened administrations in every part of the globe, Radio Amateurs are now able to experiment and communicate in frequency bands strategically located throughout the radio spectrum. From the 25 countries that formed the IARU in 1925, the IARU has grown to include 160 member-societies in three regions. IARU Region 1 includes Europe, Africa, the Middle East, and Northern Asia. Region 2 covers the Americas, and Region 3 is comprised of Australia, New Zealand, the Pacific island nations, and most of Asia. The International Telecommunication Union (ITU) has recognized the IARU as representing the interests of Amateur Radio.
Today, Amateur Radio is more popular than ever, with over 3,000,000 licensed operators!
World Amateur Radio Day is the day when IARU Member-Societies can show our capabilities to the public and enjoy global friendship with other Amateurs worldwide.

IARU has provided a poster for World Amateur Radio Day. Any club may download it and use it to promote WARD in their area. The poster comes in two sizes: 61cm x 91cm and a small (A4) flyer.

Groups should promote their WARD activity on social media by using the hash tag #WorldAmateurRadioDay on Twitter and Facebook. The IARU will list all WARD activities on the webpage. To have your WARD activity listed, send an email to IARU Secretary David Sumner, K1ZZ.

April 18 is the day for all of Amateur Radio to celebrate and tell the world about the science we can help teach, the community service we can provide and the fun we have.

We hope you will join in the fun and education that is World Amateur Radio Day!

For more information and to download a poster please visit the World Amateur Radio Day webpage at http://www.iaru.org/world-amateur-radio-day.html

Source: The International Amateur Radio Union


Alan Griffin
RAC MarCom Director

Thursday, April 12, 2018

Construct A $10 Dummy Load


A Communicator Reprise... October 2011


"I made this here dummy load and can’t figure out why I’m getting a 25:1 SWR!!”  “Got such great deal on this 100 watt 51 ohm resistor off of eBay and though it would make a great dummy load for the HF rig,” he beamed as handed me the homebrew project.  Did a nice job putting it into an aluminum project box, with both a UHF [SO-239] and a BNC connector...  


But of course the first giveaway was the aluminum encased resistor, the second was that it was 100watts in a relatively small package… When we hooked it up to the MiniVNA, and saw how it reacted to a sweep from 1 to 180 MHz., I could see then that it wasn’t your garden variety resistor, it was a wire-wound resistor – usually encased in an aluminum heatsink and a fraction of the size of a carbon composite resistor.  And boys and girls, what do we know about something that’s wound like a coil – an inductor?  Yessiree Bob… it’s an inductor. With enough wire to act like a proper load somewhere in the lower AM broadcast band.  So the closer to 1 KHz or DC, the better the SWR. So when he put 14.100 MHz into it, no wonder he measured 25:1!!  Of course the eBay seller didn’t say it was wire-wound and if you hadn’t seen one before, it just looked like a nice bright and shiny deal at $5.65.So, we chucked that experiment in the cylindrical file and proceeded to make him an inexpensive dummy load.


[Note: 3” discs would have been better in retrospect]
Here is what you need.  A paint can... you can buy new [and empty] for $1.36 at the local paint store.  A single hole SO-239 [$1], a piece of solid copper wire, two 2½” copper discs [in the photo] one has the drilling pattern already glued onto it and, twenty  5-Watt 1000 ohm carbon resistors.  Ceramic will do too… about $8 landed. 

The discs I cut from a piece of thin PCB, the resistors from eBay after I verified with the seller that they were not wire wound.  
After drilling the 22 holes in the discs and soldering all 20 resistors into place, one disc becomes the braid or shield side, the ground of the SO-239 and the piece of bare copper wire #10 or #12 bare copper goes from the centre pin on the connector to the disc on the bottom [of the photo].



The resistors were 5 watts, so 20 times 5 = 100 watts.
It gets hot enough in 30 seconds that you would not
be able to hold onto it for long.


What you have when finished  is 1000 divided by 20 or 50 ohms. But these are 5% resistors, and I didn’t ask for 20 hand measured resistors, so of course they were not all 1000 ohms or higher. All it takes is one to be 5% low and it brings the whole array down below 50 ohms. This one here measured 49.6 ohms. 


Close enough for its purpose.  Yes, this does present a small degree of capacitance and inductance – the discs do that, but it’s not enough to cause a problem.  







Hooked up to the MiniVNA and it was rather decent!  Not for 6 meters or higher, this was definitely a 1.8 to 30 MHz dummy load for under $10 in parts and about 2 hours of labour.  














The SWR didn’t change when put in the can with 1 litre of pure mineral oil from the drug store.  You could have used it as a dry load, but the oil makes it usable for minutes, rather than seconds and the paint can does reduce the RF radiated by roughly 60db.




As we can see from the sweep below, from 1.8 to 30 Mhz. the Impedance [green line] is pretty darn close to the 50 ohm reference line all across the entire HF band. The SWR 1.02:1 at 160 metres and about 1.26:1 at 30 MHz.  OK, not a perfect dummy load, but it costs less than $20, you can make it all at home and it does the job of giving your transceiver a non-radiating load for testing. The fancier commercial ones have LCR circuits incorporated in the array to compensate for the inductance and capacitance of the device – in other words, they doctor the load to get that perfect 1:1 across the band.











You can see  above, from 50 to 55MHZ, the SWR is about 1.3:1 across the six meter band, 
so it could be used if you needed to.  But by the time you get to the 2 meter band, it’s above 1.6:1 and not a good load. Thus commercial products tend to get more expensive at higher frequencies because you have to make them differently with higher tolerances, higher or more precise engineering and a few more parts to null out any inductive or capacitive reactance.

Next, the sweep below, from 1 MHz. to 180 MHz. is actually a good representation of most HF Cantennas, MFJ and other ‘non-VHF’ dummy loads.  The green line represents the impedance of the load.  From 1 to 21 Mhz. it’s pretty good at staying near 50 ohms and with an SWR of less than 1.1:1. But as you can see by the time it climbs out of the 30 Mhz section, the impedance drops and the SWR climbs, so by the time it reached 180Mhz., the limit of my MiniVNA,  it’s almost 2:1 with an impedance closer to 30 than 50 ohms.




This is mainly due to the construction of the dummy load, the 5% resistors soldered between two copper discs act somewhat like a capacitor, with the inductive reactance of lead lengths and 1¼ inches of #12 wire from the centre pin of the SO-239 and the lower disc, going through the centre of the discs, which must have some inductive quality. So not a perfectly symmetrical or resonant device, but as you have seen perfectly “HAM” in nature and quite adequate for the few times you need to test at full power without annoying others on the air.







CQ CQ CQ

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