Tuesday, September 18, 2018

Reflecting On The Summer Forest Fires


Over 500 Forest Fires

The Largest, Longest, Most Expensive Fire Season Ever


In the Greater Vancouver area, we have not had to endure any evacuations due to the fires that are plaguing much of our province and even into the USA. The smoke in our area gives us some impression of how bad the forest fires must be.  The Province of BC declared a state of emergency August 16th 2018 and there were about 560 fires burning in our province alone. For a short stretch, the news reported, that we had the worse air quality in the world.




There has not, to my knowledge, been a need to activate any Emergency Communications Teams due to the fires. That doesn’t mean that there isn’t the real possibility that there could be activations for forest fires. 

The Colorado forest fires in July 2012 saw ARES teams in Colorado County called out to communicate at a number of fires. In Arizona this year, the ARES group in Coconino County was called to action because of poor cellular communications to the front line of the forest fires. In 2016, in Tennessee, ARES bridged the communications gap for the Red Cross during the wildfires there. In California in 2015, during the wildfires there, ARES volunteers in Amador,  Yolo and Sacramento Counties were activated to assist the Red Cross. 

In 2016, New Mexico Volunteers were also activated during wildfires in that state.
It’s pretty unlikely that we’ll be called to action for a wildfire in the Greater Vancouver area. It is a real possibility for other areas of the province however. When a disaster happens close to home, it makes people think about disasters, so it’s a good time to think about your preparedness status. 

If you are reading this and don’t know how to prepare (hopefully you aren’t a Surrey Emergency Program Amateur Radio (SEPAR) member because all our members should be ready), there are lots of places online that can give you ideas of what you need to do.  Preparedness is a little different for everyone, depending on your personal needs. A good place to start is:

https://www2.gov.bc.ca/gov/content/safety/emergency-preparedness-response-recovery/preparedbc

Get Prepared!

SEPAR Annual Competition


As of last April, we started a competition that active SEPAR members can participate in. The most active member will win an MD390 DMR Radio package. You can checkout pictures of the radio and see the rules on http://va7.ca/radio (an interim website).
If you are not now a member, we’d love to have you on-board. Contact me at the  link above.

~ Roger VA7VH
   SEPAR Coordinator




Friday, September 14, 2018

About Microphones



A Communicator Reprise: September 2012

A Primer On Mics For Ham Radio

All Hams use them as a basic piece of operating equipment but most never give it a second thought—the microphone.

A microphone colloquially called a mic or mike is an acoustic-to-electric transducer or sensor that converts sound into an electrical signal.


Both Thomas Alva Edison and Emile Berliner filed patent applications for the carbon microphone, in March and June 1877 respectively. After a long legal battle, Edison emerged the victor, and the Berliner patent was ruled invalid by both American and British courts. 

There are basically two kinds of microphone technology, dynamic and condenser.
Dynamic mics are actually backwards speakers and generate a small amount of electricity when the diaphragm of the mic moves back and forth under the pressure of the sound waves hitting it.

Condenser mics are powered or biased by electricity and so are more sensitive; they use a more lightweight diaphragm and are better at picking up nuances of sound. "Large diaphragm" condenser mics are more sensitive and more expensive than "small diaphragm" types. 

Pickup Patterns isn't what you get when you drive your truck in circles in the snow, but refers to the relative sensitivity of a microphone to sounds coming from the side. A pickup pattern can be… 

Omnidirectional picks up equally well in all directions
Unidirectional picks up mostly from one direction
Cardioid picks up in a heart-shaped pattern (hey, you think your dad was kidding when he said studying Latin would come in handy sometime?) 

Exotica ribbon mics, tube mics, and most other technologies are probably way out of your budget anyway… except for the PZM (Pressure Zone Microphone), which is patented by Crown and was used by Radio Shack for many years. The current Radio Shack mic is not considered to be much good, but if you can find one of the older ones, you can modify it for serious use.

Plugs everyone is used to teeny little 1/8" plugs found on consumer mics, 1/4" plugs found on guitar cables or the little square plastic ones on your transceiver mic  that look like an over-sized telephone plug. Forget all that. Professional mics have XLR plugs and balanced cables, which have the following characteristics.

The plugs lock in and don't rip out easily when someone trips over something.
the cables have three conductors, which not only make them thicker and more resistant to rough handling, but also means that they're less likely to pick up buzz, hum, etc.

Balanced vs Unbalanced

An unbalanced audio path has two conductors. One carries the audio signal and the other is the shield/ground. There is nothing at all wrong with an unbalanced signal but at times can be susceptible to picking up interference from radio frequencies or electro magnetic fields causing noise and buzz and picking up the occasional unwanted radio station! In fact, a lot of gear is unbalanced on the inside even though it has a balanced input and output. Including some high end consoles. 

A balanced signal has three conductors. It relies on a sum and difference principal. 
Sum and difference is the combining (summing) of two signals that are out of phase from each other. Whatever doesn't cancel out is what you're left with (difference).
When two identical signals of identical amplitude (volume) are combined and one is 180 degrees out of phase from the other you have complete cancellation of that audio. However, if one of those signals is a different amplitude, you don't get complete cancellation. And it's this principal that makes a balanced audio path work.
The output from a balanced piece of gear will have the audio signal on XLR pin 2 (hot). That same signal will be present on pin 3 (cold) however that signal is at a lower amplitude than the signal on pin 2. The shield/ground will be on pin 1. 

When the signal reaches a balanced input, the signal on pins 2 and 3 are combined with either pin 2 or pin 3 (usually pin 3) out of phase. If that cable happens to pick up interference along the way, it will be on all pins, in phase together and at the same amplitude. When it gets to the input, pins 2 and 3 are combined out of phase and any signal exhibiting the same amplitude (the noise) will cancel out completely. Since the audio is at different amplitudes, it doesn't cancel out and you're left with the difference: clean audio!

Heil, Shure and Sennheiser are manufacturers of premium microphones. They generally come with XLR plugs but Heil in particular provides a vast array of adapters to interface their mics to almost any make of transceiver. Bob Heil [K9EID] is a ham himself and has devoted a great deal of time to perfecting mics that sound good despite the poor conditions often encountered with HF Amateur Radio.

All amateur radio transmitters (except the new Yaesu FTdx9000) unfortunately use an unbalanced microphone input. It's sad, but true. In connecting a balanced microphone, equalizer, or audio device that uses balanced signals, care has to be taken in how the balanced signal is UNBALANCED in order to feed that unbalanced input.

So you can't generally just plug a mic with an XLR cable into a radio jack, even with a properly wired adapter. That's because the mic will almost certainly have a lower impedance than the input of what you're plugging it into, and that means that unless you correct things with a matching device, it will sound like junk. 

One option for HF home use is to invest about $45 in a small mixer such as a Behringer Xenyx 802. This unit comes with 1/4” and XLR jacks but will adapt to almost any mic.  It will even provide ‘phantom’ power to condenser mics when the radio does not provide it. The output of the mixer goes to your radio and you have full control over what your mic sounds like, particularly of you want to adjust the equalizer to punch through HF interference. I purchased mine at a music store here in Surrey and the difference is noticeable.



VHF and UHF Transceivers generally come with low cost and sometimes low quality microphones. The mic on your handy talkie or a typical handheld mic is a condenser microphone. Manufacturers use different plugs and pin configurations  though most amateur supply houses stock adaptors. 

If you are participating in an event where you may be on the radio as Net Control for an extended period, a headset and boom or desk mic and a foot pedal are a must. Not only does it leave your hands free but the audio quality and lessened background noise will provide much better communication. My Heil desk mic and Heil headset will interface with all my transceivers (and even my computer) with adapters.

Hints on using your mic effectively

If using a handi talkie, invest in a hand-held microphone. It will he healthier not having that antenna radiating right beside your brain and also more comfortable in use.
Talk across the front of the handheld mic rather than directly into it. This will provide a less harsh and therefore clearer sound.

Push the ‘Talk’ button and pause a second. This will permit the repeater and any interface equipment with an opportunity to fully power up and avoids a portion of your transmission being cut off.

In closing, be careful about switching mics from one transceiver to another. Not only are different makes using mics with different pin connections but some manufacturers use different mics with the same plug on different models within their own brand. Transceivers generally carry a small voltage on one of the mic pins to power the condenser element. If this voltage is shorted because a pin is connected to another point inside the mic, say to ground, damage to the transceiver may result.

There is an excellent site with pin-outs for different mics at https://www.scribd.com/doc/54320681/Microphone-Pinouts




Tuesday, September 11, 2018

RFI: A Practical Example Of The Effect


A Communicator Reprise: January 2013


At the suggestion of Jim Smith VE7FO, I recently joined an RFI reflector at http://lists.contesting.com/.  Why?  Because I hoped to find some answers to a frustrating Radio Frequency Interference (RFI) problem that I was experiencing.  

I had installed in my bathroom an electrically heated floor and thermostat c/w built-in ground fault interrupter (GFI).  However, whenever I transmitted, even briefly, on 15m or 10m the GFI would trip and the power would go off.  The first time this happened, the thermostat failed to work again even after resetting the GFI.  First call was to the supplier (NuHeat) of the “Solo” thermostat.  

Their customer support team knew nothing about RFI and I had to explain that it was likely a problem with the thermostat and not a problem with my radio transmissions.  Without argument, they replaced the thermostat with a new one (#2).  Not wanting to take further chances with ruining another thermostat, I decided to install some RF protective devices, as I assumed that the 220 v house wiring was picking up RF and passing it through to the thermostat. 

While RF interference is not a new problem, it is most commonly experienced with telephones and audio devices.  However, nowadays the large variety of RF susceptible electronic devices in our houses has greatly increased the likelihood of problems.  The number of devices emitting RF has also increased accordingly.  Plasma TVs, computer monitors, electric fences, touch turn-on lamps, halogen lights, and wall-wart switching power supplies are just some of the items that are reputed to send out wide-spectrum RF, but there are many others.  What to do in this case? 

First, I applied the standard remedy: I clamped split ferrite cores around the power cable near the thermostat.  That appeared to have no effect, however this time the thermostat could be reset and made functional, which was progress of a sort.  Then I ordered an RFI kit from Palomar and when it arrived I added ferrite beads to the individual power leads.  No improvement.  Next I connected .01 uF disc ceramic capacitors between the hot leads and ground.  Also NuHeat had provided me with a “snubber” – a capacitor with a resistor in series – which I connected across the power leads.   However, the problem persisted.  Finally after many emails and telephone back and forth, NuHeat put me in touch with Honeywell, the manufacturer of the thermostat.  

Honeywell responded very quickly first asking me some questions about my power level, frequencies, SWR etc that might suggest a transmitter problem.  After they were satisfied with the answers, Honeywell couriered another thermostat (#3) to me for trial.  No cigar.  When I reported this failure, they promptly sent me yet another thermostat (#4) called “Harmony”.  This is a more expensive device of (apparently) different design.  It worked!  

One by one, I removed the RF chokes and capacitors until they were all gone.  After several days of testing at different frequencies, there has been no effect on the thermostat/GFI, so I mounted it permanently and thanked Honeywell for their efficient service. 

Lesson: if you have an RFI issue, try the standard remedies but when they fail to solve the problem, get the manufacturer on board with device replacement in mind, as with modern radios it is typically not the radio transmissions that are at fault.  This approach may not work with some of the off-shore manufacturers, so bear this in mind when purchasing electronic devices – they may not care about their reputation and customer service the way Honeywell does. 

ARRL publishes several good RFI guides as well as the Radio Amateurs Handbook and more information can be found on the Internet.  For unusual problems that defy the conventional solutions, the RFI reflector website mentioned above is another excellent source of expert advice.

~ John VA7XB
   Now enjoying toasty toes in his remodeled bathroom.




Friday, September 7, 2018

SARC Contest Contender: September-October 2018




The Fall Contest Season


John VA7XB has taken on the job of Contest Manager and is proposing an active schedule for the next year now that SARC has two contest grade radios available for club use at the OTC.

For that purpose John would like to know who would like to be notified about upcoming contests.  If you have an interest in contesting, please contact John at va7xb@rac.ca with your preferred mode(s) and he will put you on the contact list. The objective for this fiscal year will be for SARC to compete in at least one contest a month so that members may acquire comfort with operating our new radios, accurately recording exchange information and using logging software. 

If your main interest is in emergency communication, these contests provide invaluable experience in operating under sometimes chaotic conditions including multi-station pileups, QRM (man-made interference), QRN (natural interference), lids (bad operators), over-the-pole flutter, static crashes and fading. 
If there is sufficient interest, we may even try some of the more exotic digital modes.
We cannot do them all, of course, but listed here are a few of the available contests for the months of September and October.

These and other contests are described at: http://www.contestcalendar.com//index.html



Monday, September 3, 2018

Surrey Basic Amateur Radio Course




Register Now... We Start Tuesday, September 11


The Surrey Amateur Radio Club generally offers two Basic licensing courses per year. Last year we graduated 27 members who attended our classes. These new 'Hams' came from all walks of life, some with technical backgrounds, most without. Many were interested in emergency preparedness and staying in touch if the BIG one hits.

We have set the start for the next class as Tuesday, September 11th at 6:30pm. We use the excellent classroom facilities courtesy of the Surrey Fire Service at their training facility 14901 64th Avenue, Surrey, BC.

Have a look at what Amateur Radio can offer:

An exciting modern hobby



A useful emergency communications skill





Have a look at our Basic Course brochure and poster



Saturday, September 1, 2018

The September 2018 Communicator


We're Back! Here is the latest Communicator 

After our Summer recess we have over 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 
goo.gl/8Kekuo



http://goo.gl/8Kekuo

As always, thank you to our contributors, and your feedback is always welcome.  My deadline for the October edition is September 14th. 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

Keep visiting this site for regular updates and news.

~ 73,
  John VE7TI
  Communicator Editor

Wednesday, August 15, 2018

My Screwdriver Antenna Experiences



Even On A Compact SUV


Some of you may be familiar with the Hi-Q line of mobile HF antennas. SEPAR has several, a choice prompted by the need for a relatively compact, portable HF antenna that is quick to set-up in the field, at least until a more robust antenna can he erected. As an RV’er I decided that I needed a usable mobile HF antenna that I could erect quickly, but that would provide me with a worthwhile HF experience. There is nothing worse than spending hours at the radio and not hearing a soul on the air!

In order, my criteria were:

  • Performance 
  • Size;
  • Ease of set-up (not necessarily speed);
  • Ruggedness; and
  • Solid mount

I researched a number of mobile HF antennas including the Buddipole and Tarheel products. Not to bad-mouth these other products, but I tried both and was not satisfied that they would meet my expectations. I was impressed by the quality of construction and military spec components of the Hi-Q. Performance reports were good (provided it is properly installed) and it met my needs for ease of transport and mounting.

Hi-Q antennas are made in the workshop of Charlie Gyenes, W6HIQ, VA7HIQ in Wildomar, CA about 150 Km SE of Los Angeles. Charlie has been supplying these antennas for over 20 years and is a supplier to the US military and NASA. I visited Charlie to pick up my Hi-Q  and he is an interesting, though opinionated fellow who came to the US from Hungary via Canada during the 1956 revolution. Charlie worked for Boeing before setting out on his own.

Charlies’s workshop is modest, consisting of a medium sized building beside his home. When I visited, he had about 20 Hi-Q’s ready to go. He also showed me several military antennas—ruggedized versions of the Hi-Q, and a huge VLF antenna which was to be installed aboard a US Navy submarine. His test equipment is impressive and his greatest joy is in developing new concepts which can be incorporated into his antenna designs. I mentioned Charlie was opinionated… he pulls no punches when describing his competition and he is obviously very proud of his product. 

Before we left, Charlie’s wife, a lovely lady, insisted on preparing lunch before we headed out with the antenna. 

Some Mis-steps

Arriving at our Palm Springs RV Resort, I set up the antenna on a satellite stand, a setup we had used with SEPAR at community displays. This antenna is a typical screwdriver design, the coil being contained in a 20cm diameter plastic housing. A rotor moves up or down the inside of the coil to decrease or increase the virtual length of the antenna, thereby tuning it to the appropriate frequency. To complete that process, the user can use something as simple as a toggle switch, a turns counter, or a third party automatic antenna tuner. I had opted to purchase Charlie’s turns counter, basically a switch box with an LED numeric display that shows how many turns are in the antenna circuit. This worked but I found it less precise and it was easy to under or overshoot the target frequency with just one rotation. 

Palm Springs is in a ‘bowl’, surrounded by tall mountains, I found that the antenna performed well for strong stations within 1000 Km, but was not stellar for DX.

The ‘Right’ Set-up

This year we sold the RV but I still wanted to be able to travel with the Hi-Q to operate mobile. We stay in an RV Resort with antenna restrictions, but they do not cover antennas on vehicles. We often travel with bicycles and my wife suggested I find a way to mount it on the car’s bike carrier (see photo below). This also permitted me to easily remove either just the antenna or the rack and antenna. I added a ground strap to the frame and also added a current balun to the feedline. Additionally, I extend about 20ft of plain hookup wire directly out from the rear of the vehicle... kind of a counterpoise. With this revised setup and my Icom 7000 (100 Watts max.) I worked the CQ WW DX contest. What a difference! Granted the conditions were excellent and even the high bands were open but the results were immediate and surpassed any previous use of the Hi-Q. I worked stations throughout the US, Canada and the Caribbean. I also worked Portugal, Mexico, Japan and added two new countries, Curacao and Cape Verde—the latter my first African contact. On all bands I got an SWR less than 1.6 and as low as 1.1 on 20m.

I’ve  now purchased the automatic tuner for use with my Icom, a purchase that I hope will ease tuning and further improve my portable station. Given my recent experience, I’d recommend this set-up for anyone with strata restrictions wishing to operate HF.

More info at: http://www.hiqantennas.com/

The Hi-Q with whip is 12' high
The bicycle mount provides enough height to
work HF, even on the low bands







CQ CQ CQ

Reflecting On The Summer Forest Fires

Over 500 Forest Fires The Largest, Longest, Most Expensive Fire Season Ever In the Greater Vancouver area, we have not had to endure...

The Most Viewed...