Radio Habana Cuba: Dxers Unlimited edition for February 13, 2001
By Arnie Coro, radio amateur CO2KK
Hi amigos, welcome to the mid-week edition of Dxers Unlimited, coming to you from Havana. I am Arnie Coro, radio amateur CO2KK, and here are today's headlines: Radio noise is the worst enemy of the radio enthusiast... radio frequency energy that interferes with the reception of wanted signals can come from many different sources, which sometimes are really very difficult to find and then eliminate them... That's why reception of radio signals is becoming so difficult in our cities, and even those that happen to live way out in the countryside, have to deal with noise-generating devices that have become part of our daily life. Not even those that generate their own green electricity from solar panels or small hydroelectric units are exempt from radio noise!!! That's why today I'll dedicate most of Dxers Unlimited's airtime to talk about radio noise and, thanks to the kind contribution of my good friend and long time faithful listener of this show, Bruce Atchinson from Canada, I'll share with you an article he wrote about the new light-emitting diode lamps intended to replace regular lightbulbs, both incandescent and compact fluorescent.
As always, at the end of the show, you will be able to pick up the latest HF plus 6 meters propagation update and forecast. Now stay right on this same frequency, I'll be back in a few seconds. Margarita Delgado is my sound engineer and producer, I am Arnie Coro in Havana....
You are listening to the mid-week edition of Dxers Unlimited, and for your information our e-mail address is arnie@radiohc.org, to which you can send your signal reports and comments about the show, as well as your radio hobby related questions for Dxers Unlimited's popular section, "You have questions and Arnie answers them." Via AIR MAIL, a postcard will do, send it to Arnie Coro, Radio Havana Cuba, Havana, Cuba.
Now, as promised, here is the article about the new ZERO RADIO NOISE Light Emitting Diode lamps, written by VE6XTC, Bruce Atchinson. Here is how he started his e-mail to me, and I quote: Dear Arnie, I wrote this article for a local newspaper. I believe this is a solution to those complact fluorescent bulbs which make so much noise. Here is what I wrote... and Bruce's article starts here:
Now that we are officially in the 21st century, isn't it high time for a new kind of lighting system? The incandescent bulb has been around since Thomas Edison invented it in 1879. Though fluorescent lamps consume about 70% less power than incandescent lights, they also rely upon heating filaments to make them glow. AND both fluorescent and especially the new electronic compact fluorescent lamps are very powerful radio noise generators that produce a lot of interference to radio reception.Thank you very much, Bruce Atchinson from Alberta, Canada for this nice article, and after you sent it to me, I connected an array of 8 red light emitting diodes of the type used as panel lamps, fed them from a battery and YES, the LED lamp works very well indeed and it needs much less current from the battery than a standard flashlight bulb. Of course, the light produced does not have the ideal spectral energy distribution needed for reading, etc., but it does work very well as an emergency long-lasting lamp, which is practically break proof!! No more flashlight bulb filaments to worry about! LED lamps with appropriate spectral energy light distribution should be excellent replacements for the very noisy energy saver fluorescent lamps that are now becoming one of the radio listener's worst nightmares!A new energy-efficient light source will soon be available which uses silicon, the same material that transistors and integrated circuits are made from.
Since the late seventies, we have had light-emitting diodes, abbreviated LEDs, as indicators on equipment and as digital read-outs on clocks and calculators. Now, a white color LED has been developed, and it is bright enough to be used as a light source. Nowdays several suppliers are marketing replacements for various types of incandescent bulbs that use LED's. Though the light isn't exactly a pure white colour, improvements are constantly being made to the semiconductor materials. The LED arrays only use a fraction of the wattage that conventional lamps use and yet they provide the same amount of illumination. They are also extremely rugged from a mechanical point of view -- no filaments to open up, no glass to break.
One example of this is their LED 60 Watt bulb replacement. According to a catalog available from one of the suppliers, the LED array consumes only 5 watts of power but produces the same light level as a 60 watt lamp. And, as expected, it generates a lot less heat than the incandescent lamp or even a compact fluorescent electronic lamp. This discrepancy in power consumption is due to the fact that the tungsten filament in the standard incandescent lamp produces 90% of its output as heat. LEDs convert electricity directly into light.
Light emitting diodes direct flashlight bulb replacements are now also available. These are highly useful in various situations, such as camping or cave exploring, where incandescent lamps give the batteries a real workout. Other types of LED arrays are also available, including flood lamps and car taillights and headlights.
Exciting developments and new applications of LEDs will soon be common in everyday life. Some cities are currently looking into replacing incandescent traffic lights with LEDs. A variety of manufacturers now make LEDs which emit ultraviolet light. These are ideal for mineralogists needing a portable UV light source. Laser LEDs already are being used in cartography, architecture, lecture halls and other applications. Anywhere a light is needed, these versatile semiconductor devices will soon be found.
One nice thing about these LED arrays is that they can last up to 100,000 hours before needing to be replaced, and that's ten times longer life than even the best-quality compact electronic fluorescent energy-saving lightbulbs!!! With the alarming rise of the cost of electric power worldwide, it makes perfect sense to buy these penny-pinching long-lasting LED lamps. Though they seem expensive -- a 60-watt bulb replacement costing now about $50 US dollars each -- these energy-efficient lights save money in the long run, and prices are expected to go down soon, too.
The new LED lamps also can decrease green house gas emissions by lessening the energy demands from homes and businesses. AND, OF COURSE -- what is most important for us radio hobbyists -- LED lamps do not generate any kind of radio frequency noise whatsoever!!! As a matter of fact, it would be an excellent idea, as soon as they are cheaper, to replace all the lamps near your radios with the new Light Emitting Diode ones!
You are listening to Radio Havana Cuba, and this is a special edition of Dxers Unlimited devoted to RADIO NOISE SUPPRESION... LED lamps now becoming available are one nice way to go in the future, as soon as they become cheaper, but right now you can reduce your radio noise by changing your fluorescent lamps periodically, as soon as they show blackening at the tube ends. when standard fluorescent lamps show black stripes at their ends, it is time to replace them, because that's when they generate a lot of radio frequency noise. Another RADIO NOISE SUPPRESION TIP: Install AC power line filters on the lines that supply the room where you have your radios. The filters must be installed at the electricity input box, and right next to the radios... YES, you will need two filters, not just one, and a good low-resistance ground connection for the AC power line noise filters. When properly built and installed, the AC power line noise filters will reduce the RF noise reaching your radio via the AC supply significantly... and one added bonus, in case you are an active radio amateur, is that the filter will block any RF generated by your transmitter or transceiver from entering the household wiring and producing interference with your TV set, VCR or stereo!
Another good idea for reducing radio noise is to run a complete check of your home's electrical system, done by a professional electrician, of course. It is amazing to see how many home electrical systems have gone without any kind of maintenance whatsoever for years and years, and how preventive maintenance can help not only reduce radio noise, but also even prevent dangerous problems from happening. Not too long ago, while trying to find the source of terrible radio noise at a friend's home, we found a very loose terminal at a circuit breaker that was arcing almost constantly -- a likely candidate to generate an electrical fire in the not too-distant-future, if we had not caught it in time! Amigos, my friends, mes amis, fighting against radio noise sources is not an easy job. But you will certainly learn a lot about radio by attempting to reduce your present noise levels. YES... that tick-tick-tick that was spoiling your AM DX session was from an aquarium pump, while the constant BUZZ came from a light dimmer that may be replaced by a very conventional on-off switch, and the soft buzz that you have heard all across the 60 meter Tropical Band could be completely wiped out, just by replacing four or five of the fluorescent lamps that are the most used ones in your home environment.
In another edition of Dxers Unlimited, I'll bring you PART TWO of radio frequency noise finding and removal!
Now as always at the end of the show, here is Arnie Coro's Dxers Unlimited's HF plus 6 meters propagation update and forecast... The present solar rotation should show minimum activity this week, and then we will see very probably a rather slow upward trend of the daily solar flux. Tuesday morning the number of sunspots was down to about 105, still good enough to keep the MAXIMUM USEABLE FREQUENCIES way above 25 megaHertz during most of the local daylight hours. And do remember that the Frequency of Optimum Traffic is roughly about 80 percent of the MUF, so that explains why reception from about 18 to 30 megaHertz is so good during local daylight hours nowadays. The average 90-day figure for the solar flux is still above 170 units!
For short wave listeners, best nighttime easy listening will be on the 25 and 22 meter bands, with 31 meters as a second option. Short path radio circuits, involving distances of 1000 to 2000 kilometers, will continue to work well on the 5 to 7 megaHertz range. For amateur radio operators here is my advice: Look for DX on 10 meters during daytime, and move to 20 meters at night... without forgetting about 40 and 80 meters!
See you at the weekend edition of Dxers Unlimited, and as always I am very grateful for your comments and ideas about the show... send them to arnie@radiohc.org and do remember to include a signal report, too!
Arnie Coro CO2KK
Havana, Cuba
February 13, 2001Postal address:
Arnie Coro, "Dxers Unlimited"
Radio Havana Cuba, Havana, CUBA
e-mail: arnie@radiohc.org
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