DOUGLAS COUNTY AMATEUR RADIO CLUB NEWSLETTER
Volume 31, Number 3, March, 2001
Articles and information for the Newsletter may be submitted up to the 25th of the month before the next meeting.
Ken Blair, KC0GL, Editor
1711 West 19th Terrace
Lawrence, KS 66046
Phone: 843-8826
e-mail: kc0gl@arrl.net
This Newsletter is published monthly by the Douglas County Amateur Radio Club (DCARC). Reprint permission is granted to other Amateur Radio-oriented publications (expept for copyrighted material as noted) provided that credit is given to the author and source. Opinions expressed herein are not necessarily those of the club or its officers.
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During the remodeling at the EOC, the east entrance will no longer be available to us. Enter the west entrance and take the elevator to the lower level where our Club usually meets.
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KPH was a well-known marine telegraphy station, based up the coast from San Francisco at Point Reyes. K6KPH now is on the air re-activating that station on our ham bands. We'll have pictures of the old marine station and discuss the ham station operation in this unusual location where the San Andreas fault meets the Pacific Ocean, which I visited 20 years ago.
Jim Canaday, N6YR, Program Chair
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March 10-an important date-is just a few days away. Put it on your calendar and plan to hop over to KC and attend the HAMBASH 2001 sponsored by the Ararat Amateur Radio Shrine Club, 5100 Ararat Drive, Kansas City, MO.
Hamfests of this size, or in fact any size, are becomming rare so it is important that the attendance warrants putting it on next year. In the past the Hambash has had a very large area for amateur tables and another area for commercial exhibits. You can always find something that you didn't even know you were looking for.
One advertised highlight is a program presented by Bob Heil whose company manufactures top-line microphones. If you have never heard Bob present a program he is very entertaining as well as informative. You may not agree with all Bob says but he is as emotional about his microphones as any TV evangelist. Don't miss the Hambash and especially Bob's program on microphones.
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Bob Rainbolt, WB0AUQ
This month's picks for the neat, interesting, and/or just plain quirky:
Check out this recent scientific breakthrough, if this stuff works for the audiophiles it should work in RF applications:
http://www.audioasylum.com/audio/general/messages/104180.html
Speaking of audiophiles (or is that audiophooles?), here's a nice little audio amplifier:
http://www.alumrocktech.com/
Everything you always wanted to know about batteries:
http://data.energizer.com/batteryinfo/
An audio oscilloscope for your PC and soundcard:
http://polly.phys.msu.su/~zeld/oscill.html
More soundcard stuff, including a neat tone generator:
http://www.nch.com.au/action/index.html
This one from Vince/KC0DLP, maybe his challenge to just build something?:
http://www.vintagehamradio.com/junkbox-xmtr2/
Need some quick info on JP-5 fuel, a refresher on anchoring a ship,
or perhaps amateur operations near military radar sites? This one has it all:
http://braddock.com/library/
Have fun surfin'. 73, Bob/WBOAUQ
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Abbott, Jeff, P.O. Box 3364, Lawrence KS 66047
Armstrong, Chris, 1052 Hartland Dr, Lawrence KS 66049
Armstrong, John, 1052 Hartland Dr, Lawrence KS 66049
Higgins, Shirley, 422 Elm, Lawrence KS 66044
*Learned, George, 1065 Wellington, Lawrence KS 66049
Miller, Aaron, 1420 Apple Lane, Lawrence KS 66049
Schweppe, Justin, 2205 Breckenridge Dr Lawrence KS 66047
Seiwald, Cheryl, 2777 US 59 Hwy, Perry KS 66073
Shorock, Thomas, 1607 W. 9th #3A, Lawrence KS 66044
Workman, Kevin, 3016 W. 24th Terr, Lawrence KS 66047
Young, Ledell, 1301 W. 24th #I-21, Lawrence KS 66046
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*Club member, WDOFAI, taking course to upgrade.
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SHORTWAVE-The 2001 Technician Class is off to a good start. We have 11 students enrolled and all seem excited to have the opportunity to get started in amateur radio. We have a couple of boy scouts, some college students, and several working adults in the class this year. Jim, Earl, and I appreciate the assistance of several club members who have assisted us at the first 2 class sessions. If you haven't done so yet, please feel free to come to one of the Monday night classes and meet the prospective new members of the ham community....73, Bob Drake, N0TFU
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SHORTWAVE-I received the message below from a qrp email reflector
tonight and thought that others here might want to check it out also.
The entire manual is online at http://www.raes.ab.ca/book/main.htm
with suggestions for copying, sending, and historical background info
on different alphabets. Definitely worth a look!
-73, Vince Francisco, KC0DLP.
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I have found William G. Pierpont's (N0HFF) book "The Art and Skill of Radio-Telegraphy" to be excellent for learning and increasing your code speed. It is informative whether you are a beginner that presently knows no code or an experienced 30WPM operator. An on-line version can be found at the following URL: http://www.raes.ab.ca/book/main.htm
-73, Steve Yates - AA5TB Fort Worth, TX - EM12gs aa5tb@arrl.net http://www.geocities.com/aa5tb
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Rex Lockwood, W0FOG, Secretary
Twelve attendees signed in.
Bob Drake, N0TFU, showed an edited video that was used in the radio classes. He discussed the upcoming classes and options of teaching. Online test sites for interested members were mentioned: Hamtest.com QRZ.com and ARRL.com.
The next program will be about the Maritime Service Coastal Station.
Vince, KC0DLP, looked into getting space at the fairgrounds for a tailgate or hamfest. Fees were $20 half day to $40 all day. Possible parking lot space would be free. Vince is still checking to get final prices and options. He is also looking into signing up for Wells Overlook for Field Day since the park's future is a little shaky right now.
The Club auction was mentioned as coming up in April and the Douglas County "Arc and Spoke Ride" is coming on May 5th.
Treasurer's Report: Started the meeting with $349.90 in the repeater fund and $700.59 in the general fund. Paid out $62.26 for newsletters and postage.
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FOR SALE-Equipment and asking prices: Yaesu dual band handheld, $250 / Kenwood TS 690S with antenna tuner, $650 / Cushcraft vertical antenna, $250 / Kenwood TM-731 dualband handhels (with mods), $275 / 2m/70cm Diamond dualband base antenna, $70. Either Pam or Rick Johnson NOMED, can be reached in the evenings at 842-7649. (Submitted by Ruth Hull, N0LUD.)
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Recently I purchased a used tower that had to be disassembled. Normally this would be of no real concern, just organize a crew to help take it down and pick a convenient day-a day that is nice and pleasant to be outside working and climbing on a tower. I contacted some fellow hams for help and started to set a date. Well, lo and behold, Murphy's law took effect. Strike one: I found that it needed to be taken down as soon as possible. Strike two: The weather was taking a turn for the worse and it might be a week or two before nice weather returned. Strike three: I had to take it down by myself.
So I took the afternoon off from work to accomplish the task at hand. By the time I got to the tower site it was raining real hard. I sat for awhile and waited for the rain to ease up. With my safety belt on, I climbed the tower and took the antenna down and took the bolts out of the top section. The remaining problem was how to disassemble a standing 60 foot tower. It was starting to rain again so I came down and took the antenna home.
After burning the brain cells for a little while, I crossed my fingers and gave Ken Olson, AF3RM, a call. What luck, he was home and I was able to borrow his gin pole that is designed for assembling and disassembling Rohn towers. The gin pole, along with some rope, solved that part of the puzzle. Now if anyone has ever disassembled a tower, in the air or on the ground, it is very difficult to get the sections apart by yourself. (Ken can again verify this as I bought a small tower at an auction last summer and he helped me disassemble it on the ground). With this in mind I knew I had a huge task ahead.
Thanks to "necessity being the mother of invention," I came up with an idea that worked fantastically. Take note all. I cut two pieces of 3/4 inch plywood that fit inside the tower legs and placed them on the rungs. Next I got a scissors jack from one of my old cars. I drilled holes in a corner of both boards and tied the jack and boards together. With the needed tools, I was off to the tower site again. Call me crazy, but with thunder, lightning and rain, I started to tackle the task at hand.
Time 1:30 p.m. Having climbed the tower, I pulled up the gin pole and attached it in place. I tied the rope to the top section, pulled it tight and tied the other end to the next section down. I then inserted the plywood with the jack between two tower sections and started cranking the jack up. At times the tower would bind a little but shoving on one side or the other usually freed it up quickly. If not I just lowered the jack a little and slid it from the center of the tower to the leg that was binding and up it went. Once it was free all I had to do was grab the rope, untie it and lower away. Lowering the section down from the height was a task unto itself but thanks to the gin pole it was possible. I repeated this procedure until all sections and myself were safely on the ground and loaded up in the truck. Time: 4:30 p.m. Three hours to take a 70 foot tower down.
I was soaked to the skin from the rain and when the wind began to pick up, I knew I was definitely crazy and/or insane to have undertaken this project in such weather conditions. I don't recommend doing a project like this in inclement weather nor would I do it again.
I guess what thrilled me about it all was the fact that my idea worked great and I was able to do the job myself. I really would have enjoyed some help but as I said time became a crucial factor. My many thanks to those that offered to help and especially to Ken, for without the gin pole I couldn't have done it so easily. See you all when it's time for the towers to go back up!-73, Rex Lockwood WOFOG
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AmateurRadio history was made this month when amateurs in Canada and the UK completed what appears to be the first two-way transatlantic Amateur Radio exchange on 136 kHz. Larry Kayser, VA3LK, and Lawrence "Laurie" Mayhead, G3AQC, managed the LF feat using extremely slow CW that featured 90-second-long dits and 180-second-long dahs. The two-way contact took two weeks to complete.
"We are the first to do a two-way QSO on LF across the North Atlantic as far as I am concerned," Kayser said. "We are the ones who put the stakes in the ground; others will build on what we have done."
The VA3LK-G3AQC contact began February 5 and was completed February 19 with the reception and confirmation of VA3LK's report by G3AQC. Both stations used spectrographic software and computers for receiving. The participants agreed in advance to a "firewall" between them for the duration of the contact and that all QSO information was exchanged over the LF radio link.
The UK has an amateur band at 136 kHz. While Canada has not yet authorized general Amateur Radio operation on 136 kHz, Kayser and a few other Canadian amateurs have received special authorization to conduct LF experiments there.
G3AQC and VA3LK were using a combination of commercial and surplus equipment at their respective stations. G3AQC estimated his effective radiated power at 350 mW, while VA3LK said he might have been at the 5 W ERP level.
In October 1998, the ARRL petitioned the FCC to create two amateur LF allocations at 135.7-137.8 kHz and 160- 190 kHz. The FCC has not yet acted on the request.
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This 1997 EARC Wireless Dispatch article was recently updated, including some technical feedback provided by Chris Mullis, KH7CL and Mike Burger, AH7R.
This article contains highlights of an EARC general meeting program presented on April 24, 1997.
Amateur radio is a pastime that is based on science. It is also based on art.
Hard science such as physics, meteorology and chemistry gives us the certainty to explain and comprehend much of how amateur radio works. The "art" comes from seeing things in a new light, blending essential building blocks with intuition and creativity to make new "big picture" applications of amateur radio.
It is when we master and shape each chosen aspect of amateur radio that we go beyond simple nuts-and-bolts technicians to become true artisans and "radio magicians." Any handbook or textbook will explain the nuts and bolts that we gladly explain, but have you spent a moment to think "outside the box" and grasp a bigger picture?
For example, in a phrase or sentence, how do we generate radio waves? No, the answer isn't "Put the batteries into the walkie, press on the PTT switch and talk!" To oversimplify, a radio wave is an oscillating variation of a magnetic field. The key points are oscillation, variation and magnetic.
Suppose we had a magnet and could rotate it rapidly. It would cause a variation in the surrounding magnetic field that would be cyclical. That variation would emanate and spread from that magnet. If somehow we could rotate it fast enough, the variation would appear in the usual radio frequencies. We would need to do that thousands or millions of times a second.
Rather than physically spin the magnet, what we would really like to do is to pulse the intensity of the magnet. It's not practical to physically intensify or diminish a magnet that fast, but we can use the relationship between electricity and magnetism to pulse a magnet electrically. To see this, let's use an everyday illustration.
Suppose you were at the edge of a pond and had a wooden ball floating on the water attached to a string. What happens as you pull the string up and down in a repetitive fashion? The ball would bounce up and down, and induce waves that move across the surface of the water.
What happens when the wave hits another wooden ball nearby? The ball bounces up and down. If we could detect and harness the movement of that second ball, we would have a smaller version of the original motion. The horizontal wave action has been reconverted into vertical motion.
Now, to see the what happens when we transmit through an antenna, view the string as being electricity, the wooden ball as an electron and the disturbed surface of the water as an emanating electromagnetic wave. Like the string, if we attached an RF (radio frequency) generator to a vertical dipole antenna, the moving vertical electric voltage is like the string upon the electric current. It moves electrons (the wooden ball) to create an electromagnetic field that spreads out horizontally from the antenna wire.
As the current grows, the field intensifies, expands and spreads out. The essentially magnetic field cuts across neighboring electrical conductors or wires, and like the wave upon the second wooden ball, induces the electrons to move and form a minute current in the neighboring wire. And it turns out that the effect works regardless of whether the antenna wire is positioned vertically or horizontally.
The magnetic field can penetrate through many objects as well as be reflected or absorbed by other objects. The importance of this will be discussed in the next article. There is also an electric field that emanates, and it interacts with the magnetic field, exchanging power and restoring equal magnitude to the electric and magnetic fields.
Our jobs as hams is to convert electric current in a vertical piece of wire into horizontal magnetic waves, propagate the waves, and detect it by converting it into vertical electrical current in a second piece of wire. When we amplify that detected current, we have a signal. That is the essence of what we do.
The magnetic wave never really disappears. It may be faint, but it is still present. When the transmitter on the Pioneer spacecraft was shut off last month, it was far beyond the edge of the solar system. The received signal strength was one trillionth of one billionth of a watt and took an array of antennae and receivers to detect it, but it was still present and detectable well below the surrounding noise level.
Incidentally, the above shows that an electron is like a magnet. Since electrons move about in an orbit around the atom nucleus, they exhibit a current which produces magnetism. By using current flow to move the electron, we've electrically moved and pulsed a miniature magnet.Summer Programs
With permission from the EARC Wireless Dispatch, O'ahu, Hawaii ARC
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HERETOFORE it has been customary for all but the most ardent fans to put away their radio receivers early in June to give heed to the call of the wild. As a wintertime source of entertainment radio came into its own early in the development of broadcasting, but during the warmer months it has been laid aside for outdoor sports and other diversions or, at least, given only secondary consideration as a recreation.
Nature has been partly to blame for this. Static and other atmospheric disturbances have seriously interfered with good hot-weather reception, and for this reason many broadcasting stations curtailed or discontinued their summer schedules, so that the public at large has come to believe that the radio set might just as well be forgotten during the summer.
Static is yet to be conquered for the great majority of listeners. Antistatic devices have been developed in laboratories but they are not yet available in commercial form. In spite of this fact, however, it seems probable that this season will usher in a new era of summertime use of radio as a result of approximately fifty stations having increased their power during the past twelve months, and the use by others of superpower.
The increase in power varies from 500 watts to ten times that figure. The superpower stations will operate on 50,000 watts. The increased power is going to mean better and more continuously satisfactory reception over a greater range and with less interference from static than has ever before been possible. This, combined with the fact that more and better programs are planned than were offered any previous summer, makes certain that we are at the beginning of a greater use of radio during the warmer months of the year.
The stations which have increased their power are scattered from the Atlantic to the Pacific coasts and from New Mexico to, and including, many Canadian broadcasters, so that radio fans throughout the entire United States and Canada will benefit by the increased power.
Early in the spring the Radio Editor wrote to all of the major broadcasting station managers asking for an outline of their contemplated activities during the coming summer. In every instance, except in the cases of schools and colleges which are closed from June to September, the replies stated that winter schedules would be continued through the summer with only such minor changes as would seem appropriate, such as the addition of sporting events and music of a lighter nature, including band programs.
Probably no one will profit more from the increase in broadcasting power than the farmers who depend upon radio for their weather, market and highway reports. The major stations which transmit this valuable information are, in practically every case, those which have added additional tubes to their sets or else installed new transmitters, so that farmers who, in past summers, have had difficulty tuning in on this much-needed information will now be assured of practically uninterrupted service. This is in no way to be construed as a guaranty (sic) that everyone will hear every desired station without summertime atmospheric interference, but the added power will go far toward insuring uninterrupted service from the nearest high-powered broadcasters.
Among the outstanding events of interest to owners of radio receivers which are scheduled for the summer are the Atwater Kent programs which, with some modification, will be continued each Sunday evening throughout the summer with the same chain of stations from which were radiated the winter concerts.
President Coolidge's address before the semiannual meeting of the Budget Bureau in Washington, to be held June twenty-first, will, according to present plans, be broadcast by all the major stations comprising the American Telephone and Telegraph chain of stations. Other events of outstanding national importance which will be heard from these same stations are those which will take place on the grounds of the Sesqui-Centennial Exposition at Philadelphia, which commemorates the one hundred and fiftieth anniversary of the signing of the Declaration of Independence.
The most important event of this kind scheduled when this issue went to press is the July Fourth address of the President. It is probable also that speeches delivered by other notables who attend the fair will be broadcast by this same chain of stations. Plans also have been made to broadcast other events through one of the large Philadelphia stations so that everyone within receiving range will be able to listen to something of interest from this source. The good-will programs, to which radio fans have come to look forward each week and which will be continued throughout the summer from the same chain of stations which broadcast the winter programs, are the City Service Quartette, Cliquot Club Esquimaux, Davis Saxophone Octette, Eagle Neutrodyne Trio, Eureka Vacuum Cleaner half hour of diversified music, Eveready Hour, Goodrich Silvertown Cord Orchestra and the Silver Masked Tenor, the Gold Dust Twins, Hires Harvesters, Ipana Troubadours, Shinola Merrymakers and the Whittall Anglo-Persian Orchestra. The Metropolitan Life Health Exercises at 6:45, 7:00, 7:15 and 7:30 A.M. will be broadcast through the summer from the same stations which transmitted these setting-up (sic) exercises during the winter.
Some of the large broadcasting stations had not completed their summer schedules when this article was written, but the following are examples of what you may expect your radio to bring to you this summer: Religious services; crop and market, livestock, fruit, vegetable, poultry, butter, eggs and shipping-point reports, hay and grain quotations, weather forecasts, market summaries, timely talks on agriculture, women's programs, road conditions and time signals. In addition, many summertime sporting events will be broadcast, chief of which will be baseball games, horse races, polo games, field and track meets and boat races. Radio is unquestionably destined to reach a stage of development where it will be as popular in summer as it has been in winter. There is no doubt about the increasing use of radio receivers during the warmer months of the year, and every change that tends to better transmission and reception will add countless numbers to those who have come to use their sets as much during the summer as in winter. Those who enjoy listening to broadcast programs will, from now on, realize more service and pleasure from their sets than ever before and those who postpone their purchases are only depriving themselves of the satisfaction, pleasure and inspiration which only a radio receiver could bring to them during the intervening months.
-Stuart C. Mahany
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The following questions have been submitted to the Radio Editor for reply. Because of their general interest the answers are given herewith for the benefit of others who may be interested in seeing them.
Q. I have been using two 45-volt dry cell B batteries which have depreciated through service to a little under 40 volts each. Can I prolong the service of these batteries by connecting an ordinary 6-volt dry battery to each, thus increasing their energy to the normal 45 volts of each unit? How should the additional dry cells be connected?
A. Your suggestion does not work out in practice for the reason that when a fresh dry cell is connected to one which is partially exhausted, the older one reduces the energy of the fresh one to the lowest level of the partially used battery. This takes place a very short time after the combination is put into service and practically no benefit is derived from the new battery. You will find it much more satisfactory to replace your dry-cell batteries with new ones as soon as they have depreciated to the point where they will no longer operate your receiver.
Q. What is the explanation for the mirror-like coating on the inside of vacuum tubes?
A. Tubes of the type which have thoriated filaments require a very high vacuum to function at their greatest efficiency, therefore some method must be employed to remove all traces of moisture and carbon monoxide and other gases present when the tubes are made. To do this, an element which readily combines with these gases is introduced within the glass bulb and during the process of exhaustion it volatilizes and combines with the unwanted gases. The element introduced for this purpose then deposits itself on the inside of the bulb, resulting in the mirror-like appearance of the finished tube. Magnesium metal is often employed and the silver coating is the result of its use.
Q. I am interested in radio and would like to build a set. Is there much possibility of its becoming out of date as a result of any new radio inventions?
A. If a standard circuit is followed in constructing your set it should be useful for a long time to come. The laws governing radio transmission and reception are practically unchanged from the early days of its development, and a receiver built along standard lines is not likely to become obsolete due to any new inventions that could not be incorporated in your set.
Q. In tuning my homemade radio set I have difficulty in keeping the station tuned in when I remove my hand from the dial or the panel of the receiver. Please outline some suggestions for the elimination of this body capacity.
A. The trouble may be due to one or more of several causes. Try grounding the negative A battery and the frames of the audio frequency transformers. Keep the grid wires as far back from the panel as possible, and be sure to connect the stationery plates of the variable condenser to the grid of the detector tube.
Q. Is there any way I can use the house current instead of my 6-volt storage battery to operate my radio receiver without changing any of the wiring in my set?
A. There are devices on the market which can be operated from the house lighting current for supplying both the A and B battery current necessary for the operation of a radio receiver. Your nearest radio dealer can supply you with complete and detailed information on the subject.
Q. What is the advantage in having a radio receiver which tunes from 40 to 200 meters?
A. The short waves-generally referred to as those below 100 meters-are a new field in which a great deal of research work is being carried out. Engineers in all parts of the world are experimenting with short-wave transmitters and receivers for both code and broadcasting, and a receiver which will tune to the lower wave lengths will frequently pick up signals from foreign stations. Stations KDKA and WGY broadcast their programs simultaneously on both their normal broadcast wavelengths and also on 96 meters and 100 meters, respectively. The average broadcast receiver will not tune to wave lengths below 200 meters.
If you are interested in experimenting you can construct a set which will cover the lower band of wave lengths. Constructional data on such a set appeared in the Radio Department of the January, 1926, COUNTRY GENTLEMAN, and reprints of this article, together with a list of short-wave stations, may be obtained upon application to the Radio Editor.
Q. I have often read that it is important to keep the tops of dry B batteries clean. Please explain the reason for this advice.
A. If dirt and dust collect on the wax surface of dry batteries they absorb moisture and, as a result, a slight leakage of current will take place through the path thus established. It is advisable to have a cover of some kind for these batteries or else clean them frequently.
Q. I have a three-tube regenerative receiver which employs two variometers and a variocoupler, also a variable condenser. I find it impossible to tune in the higher-wave broadcasting stations. I have tried various remedies but all have failed. My antenna is 80 feet long and the lead-in is 30 feet in length. What can I do to increase the wave-length range of the set?
A. Replace the grid variometer with one of a larger size. It may also be necessary to add wire to both the primary and secondary coils of your variocoupler. The circuit you are using is out of date. You would obtain the desired increase in wavelength range and probably very much better results by removing the variometers, variocoupler and variable condenser entirely from the set and replacing them with a three-circuit tuner of modern low-loss design and a straight-line frequency variable condenser to tune the secondary.
Q. I have a three-tube radio set which has been working quite well until recently. I used to get quite a number of stations loudly and clearly, but lately even the loudest of them can barely be heard. My batteries are new and I cut down my antenna, but the results are the same.
A. The symptoms you outline indicate that your tubes undoubtedly need reactivation. Take or send them to your nearest radio dealer for testing and reactivation or else replacement.
And we use an oscillating magnetic field to excite or move the electrons to generate radio waves. If you use heat to excite and vibrate the electrons, the emissions show up as light. That's the key principle behind incandescent light bulbs.
We've seen how we use electric current to generate a (magnetic) radio wave, and used the model of the pond to visualize the big picture and see basics of wave generation and propagation. Next month, we'll look at how we can use this simple model of a radio wave to improve our ability to anticipate and enhance radio communication and thereby add enjoyment to amateur radio.
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THE END