WRP_BetterTogether_Mar15_3v_Layout 1 3/28/15 1
We’re Better Together!
THE WORLD OF RAILROAD RADIO BY VINCENT REH Do-It-Yourself Antennas
FOR MANY RADIO ENTHUSIASTS, antenna con- struction is one of the most enjoyable aspects of the hobby — along with knob-twiddling and button-pushing, of course. Several fac- tors have led to an increased interest in an- tennas and antenna building; for one, mod- ern component technology and equipment production methods make it very difficult or even impossible to build electronic products at home. Contrast this to days past wherein discrete components with wire leads such as resistors, transistors, capacitors, and elec- tron tubes made it relatively easy to connect, plug in, and solder parts to complete a kit or “homebrew” project. This trend not only affected individuals, but kit-producing com- panies as well, such as Heathkit who exited the kit business in 1992. Without electronics to build, many hobbyists turned to antenna building to fill the void. The widespread availability of good, web-
based information on antennas and antenna construction has also nurtured the trend to- ward building and experimenting with ae- rials of all types, including those for radio scanners. Perhaps the most important factor influencing the popularity of antenna build- ing is that anyone with common hand tools, ordinary fastening hardware, basic construc- tion skills, and the ability to “scrounge” and adapt everyday items — or to spend few dol- lars to purchase specialty parts — can build functional antennas for base and mobile use. These antennas aren’t subpar performers, ei- ther. They work great, giving you the satis- faction of knowing that you built something useful every time you pull in a distant defect detector, rail yard, engine crew, or base sta- tion.
Railscanners use three antenna types:
The best railroading magazines are now together under one roof! Whether you’re looking to stay current with the latest new products, build detailed scale models, head trackside to get close to the action, or relive the glory days of railroading, White River Productions has something for you. Get on board today!
(877) 787-2467
WHITERIVERPRODUCTIONS.COM P.O. BOX 48, BUCKLIN, MO 64631
60 AUGUST 2015 •
RAILFAN.COM
base, portable, and mobile. All can easily be built at home. Because of the stationary na- ture of base operations — such as a home listening setup featuring a base station scan- ner — antennas for this application tend to be permanently mounted and are larger than their mobile and portable counterparts. The freedom from space limitations makes it possible to install large, powerful direction- al antennas (also known as beam antennas) that can be aimed at transmission sources to maximize reception. However, directional an- tennas can also be used with portable setups on an ad-hoc basis in the field to increase por-
This dipole scanner antenna can be easily con- structed using scrap wire and salvaged spool- type insulators such as those found on old electric fences, in fl ea markets, and at garage sales.
table listening range. In this application, hob- byists often clamp the antenna to a makeshift mast, such as length of bannister stock, using muffler clamps and thumbscrews to get their antenna higher into the air. When constructing directional antennas,
Example of a homebuilt ground plane scanner antenna using solid wire and a coaxial cable socket. Antenna elements are constructed of solid wire scraps and are actually longer than shown. Plans for this popular antenna and the others illustrated here are available on the web.
keep in mind that an antenna having more el- ements (signal gather- ing components) will be longer but will typical- ly pull in more signals (have higher gain) than one with fewer. In this regard, you’ll see refer- ences to such things as “three-element beams,” “five-element beams,” and so on. However, the more elements a directional antenna has, the more carefully it must be aimed at the transmitter to maxi- mize reception. As with all things in life, you don’t get something for
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62 |
Page 63 |
Page 64 |
Page 65 |
Page 66 |
Page 67 |
Page 68 |
Page 69 |
Page 70 |
Page 71 |
Page 72 |
Page 73 |
Page 74