Glenn Hauser's SW/DX Report
Don Schimmel's Radio Intrigue
Joe Carr's Tech Notes
Frequency vs. Wavelength
Modes and Modulation
Call Sign Prefixes
Introduction to Shortwave Listening
Tuning 150 kHz to 30 MHz
Selecting a Shortwave Radio
Reporting and QSLs
Modern Shortwave Receiver Survey
Favorite Tube-Type Shortwave Receivers
Introducing the "Action Bands"
The World Above 30 MHz
Selecting a Scanner
National Scanner Frequency Guide
Other Radio Hobbies
AM Band DXing
Top of Page
The short wave listening (SWL) hobby is great fun. Please remember that first line, especially the word "fun". Further, SWL'ing is "a hobby". Fun and hobby are the two common threads that bind these Tips & Tricks together. We hope they are of some value. Time and resources will not allow for my personally answering every inquiry. However, questions received on particular issues in significant numbers will be addressed.
Shortwave Books Everyone Should Have.
Passport to World Band Radio. Consider this book to be a must have for every SWL. This publication contains a wealth of information for every SWL. Of particular interest for our purposes here, we direct your attention to the receiver and other equipment reviews. These equipment reviews, including those of current receivers are most helpful and very well done. Passport uses a team of experienced and dedicated SWL's for equipment review purposes and, for receiver reviews, use real life SWL antennas. They also use a real test lab to further qualify and quantify performance of that equipment. All very important. Unfortunately the 2009 was the last year this publication was printed, and its future status is uncertain.
World Radio TV Handbook. This respected annual serves both the hobbyist and the commercial international broadcasting audiences.
Shortwave Listening Guide Book. Harry Helms. No one quite says it like Harry! Most every aspect of the SWL hobby is contained in these pages. Need help with an antenna, wonder where to find the frequencies used by aero, marine or any other Utility Service etc.? Harry has the answers in this book. A good buy.
Passport RDI White Papers (receiver issues). These most useful publications are the more in-depth reviews of receivers that are contained in current and past issues of Passport to World Band Radio book mentioned above. These RDI White papers should be considered as additions to your receiver manuals. The material contained in these will not only help you understand your receiver it will also teach you many tricks of operation not contained in your manual. Again, these reviews are done by only the best SWL's and, they contain very detailed lab testing results.
Popular Outdoor Antennas, Including Installation. One more RDI White Paper and, the only currently available material about SWL Receive Antennas! Everyone needs this booklet. There are many books available addressing the subject of antennas. But, only this one book targets SWL antennas. Most all other articles and books cover antennas from the perspective of use for transmitting. There are many differences between transmit and receive antennas. More about SWL receive antennas will be addressed later in these Tips & Tricks. For now SWL's would be very well advised to read this White Paper. Also, there are many SWL receive antenna articles in older editions of The World radio & TV Handbook, especially the 1995 WRTH Buyers Guide.
Just a Bit About Shortwave Portable Receivers
I have never met a receiver I didn't like, especially the portables. But, there is no one perfect receiver, portable or otherwise. There are some portable receivers made better than others, but they cost more too. Performance of any portable receiver is dependent upon two simple factors, the user's understanding of RF and, the antenna used to feed signal to that portable. But, using large antennas on portable receiver's can not only degrade their performance it can ruin them.
Portable receivers come with built in whip antennas for use on the SW and FM broadcast bands and a ferrite rod for medium wave signals (MW). That is their design intent. We'll begin with a few tips & tricks for improving upon signal control and antenna use with the portable receivers. Later on we'll address certain operational tricks for specific portables and other receivers. No discussion about antennas and receivers is possible without covering a few basics. Among the basics needed for these topics are sensitivity (ability to hear) of the portable, signal to noise ratio of the received signal and the S-Meter.
Many, if not most SWL's will always ask about a receivers sensitivity, meaning how small of an RF signal is needed in micro volts are required to hear weak signals. On it's face this seems like a proper concern. But, sensitivity is a double bladed sword. Higher sensitivity can cause more problems than lower sensitivity in the form of receiver overload and intermodulation (both are unwanted). Given a choice I'll chose a receiver with a lower sensitivity every time. You can more easily manipulate and control a signal entering a receiver. Not so once that signal/noise enters your receiver. Proper antennas and devices give you that all-important "element of control".
Signal to noise ratio.
The ratio of the signal vs. the corresponding amount of noise that enters a receiver while you are trying to hear a given thing is the most important concept to be understood. All wanted signal entering your receiver will be accompanied by a corresponding amount of noise! The art of hearing the desired signal is won or lost through the concept of "knowing how to increase the signal at the expense of the noise". The antenna has the major role in this S/N ratio!
Second only to antennas, the S-Meter tends to cause the most SWL confusion! Many SWL's believe that for good reception the signal meter must be all the way to the top of it's scale, or close thereto. That concept is very wrong. It is amount of audio you hear, and the quality of that audio that counts, nothing else. The higher the s-meter also the higher the noise. Only bring in enough signal to allow for good audio and ignore the s-meter. The s-meter will have uses later on. Concentrate on audio quality, not signal strength.
Antennas for Portable Receivers.
Portable receivers will perform very well using their already provided antennas. Keeping in mind the potential to overload, or even harm a portable receiver here are some tried and true antenna improvements.
(1) There are two primary sources of noise that impede our ability to hear our wanted signals, interior noise (inside the receiver) and exterior noise. We can only control exterior noise, the noise in our listening environment.
(2) The best way to control exterior noise is (gulp) "to whenever possible use an antenna not inside of the listening area" ( your home/office). Until and unless one learns the hard won fact that antennas outside of a house or building always out perform indoor antennas, first try wrapping three or four wraps of any old "insulated wire" (bare wire will short out) around the whip and snake about 15 feet or so feet around a window. Doing this has the effect of making the length of the whip longer and therefore to capture more signal. Again, too much wire will cause bad things, overload/intermod.
(3) When possible put a small insulted wire outdoors. Using 15 to 20 feet of wire outside 10 to 20 feet high will do very well. To bring the wire inside, open the widow, place a length of weather stripping (felt or foam rubber) along the length of the widow sill so as not to damage nor short out the wire, then connect it to the whip and shut window. Some portables have "mini jack or RCA phono" antenna inputs. Try using both and pick the one that sounds best! Note: You'll now find why I've warned against big antennas on portables. As a safety precaution against the use of potentially damaging big antenna the manufactures put a switch here to turn off the amplifier to the whip inside if the portable. That amp off reduces signal strength (to test this just stick your head phone jack into the antenna input while a strong signal is present).
(4) Use "the Wagner Active Preselector" antenna! (see Active Preselector at end of this section)
(5) Buy a Loop Antenna. Loop antennas work very well with all portable receivers (and many other receiver types seen later on in these pages). Some excellent loop antennas are readily available. Among the best are the former model AOR LA-320, current model AOR LA-390, also the former Kiwa Pocket Loop (more on this great Kiwa later also), or former Palomar Loop. There is also the excellent Palstar LA30 medium wave loop antenna that features an optional Tropical Band element (but covers only 1480-7500 kHz). It is also possible to build your own loop antenna, but not advisable for newbie's.
The best performing of the indoor antennas are the loop antennas. As my house is quiet now that the kids are raised and I'm retired I use the three commercial loops listed above plus the discontinued Sony ANLP-1. The first three loops listed above all work in a similar way and are very effective. Excepting for the Kiwa Pocket Loop and the Sony ANLP-1, the loops will have special plug in units called "lop heads". Each separate loop head covers a section of frequencies and you buy various loop heads depending upon the Bands you wish to tune.
The advantages of the loop antenna are many. The loop antennas are small and therefore can be rotated while sitting next to the portable so as to locate the best angle of signal arrival and to "null out" noise. Also, they employ a variable capacitor that allows you to "peak the signal" you are tuned to "reject" signals not desired (this is called "preselection"). This ability to "peak and null" makes the loop antenna a great choice and to not require one to be as apt to need an outdoor antenna, parish the thought. Loops are also very safe to use. The Kiwa Pocket Loop does not require "plug in loop heads". The changing of bands is done by adjustment of some five DIP switches inside the control box. The Kiwa can also tune higher in frequency than other similar loops. The Kiwa can even be used on older table tops without the need for power or peaking at every frequency change (little known tip). The new Sony AN-LP1 loop is a good performer and looks for all the world like a giant ping-pong paddle made of cloth! Don't let the looks fool you as it works very well when stuck on a window!
(6) Commercially made antennas for portables are available and also work very well. The active antennas (active means the use of amplifiers and power supplies to enable the use of a small receive element such as a whip) that work well with most all higher price portables are the RadioMasters A-50 or RadioMasters A-108 (The A-108 covers BCB-FM also) or the Sony AN-1. I use all of these and they do very well for active antennas (see "active vs. passive antennas" later).
Some great passive antennas for portables are the RF Systems EMF, RF Systems Mini-Windom, or the former RF Systems EMF-P wire antennas. These three different antennas are well made, weather proof for outdoor use, super easy to install (use weather stripping on window to feed in) and work very well. In fact, if you like MW DX you'll need to see "MW DX" later in these pages). The EMF antenna has two 35mm film canister looking objects connected to it. The canister on the far end is actually an excellent "tuned ferrite rod" designed for MW (medium wave) and really helps any receiver without a built in MW antenna rod. Canister two (in middle) is a balun that helps SW reception very much.
(7) "The Wagner Active Preseletor Antenna". No, I am not the inventor of this great SWL antenna! But, I use them so often with my patients, and have explained to so many SWL's how to use one of these I've been forced into finally putting the design/use to print! In fact, it was this antenna that caused me being drafted into doing these pages (a labor of love). Also, this antenna could legitimately be called "the if you want to make any receiver, in any tough location work better"antenna! This one is my absolute favorite, but I get to make a few rules "that no one is gonna change"! If the SWL's do not learn one other thing in this article it is going to be:
(A) A preselector and a "tuner" (ATU, Match box etc.) are two COMPLETELY DIFFERENT devices! A "preselector, in the words of one of my SW Idols-John Wilson (formerly of Lowe Ent., UK), is "an RF Gate". When a "preselector" is properly set it only allows a very narrow swath of RF in and severely attenuates all others. The design purpose of a preselector is to allow the receiver operator to select the signals they want to enter their receiver by deselecting all other signals. This RF "selection/de-selection" only allows the set narrow swath of RF into the signal processing circuits of the receiver. Absent those other "out of band strong signals", you vastly improve the Signal-to-noise ratio and get a cleaner audio.
(B) The so called "Tuner" is an altogether different device, having the design capability and intent on adjusting the antenna impedance "as seen by the in put/out put's of a transceiver! While there may be some value in the use of an ATU for SWL'ing, it is very limited. Transmitting is not a subject to be broached here.
(C) The last rule is "there are but two reasons under which this antenna will not work! Reason one for this not to work is "where ever the wire is located is already noise polluted (lots of interference in the location). Reason two for it's failure is "Pilot Error". Number two is by far the most common problem, as the proper use of any device requires careful adjustment.
What is needed for making "the Wagner Antenna".
(1) A 20 foot or so long piece of insulated stereo or hook up wire (try to buy the wire at Sears, Best Buy, Circuit City of similar audiovisual store. It comes already to use with RCA phono jacks in each end for connecting to a preselector).
(2) An MFJ-1020B, or MFJ-1045C, Grove TUN-4A, Ameco TPA, or Palomar's P-508. These are all "preselectors". (older Palomar P-405 or P-408's are great too).
(3) One 18 inch to 2 foot mini-coax jumper cable to connect the two together.
Set-up and Use.
All of these preselectors share a common design design/use traits. Most can be powered by a 9 volt battery (not TUN-4 or Palomar P-508 or 408). All have the three same front panel adjustments. All will work well "if simple set up" is followed.
(1) Attach the 20 foot speaker wire to rear RCA or SO-239 marked "antenna in put" and connect the 18" jumper wire to "antenna out" on preselector. Connect mini-coax to receiver "antenna in put".
(2) With preselector off tune receiver to a known weak but hearable signal (try the signal you have always wanted to come in better).
(3) Set preselectors "gain" to 1/3 to ½ way on (9 to 12 o'clock). Set middle knob (the course preselection knob) usually marked "Band" in MHz that your receiver is already tuned to. The middle knob will have a range of freq.'s marked in a range of 4 or 5 positions such as 1.8 to 4 MHz, 4 to 10 MHz, 10 to 16 MHz, & 15 to 30 MHz, Chose the MHz, range you are tuned to. Turn the preselector on.
(4) Now, to "where the rubber meets the road"! Take the far right knob, usually marked "tune" (ignore the "silk screened numbers above this knob" for the most part as they are only intended to serve as guides, not the actual "Sweet Spot"! Slowly turn the "tune" knob back & forth along it's turning range. You will hear many weird noises and "one click" (usually, but not always a muted click). If you don't hear a click, you'll hear your once weak freq. "jump out" to your ear! That is "the Sweet Spot"! That is "what you are looking for! Lastly, ever so sloooowly rock that last knob back & forth until spot on! Set left "gain" knob to lowest setting needed to pleasantly hear your frequency!