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PORTABLE SHORTWAVE
RECEIVERS WHAT TO BUY AND
WHY! A BEGINNERS
GUIDE
"This information has been
edited from information obtained from the RADIO
NETHERLAND Receiver Test Team"
You can
spend anything from US $ 50 to US $ 50,000 on a shortwave receiver.
But price is by no means the only factor to consider. First you
should decide what sort of listening you want to try. In Europe, you
are unlikely to hear a 10 watt station in Venezuela on a 50 dollar
portable. But conversely it would be foolish to buy a US $ 5000
communications receiver for simple listening to major international
broadcasters (e.g. BBC, Deutsche Welle, Voice of America, Voice of
Russia, Radio Netherlands, etc.)
Portable receivers
If you only listen to the stronger
international broadcast stations, general shortwave listening
including the Amateur Bands or if you plan to take a simple receiver
with you everywhere, then consider sets in this category. To avoid
disappointment, make a note of the following:
These receivers
give good and cheerful performance, but you must not expect too
much. Their size and weight is a given consideration, but that
should not be the only factor to
consider:
FACTS TO PONDER!
Some sets only offer PARTIAL coverage of the shortwave bands. If
you plan to buy such a set to listen to (a) particular station(s),
then check in advance that the set will cover the frequencies you
want to listen to. On some receivers the band coverage is incomplete
and some bands are missing altogether. Check out the frequency table
under Coverage below. This is already a serious disadvantage.
LOOK FOR CONTINUOUS TUNING OF ALL
BANDS OF INTEREST BETWEEN ABOUT 2.3MHZ AND 30
MHZ!
Ease of tuning is another
factor to consider! The shortwave bands are extremely
crowded and, due to the price range, the shortwave bands may be
cramped into a few millimetres on the dial. The sets listed here are
better than average in this respect, but if you find the job of
searching for stations difficult, go for a set that offers "digital
readout". This means the set displays the frequency it is tuned to,
rather like a digital clock. This eliminates most of the "guesswork"
as to where you are in the band. This is rather more difficult with
the conventional "point-and-dial"
system.
SOME radios do not have the facility for
single-sideband (SSB ) reception, so you can't listen to amateur
radio operators, radio teletype stations, morse code or utility
services. Selectivity (i.e. the ability to separate the station you
want from the interference) and dynamic range (see later notes for
an explanation of this term) are NOT good enough for picking out
very weak stations. Some receivers offer the Phase Lock Loop (PLL)
tuning systems. This means the set is generally more stable and
easier to tune than receivers using older techniques (such as Wadley
Loop). Sets offering FM (VHF) coverage, portability, built-in
clocks, and stereo adaptors for FM performance just add to their
price without offering better shortwave
reception. Points to
consider
Buy the best possible receiver
you can afford. You CANNOT expect $2000 performance from
a $200 receiver. You may be disappointed in the results of an
inferior receiver. Before assuming your present receiver is
useless, or that it needs upgrading, check your antenna facilities.
Do not always assume that a long (10 metres or more) random wire
antenna in the garden will work wonders. If your receiver is a
portable, you may find that such an antenna will cause too much
signal to be fed into the receiver's sensitive circuitry. This
results in overloading and the appearance of strange stations on odd
parts of the dial. For further information, look at the shortwave antenna
page on this web
site. NEVER expect
that by buying an expensive receiver you will be able to tune in
exotic countries with hi-fidelity reception. Shortwave signals have
to travel vast distances. The imperfections of the ionosphere that
forms part of the signal path lead to fading and distortion. As yet,
there is NO SUCH THING AS A "SUPER POWERFUL" receiver that pulls
rare stations in with "local" quality. It is far better to start
with an inexpensive set, learn about the shortwave bands,
propagation and the limitations of your receiver. If you decide that
international radio listening is interesting enough to start
pursuing weaker signals, upgrading is always possible
later.
NEVER let salesmanship at your local store talk you into buying a
receiver without at least a demonstration. There is still a serious
problem when it comes to getting advice from shop assistants, many
of whom are not aware of the existence of shortwave broadcasting
stations. Their main expertise is in video or hi-fi. If the salesman
(or -woman) cannot name a major international broadcasting station
you can hear on the set, or fails to give a convincing explanation
of terms like SSB, the chances are s/he is
bluffing!
NEVER buy a receiver in the hope that you can buy extra parts at a
later stage to upgrade its performance. Some more expensive
receivers can have modifications done, but these are the exception
rather than the rule. You CANNOT economically make a professional
receiver from a US $150 dollar portable! AVOID using the
receiver on batteries if there is an option of AC mains electricity.
Batteries are up to 1000 times more expensive per unit of
electricity than the household current supply.
Abbreviations and terms
used
kHz: kilohertz, MHz: Megahertz, GHz:
Gigahertz 1 GHz = 1000 MHz = 1,000,000 kHz . Wavelength (in
metres) = 300 divided by Frequency (in MHz)
In North
America, the medium wave band is usually referred to the "broadcast
band" or the "AM band".
Weight: This is given in grams (1 oz
= 28 grams). Unless stated, this weight is WITHOUT batteries!
AM: Amplitude Modulation (i.e. the type of signals found on
long, medium, or shortwave). MW: Medium Wave LW: Long Wave SW: Short
Wave
VHF: Very High Frequency. This term, prominent in
Britain, is now being phased out.
FM: Frequency Modulation
(i.e. mostly found on the section of the dial between 88 and 108
MHz.) Sets made in Eastern Europe, including Russia and for the
Japanese market often have a different FM frequency coverage.
NBFM: Narrow band FM (This does NOT imply that the set
can pick up the FM range between 76 and 108 MHz). This mode is used
by amateur radio operators on 10 metre ham band, and in VHF/UHF
portions of the spectrum. Some 27 MHz CB operators in Europe also
use this mode. You cannot use a narrow band FM position to listen to
conventional FM broadcasts - there is too much distortion.
AGC: Automatic Gain Control
BFO: Beat Frequency
Oscillator (needed for SSB reception)
FET: Field Effect
Transistor
IF: Intermediate Frequency
IC: Integrated
Circuit
LCD: Liquid Crystal Display
LED: Light
emitting diode display
Mains: Set can be powered from
household AC power supply.
PLL: Phase Lock Loop
SSB:
Single Sideband ( A must for listening to Amateur radio operators on most "Ham"
bands
Keyboard
Tuning: The set has a calculator style pad on
the front panel. If you want to tune in 6165 kHz, you simply press
the keys 6 1 6 5, and possibly an "EXECUTE" button. The set will
then automatically tune to that frequency. This is very handy when
moving about the dial fast, and also simplifies tuning for the
non-technically minded.
Coverage:
A
receiver that only tunes the "official" shortwave bands may be very
limiting. The "Radio Regulations" of the International
Telecommunications Union define the shortwave broadcast bands. At
the 1992 World Administrative Radio Conference, new bands were
created and existing bands were expanded. The band limits in the
following table reflect the WARC-92 agreements and broadcast band
expansions used on a non-interfering basis (e.g., the 41 mb starting
at 6890 kHz on a non-interference
basis):
Metre
Band Frequencies kHz
120
2300 - 2495
90
3200 - 3400
75
3900 - 4000
60
4750 - 5060
49
5730 - 6295
41
6890 - 6990
41
7100 - 7600
31
9250 - 9990
25
11500 - 12160
22
13570 - 13870
19
15030 - 15800
16
17480 - 17900
17
18900 - 19020
13
21450 - 21750
11
25670 -
26100
Although the allocations do
not become official until 2007, in practice many stations have
already started using the expanded portions under the motto "use it
or lose it." Additionally, there are a few stations that broadcast
outside the band edges above, e.g., Iran on 9022 and a number of
African stations around 9200 kHz. Clearly, receivers with continuous
coverage between 1.6 and 30 MHz are preferred.
Sensitivity: This is the ability to pick up weak stations. Most modern
receivers (especially portables) are sensitive enough. Those that
are not are mentioned. A good antenna is also important, but don't
assume that a long wire of 30 metres connected to a small portable
will allow you to pull in the weak stations better. The extra flood
of energy may well overload the simple front-end circuitry in the
receiver!
Selectivity: This is the ability to separate the station you want to
hear, from nearby interference. This is to a large extent determined
by the bandwidth filters installed, and their so called "shape
factor". The sharper the filters the better. The smaller the filter
setting, the greater the reduction in nearby interference, but also
the more muffled the audio quality of the station you are trying to
hear. For listening to weak stations, most users want filters 4.0
kHz wide or less.
Dynamic
Range: This is the receiver's ability to cope with
reception of a weak station with a powerful station close by (either
on the band and/or geographically). Sets in class C are more
expensive because of their above average dynamic range. Two
excellent portable receivers we endorse highly that fall within the
above range of specifications are made by SONY and SANGEAN. The
SONY ICF-SW7600GR is the best of the
two as reviewed by the Radio Netherlands Shortwave
Broadcaster.
  Click the picture to see it!
Click here
for more!
Recommended Excellent Reference
books!

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