User Manual

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monitors), or you can try to relocate your antenna further away from your
computer.
A good remedy to try is to wind five to ten turns of the antenna lead-in cable
through a large ferrite core (the doughnut shaped toroid type), near the PC
end of the cable. This suppresses common-mode interference, which is a
typical but curable problem with PC-controlled receivers.
Another type of interference which you may encounter is intermodulation
interference. This is usually caused by strong local stations, whose
frequencies combine to create ‘ghost’ signals on frequencies which are
arithmetic combinations of the stations’ frequencies. These ‘ghost’ signals
can sometimes coincide with useful frequencies, rendering them partially or
completely unusable. They will usually disappear when you switch on the
Attenuator in the receiver control panel. You may also try shortening the
antenna.
If you live very close to a strong local transmitter, these measures may be
insufficient. In such case, you should be able to eliminate intermodulation by
fitting a special filter to your antenna, to reduce the level of the signals
causing the interference. The design and application of such filters falls
beyond the scope of this book, since the large majority of WiNRADiO users
should not experience this problem (after all, not too many of us live next
door to a radio station). However, broadcast frequency filters and tunable
preselectors are standard items and can be obtained from good radio
equipment suppliers.
Did you know?
The first shortwave transmission from space took place on October 4, 1957,
when the first Russian satellite, the Sputnik, was launched. The Sputnik
transmitted amplitude modulated signals on 20,008 kHz. The characteristic
beeping of Sputnik’s telemetry was listened to by millions, ushered in a new
era of political, military, technological, and scientific developments, and
marked the start of the US-USSR space race.