Sony icf 2010 - For Improved Reception; Tuning Using Synchronous Detection

FOR IMPROVED RECEPTION
ANTENNA ADJUSTMENT
For FM/AIR reception
Pull out the telescopic antenna to expose its swivel base and ad¬
just its length, angle and direction for optimum reception. For AiR
reception, extending two sections of the antenna is recommended.
See illustration (^-1 on page 4.
For SW reception
Pull out the telescopic antenna to its full length and set it vertically.
See illustration [^-2 on page 4.
• If there is a fluorescent lamp just above the set and reception is
noisy, incline and shorten the telescopic antenna.
For MW/LW reception
Retract the telescopic antenna. The built-in ferrite bar antenna ac¬
tivates. Since this antenna is directional, rotate the set horizontally
for optimum reception, if necessary. See illustration (G]-3 on page
4.
Notes
• If reception is unsatisfactory with the telescopic antenna or the
built-in ferrite bar antenna, connect an external antenna. To con¬
nect an external antenna, see page 18.
• In vehicles or in buildings, radio reception may be difficult or
noisy. Try listening near a window.
• If the received sound is distorted or noisy, adjust the antenna
carefully. For AM reception, set the AM ATT selector to LOCAL.
HOW TO SELECT AM MODE
Select the appropriate AM mode according to the broadcast or
receiving conditions.
WIDE NARROW SYNC USB LSB/CW
Seieoted AM mode
_
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I C L U,U «H,
WIDE; Normally set to this mode tor wider selectivity.
NARROW: If reception is interrupted or noisy, set to this mode for
narrower selectivity. Reception will be improved.
SYNC; If reception is difficult because of beats from adjacent sta¬
tions or distortion due to fading, which frequently occurs dur¬
ing AM (LW, MW and SW) reception, set to this mode and pro¬
ceed as in “Tuning using synchronous detection”.
USB: For USB (upper sideband) reception.
LSB/CW: For LSB (lower sideband) or CW (International Morse
Code) reception.
TUNING USING SYNCHRONOUS DETECTION
1 Tune in the desired station.
2 Press the SYNC key. The SYNC indication will be displayed and
the UPPER or LCWER SYNC indicator will light up.
3 Set the MANUAL TUNE MCDE selector to SLCW.
4 Turn the MANUAL TUNING knob slowly so that the other SYNC
indicator lights.
Choose the best possible tuning point, monitoring the received
sound.
MANUAL
TUNING
UPPER J
- • UPPER
SYNC -
SYNC-
• LOWER —jo'- LOWER
During tuning, a beat (whisling noise) may be heard when the ex¬
tremely weak signal is received. If this happens, repeat the steps 3
and 4.
To cancel the SYNC mode, press the SYNC key again. The SYNC in¬
dication will disappear.
-What is synchronous detection?
There are two big problems in AM reception: distortion due to
fading and interference from adjacent stations. The synchro¬
nous detection is effective to these problems.
Distortion due to fading is caused by overmodulation, which oc¬
curs when a carrier component of the received signal is at¬
tenuated on the way. In this receiver, a pure carrier frequency
with no level variation, perfectly synchronized with the original
carrier, is generated in the synchronous detector circuit and is
mixed with the received signal to compensate the attenuated
carrier component. In this way, distortion is remarkably reduc¬
ed.
On the other hand, AM (LW, MW and SW) broadcasting generally
uses double-sideband transmission, in which modulated signals
are transmitted using both the upper and lower sidebands (USB
and LSB). In most cases one of the sidebands is affected by in¬
terference from adjacent stations (beats). In the synchronous
detector circuit, one of USB and LSB can be received. This
allows clear reception without interference from adjacent sta¬
tions.
Carrier
adjacent station
received.
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