7
Stereo/mono
This receiver is fully equipped for the reception of FM
stereo broadcasts.
FM stereo broadcasting is based on the pilot tone system
which allows the program to be received in mono on mono
receivers without impairment of program quality. It is an
inherent property of this system that a stronger signal is
needed in stereo to obtain the same noise suppression as in
mono. The FM stereo decoder automatically switches to
stereo operation when a stereo signal of sufficient strength is
received. If the stereo signal falls below a preset threshold,
the program will be automatically reproduced in mono.
However, it is possible for the strength of a stereo signal to
be adequate and yet for the signal to be temporarily disturbed
by noise or distortion. In this event depress the FM MONO
button whereby the program will be reproduced in mono
without noise or distortion.
Because stereo reception requires a strong antenna signal and
is sensitive to multi-path distortion, a good antenna is needed
particularly under difficult receiving conditions and in fringe
areas. Read the preceding section on FM antennas.
Dolby* programs from FM stations
The Dolby B noise reduction system offers a po ssi bi l i t y to
combat the higher noise in FM stereo transmissions. The
system is in the USA approved by FCC** for FM
broadcasting.
The Dolby B system use a program level dependent
preemphasis. At high level the preemphasis is 25
μ
sec, at
lower level the preemphasis increases. The utilization of the
allowed modulation can thereby be improved. The
compatibility of the Dolby B system with existing standards
is considered acceptable as the average preemphasis obtained
in the Dolby B encoder matches the standard deemphasis. To
take full advantage of the Dolby B noise reduction, a Dolby
B decoder unit must be used and the deemphasis network in
the receiver must be corrected to 25
μ
sec.
For those who may receive Dolby B encoded FM broadcasts
we have found a switchable deemphasis to be a useful
feature, This serves two purposes. First: To enable the user
to utilize a separate Dolby decoder, for instance the decoder
already incorporated in Tandberg Tape Recorders 3600XD,
9200X.D and 10XD. Second; To enable a direct re-cording
of the Dolby B encoded program for later decoding when
played back through the tape recorder's Dolby circuits.
PROCEDURE:
When receiving an FM Dolby transmission and using a
Dolby B decoder, the FM 25 uS button must be
depressed. The button must also be
depressed when a direct recording of a Dolby B transmission
is wanted ***.
When receiving an FM Dolby transmission without using a
Dolby B decoder, the FM 25
μ
S button must be released.
*
The name Dolby is a registered trade mark of Dolby
Laboratories Inc.
**
FCC stands for Federal Communications Commission, the USA
broadcasting standards organization.
***If you are using a Tandberg Tape Recorder with Dolby, set the
Dolby knob of the recorder to DOLBY FM.
Summary of Contents for TR-2075
Page 1: ......
