The Sony
ST-J88B is a quartz-locked frequency synthesized FM stereo tuner that just
happens to be one of the very finest FM tuners we seen in years. It is probably
the precursor of what to expect in the next generation of precision FM tuners,
for the ST-J88B is, in fact, the next generation. The sound quality is
exceptional, low frequency overload characteristics for more then 100%
transmitter modulation usually a problem in synthesized tuners, is similiarly
exceptional. Dual IF selectivity-normal (wide) and narrow is provided. Unlike
the usual dual selectivity which is fair (wide) and very good (narrow), this
tuner's selectivity is very good and outstanding; in the narrow mode we
received full band of signals on alternate spacing, hearing many signals we did
not even know existed (they are generally buried under alternate channel
interference). The frequency readout is a digital display, tuning is in
standard USA increments of 200 kHz. Seven memories are provided which remember
the frequency, desired selectivity, muting on or aff, and auto stereo or mono
mode. Labels for every frequency which
can be slipped behind the bezel above each memory selector, are provided. Other
features include a signal strength indicator directly calibrated in dBf
(received signal strength). There is no tuning device because the frequency
synthesizer is always precisely on the station frequency. There are three
tuning modes: Automatic - the FM band is scanned until a signal is received. Manual - frequency can be changed rapidly or
stepped on channel at a time. Memory - pressing one of seven buttons selects a
preprogrammed frequency and all its operating conditions. The memories are
non-volatile 9remembers programming) as long as the power cord is connected.
Specifications:
Input Level
(for Full Limiting): 3,0 µV
Mono Hi-Fi
Sensitivity (60 dB quieting): 9 µV
Stereo Hi-Fi
Sensitivity (55 dB quieting): 65 µV
Stereo
Frequency Response Range: 30 to 15,000
Hz
Stereo
Frequency Response Limits: 0/ - 0,5 dB
Distortion -
Normal Selectivity at Standard test:
Mono : 0,08% T.H.D.
Stereo
: 0,08% T.H.D.
Signal-to-Noise
Ratio (at Standard test level): 80 dB
Midband
Stereo Separation:
Normal
Selectivity : 40 dB
Narrow
Selectivity : 50 dB
Alternate
Channel Rejection (Selectivity): very
good
Maximum
Variable Output: 3,5 volts (level at
100% modulation)
Maximum
Fixed Output Level : 0,68 volts (at 100%
modulation)
Alternate
Channel Reject on Narrow Selectivity:
Outstanding
Mono
Distortion narrow Selectivity: 0,3%
T.H.D.
Stereo
Distortion narrow Selectivity: 0,15%
T.H.D.
Antenna
Inputs: 300 Ω antenna, 75 Ω antenna
(coaxial)
Dimensions
(W x H x D): 480 x 80 x 370 mm
Weight:6,6
kg
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