Audio Database

TU-9900
Commentary

An FM/AM tuner that thoroughly pursues the receiving performance of a tuner in order to ensure stable reception in all radio wave conditions. At the same time, an FM/AM tuner that incorporates excellent circuit technology and carefully selected materials in order to achieve both audio performance and reception performance.

The front-end section uses a linear frequency type FM5 series varicon, three low-noise dual-gate MOS FETs, and one transistor. It is also equipped with an antenna attenuator switch, enabling stable reception even in long-distance reception areas and short distances with strong electric fields.

The IF section is equipped with a reception band switching function, so that both sound quality and reception performance are emphasized.
A two stage 6-pole block filter with flat group delay characteristics is used for wide-band signals with an emphasis on sound quality, and a narrow-band 4-pole ceramic filter is used for reception with excellent adjacent interference rejection capability for narrow-band signals.

The ultra-wide-band ratio detection circuit and MPX section use a differential demodulation circuit and PLL (phase-locked loop) system with excellent phase characteristics, which provides good linearity over a wide bandwidth and a low distortion factor equivalent to that of a pre-main amplifier.

Equipped with an auto noise canceler that employs a photo-coupler. When a weak signal is input, the amount of blending to the left and right is automatically changed according to the signal level to cancel the noise, thereby improving the practical listening performance.

The AM tuner uses a double-tuned circuit and a Yaman type ceramic filter with two elements and two coils to improve sound quality and selectivity.

Each block stage uses a stabilized power supply with ± 2 power supply of good regulation to improve stable operation and sound quality.

Built-in test oscillator for recording that can easily set the appropriate level on the deck.
The signal is 1 kHz with a level of -10dB at 100% FM, and can be used to check the phase of the speakers and adjust the left / right balance.

A low-pass filter with sharp characteristics is installed to avoid the beat with the deck.

Equipped with an output terminal for recording only.

Signal meter and center tuning meter are used.

Equipped with a flexible AM bar antenna, multi-path observation terminal, FM detection output terminal, 75 Ω F type FM antenna terminal, and output level adjustment function.

Uses a heavy class sintered alloy flywheel and a dial face made of glass that does not change over time.

Model Rating
Type FM/AM Tuner
FM Tuner Section
Sensitivity (IHF) 1.5 μ V
Total harmonic distortion factor
mono(wide): 0.06% or Less (1 kHz)
0.06% or Less (50 Hz)
0.08% or Less (10 kHz)
mono(narrow): 0.5% or Less (1 kHz)
0.5% or Less (50 Hz)
0.8% or Less (10 kHz)
stereo(wide): 0.08% or Less (1 kHz)
0.1% or Less (50 Hz)
0.15% or Less (10 kHz)
stereo(narrow): 0.8% or Less (1 kHz)
0.8% or Less (50 Hz)
1.2% or Less (10 kHz)
Signal-to-noise ratio Mono : 80 dB or more
Stereo : 76 dB or more
Selectivity
wide: 55 dB or More (400 kHz)
22 dB or More (300 kHz)
5 dB or More (200 kHz)
narrow: 90 dB or More (400 kHz)
60 dB or More (300 kHz)
20 dB or More (200 kHz)
Capture ratio Wide : 1 dB or less
Narrow : 3 dB or less
Image frequency rejection 100 dB or More (83 MHz)
IF Rejection 110 dB or More (83 MHz)
Spurious response rejection 110 dB or More (83 MHz)
Unwanted radiation 34 dB or less
Stereo separation 50 dB or More (1 kHz, wide)
30 dB or more (1 kHz, narrow)
40 dB or More (50 Hz, 10 kHz, wide)
Frequency characteristic 30 Hz ~ 15 kHz + 0.5 -0.8 dB
<AM Tuner Section>
Sensitivity 45dB/m(1MHz)
Selectivity 70 dB or More (1 MHz ± 10 kHz)
Image rejection 100dB/m(1MHz)
IF Rejection 100dB/m(1MHz)
Total harmonic distortion factor 1% or Less (80% modulation, 100dB/m)
<General>
Output voltage FM : 0 ~ 1 V (100% MOD)
Rated power consumption 20W
External dimensions Width 460x Height 176x Depth 310 mm
Weight 9.6kg