Audio Database

T-300
Commentary

AM/FM stereo tuners that emphasize sound quality while improving basic electrical characteristics.

The front-end section combines a four link varicon, a dual-gate MOS FET, and an oscillator circuit with less harmonic distortion to improve sensitivity, various types of spurious mating modulation, and input resistance characteristics. This enables excellent FM reception in a wide range of areas from low-electric-field areas to ultra-high-electric-field areas.

An LC-tuned 5-stage tandem linear phase block filter with excellent phase linearity and ripple characteristics is used in the intermediate frequency amplifier stage. This filter is combined with an LC double-tuned filter and a newly developed wide-band discriminator, and the entire LC-based intermediate cycle is used as a selection circuit. This greatly reduces the total harmonic distortion and intermodulation distortion.

In order to improve the distortion factor, a discrete MPX circuit is used for the MPX circuit.

The attached equipment is equipped with an electronic muting circuit that employs an FET to eliminate shock noise during switching, a high-blend noise filter, an AGC circuit, a high-output multi-path detection circuit, and a coaxial cable connector.

In consideration of FM4ch broadcasting, a connection terminal for 4-channel decoder is provided.

The AM tuner consists of one stage high frequency amplifier and two stages intermediate frequency amplifier.
In addition, a muting circuit for AM and a noise filter capable of two stage switching have been added to make AM broadcasting more enjoyable.

The design is designed to match the pre-main amplifier of the L-300 series.

Model Rating
Type FM/AM Tuner
FM Tuner Section
Practical sensitivity of IHF 1.7 μ V
Two signal selectivity 75dB
Amplitude modulation suppression 53dB
Capture ratio 1.5dB
Image ratio 95dB
IF interference rejection ratio 100dB
Frequency characteristic Stereo : 20 Hz to 15 kHz
Total harmonic distortion factor 0.2%
Signal-to-noise ratio 75dB
Stereo separation 40dB(400Hz)
Carrier leak -66dB
Muting level Fixed : 5 μ V
Variable : 4 ~ 30 μ V
Antenna impedance Equilibrium : 300 Ω
Unbalanced : 75 Ω
Output voltage 1.7V
<AM Tuner Section>
Practical sensitivity of IHF 250 μ V/m
Image ratio 80dB
IF interference rejection ratio 80dB
Frequency characteristic Mono : 40 Hz to 5 kHz
Total harmonic distortion factor 0.6%
Signal-to-noise ratio 48dB
Muting level Fixed : 320 μ V/m
Variable : 140 ~ 1,000 μ V/m
Output voltage 400mV
<General>
Semiconductor used Transistor : 38
MOS FET : 2
Junction FET : 1 unit
IC : 4
Diode : 26 Units
External dimensions Width 485x Height 165x Depth 281 mm
Weight 9.3kg