Technics ST-7300

 FM/AM Stereo Tuner

There are many high fidelity enthusiasts who seek the quality and control features of a separate tuner, but are put off by the prohibitive prices of "separates". For them, the ST-7300 is the perfect answer. It yields a flat frequency response curve from 20 Hz to 15 kHz, with a low 0,4% total harmonic distortion in stereo, excellent sensitivity and selectivity figures, and a 75 dB signal-to-noise ratio. The ST-7300 demonstarates the high degree of performance that can be enjoyed at a very reasonable cost.

 Test Signal Generator for Perfect FM Recording Level Settings

Accurate level adjustments are critical in FM taping. The St-7300 eliminates the guess work with a built-in test signal generator whose output corresponds to 50% of FM signal modulation. Simply switch on the 440 Hz pure sine wave generator and set the tape recording level.

Direct Antenna Connections

The antenna terminals are connected directly to the circuit board of the front end, without intervening wires. The results are an extremely good sensitivity, and excellent spurious and image rejection.

3-Ganged Capacitor FM Front End

The high S/N ratio and sensitivity of the ST-7300 are due in large measure to the FET and 3-ganged capacitor used in the first stage of the front end.

 Flat frequency Response Over  A Wide Spectrum, 20 Hz - 15 kHz (+0,2 dB, -1,0 dB)

The remarkably flat frequency response curve over a broad range of frequencies is made possible by use of Chebyshev-characteristic low pass filters. These filters also attenuate the 19 kHz pilot signal to a level at which it will not interfere with the audio signal.

Flat Group Delay Filters in IF Stage

Three 2-element flat group delay ceramic filters in IF stage contribute to the tuner's excellent sound fidelity as evidenced by a total harmonic distortion of 0,4% (stereo), and S/N of 75 dB. Five differential amplifiers give high gain and an impressive selectivity rating of 75 dB (IHF).

Two Tuning Meters

The zero-center meter indicates exact center of channel tuning on FM. The signal strength meter works for both AM and FM. When used together, these two meters make FM tuning a simple matter. Quadrature demodulation by an integrated circuit assures meter linearity right up to the 60 dB (1000 µV) input level.

 PLL  FM  MPX  Decoder

A phase locked loop provides the 38 kHz time switching signal by which the two channels of FM MPX broadcasts are decoded. The phase comparator and feedback techniques employed interlock both frequency and phase of input and output signals to provide clearly defined channel separation despite temperature and humidity changes.

Sensitivity 1.0 µV at S/N 20 dB (75 ohms)

The ST-7300 offers a truly amazing sensitivity; full 1.0 µV at ±40 kHz deviation. Even more important, 46 dB quieting level can be reached with a signal strength of 19 µV (75 Ω) in stereo.

When using an outdoor antenna with the ST-7300 a coaxial cable (75 Ω impedance) is recommended.

Specifications

FM Tuner Section

Frequency Range:  88 - 108 MHz

Sensitivity (±40 kHz deviation)

S/N 30 dB :  2,0 µV (300 Ω), 1,4 µV (75 Ω)

S/N 26 dB :  1,8 µV (300 Ω), 1,2 µV (75 Ω)

S/N 20 dB :  1,5 µV (300 Ω), 1,0 µV (75 Ω)

IHF Usable Sensitivity :  2,0 µV

S/N 46 dB quieting Sensitivity:  19 µV (75 Ω, stereo)

Total Harmonic Distortion:

Mono : 

0,2% at 100 Hz,

0,2% at 1 kHz

0,5% at 100 Hz

Stereo :

0,4% at 100 Hz,

0,4% at 1 kHz,

0,5% at 6 kHz

Signal-to Noise (±40 kHz Deviation)

Mono :  69 dB (75 dB,IHF)

Stereo :  65 dB ,( 70 dB IHF)

Frequency Response:  20 Hz - 15 kHz (+0,2 dB, -1,0 dB)

Alternate Channel Selectivity:  75 dB

Capture Ratio:  1 dB

Image Rejection at 98 MHz:  55 dB

IF Rejection at 98 MHz:  82 dB

Spurious Response Rejection at 98 MHz:  80 dB

AM Suppression:  55 dB

Stereo Separation:  45 dB (1 kHz);  35 dB (10 kHz)

Leak Carrier:  -60 dB (19 kHz, 38  kHz)

Channel Balance (250 Hz - 6300 Hz ) ±1,5 dB

Limiting Point:  1,2 µV

Bandwith:

iF Amplifier :  200 Hz

FM Demodulator:  820 kHz

Antenna Terminals:  300 Ω, 75 Ω

AM Tuner Section

Frequency Range:  525 - 1605 kHz

Sensitivity 30 µV, 260 µV / metr

Selectivity:  20 dB

Image Rejection at 1000 Hz:  45 dB

IF Rejection at 1000 kHz: 40 dB

Output Voltage and Impedance:  0,5V / 4,7 k Ω

Power consumption:  11 W

Power Supply:  50/60 Hz; 110/120/220/240

Dimensions (W x H x D):  410 x 139 x 317 mm (16-5/32" x 5-15/32" x 12-15/32")

Weight: 5,1 kg (11,2 lbs)