Sony ST-2950SD tuner

FM Stereo/FM-AM Tuner

Features:

FET front-end

New, computer-designed uni-phase IF filters

Phase-Locked-Loop IC stereo MPX stage

Dolby noise reduction system for decoding Dolbyized FM broadcasts, and Dolby indicator light

Center station and signal strength tuning meters

Smooth flywheel tuning action

Wide, frequency linear dial calibration

FM interstation muting

FM discriminator output for future 4-channel FM

High blend switch

Automatic mono/stereo switching and stereo indicator light

Wooden side panels included

Sony's new ST-2950SD yuner is prieced in the budget range, but is built with advdnce electronics that mean high performance. For a very modest expenditure, FM listeners can enjoy the quality sound of the ST-2950SD, as well as the convenience of a built-in Dolby decoding system for FM

FM Section

The unit's FM front-end electronics, with FET design, yield high sensitivity and a high interference rejection capability. The intermediate frequency stage utilizes Sony's new uni-phase IF filters, providing high selectivity and, at the same time, low audio distortion. And for excellent FM stereo, the multiplex stage is built with a Phase-Locked-Loop IC, providing low distortion decoding and high stereo separation. At least 35 dB of separation is maintained at high and low ends of the frequency spectrum, while 40 dB is achieved at midrange frequencies. Overall FM performance ratings include a capture ratio of 1,0 dB , an Signal-to-Noise Ratio of almost 70 dB in stereo and more than acceptably good distortion figures.

For listeners who want an uncomplicated means of taking advantage of Dolbyized FM programs, the ST-2950SD provides simple, one-step decoding. When stations send out Dolbyized broadcasts, all that's required for decoding is to press the unit's Dolby button - no need to use an add-on noise reduction unit, and no need to be concerned about changing FM de-emphasis.

AM Section

A triple AM AGC circuit is just one aspect of AM design that makes the ST-2950SD produce far better than average AM sound. Hi-fi oriented ears will be able to hear AM-only programs without the usual levels of irritating interference.

Tuning

Tuning the ST-2950SD is simple and accurate, with ultra-smooth flywheel tuning action, frequency linear dial calibration and highly readable tuning meters to help zero in on the station. FM interstation muting cuts out noise, and a clean, human-engineered front panel provides ease of use-in both tuning and control.

Specifiactions

FM Tuner Section

Antenna Terminals:  300 Ω  balanceed; 75 Ω  unbalanced

Usable sSensitivity (IHF '58}:  2,0 µV

50 dB Quieting Sensitivity: 4,0 µV [mono] 50 µV [stereo]

Signal-to-Noise Ratio:  73 dB [mono] 68 dB [stereo]

Capture ratio:  1,0 dB

Selectivity:  50 dB

Image Rejection:  45 dB

IF Rejection:  90 dB

Spurious Rejection:  75 dB

AM Suppression:  54 dB

Harmonic Distortion

At 100 Hz :  0,2% [mono] 0,3% [stereo]

At 1 kHz :  0,2% [mono] 0,3% [stereo]

At 10 kHz :  0,2% [mono] 0,6% [stereo]

IM Distortion:  0,2% [mono] 0,3% [stereo]

Frequency Response:  30 Hz - 15 kHz +0,5 -1,0 dB

Stereo Separation:

At 100 Hz :  -35 dB

At 1 kHz :  -40 dB

At 10 kHz :  -35 dB

RF Intermodulation:  60 dB

Subcarrier Product Ratio:  60 dB

SCA Suppression:  60 dB

AM Tuner Section

Antenna:  built-in ferrite bar antenna w/terminal for ext.wire

Sensitivity: 

w/Built-in Antenna :  250 µV/m

w/ext. Antenna :  100 µV

Selectivity:  35 dB at 10 kHz

Signal-to-Noise Ratio 50 dB at 50 mV/m

Image Rejection:  40 dB at 1 kHz

Harmonic Distortion:  0,5% at 50 mV/m, 400 Hz

General

Output Level/Impedance ((at 100% modulation)

Audio (Fixed) :  750 mV/5 k Ω

Discriminator:  150 mV/2,5 k Ω

Semiconductors:  4 IC's; 1 FET; 17 Transistors; 14 Diodes

Power Requirements"  AC 120 V - 240 V 50/60 Hz

Dimensions (W x H x D):  390 x 145 x 310 mm (15-3/8" x 4-3/4" x 12-1/4")

Weight:  6 kg (13 lbs 4 oz)

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