What is stereo?




There are now two system of high fidelity, monophonic (monaural) and stereophonic. Monophonic is a system that starts from one microphone and is fed through a single high fidelity set. Stereophonic is a double system. Two separate microphones are placed at different sides of the orchestra and two different systems are used to keep the two signals or channels separated. Two separate speakers are used, placed on different sides of you room. Stereo is much like 3-D photography, two slightly different sound reach your ears giving you a new dimension in sound.




H.H. Scott '59





NAD 402 Tuner


The Model 402 embodies NAD's conviction that convenience, flexibility, and ease of use can be achieved with absolutely no compromise in sound quality. The 402 has AM and FM; preset distortion-free tuning for 60 radio stations

60 Presets 30 AM and 30  FM radio stations
NAD-Link Connectors allow control to and from other units
Blend facility to reduce noise at low signal strengths
75 Ω coax antenna connector
Lock facility to automatically tune precisely onto a station
Three separate modes of tuning with 25 kHz accuracy

Flexible Tuning
The 402 has three convenient tuning modes:
Search: Scans rapidly up or down in frequency, stopping automatically at the next strong station.
Preset: Up to 30 FM and 30 AM station frequencies can be stored in memory and instantly recalled. The "non-volatile" memory needs no battery or other power; frequencies are retained during power outages, even if you unplug the receiver for weeks at a time.
Tune: Dual-resolution tuning lets you scan rapidly through the broadcast band (with constant pressure on an up/down tuning button), or fine-tune in small 0,025 MHz steps by tapping on the buttons. This lets you optimise the reception of a weak station adjacent to a strong one.

Sensitive Digital Tuning
Precise digital frequency-synthesis circuits guarantee that each station is tuned with crystal-controlled accuracy. A dual-gate MOSFET FM circuit pulls in weak stations clearly but resists overloading on strong signals. A balanced quadrature detector provides consistently low distortion, even with over-modulated broadcasts. The composite stereo signal is phase-compensated to guarantee wide stereo separation at all frequencies, not just in the midrange.

Sharp selectivity, low noise
Linear-phase ceramic filters in the I.F. circuit provide an ideal combination of sharp selectivity and minimum distortion. Low-loss design gives the optimum signal level to the PLL MPX decoder, yielding a signal-to-noise ratio of nearly 75 dB with strong signals. So with local stations the ultimate stereo guieting is limited not by the receiver but the station itself.

Specifications
FM Tuner Section
Input Sensitivity:
Mono (-30 dB T.H.D.+N) :  1,3 dBf (1,0 µV/75 Ω)
Mono (-50 dB SN) :  15 dBf (1,5 µV/75 Ω)
Stereo (50 dB SN) :  37 dBf (20 µV/75 Ω)
Stereo (60 dB SN) :  47 dBf (60 µV/75 Ω)
Capture Ratio:  less than 1,6 dB (45 to 65 dBf)
AM Rejection:  more than 60 dB (45 to 65 dBf)
Selectivity: 
Alternate Channel:  58 dB
Image Rejection:  70 dB
RF. Intermodulation:  60 dB
I.F. rejection:  90 dB
Subcarrier Suppression:  60 dB (19 and 38 kHz)
T.H.D. at 100% Modulation
Mono (1 kHz):  0,1%
Mono (100 Hz - 6 kHz) :  0,2%
Stereo (1 kHz) :  0,1%
Stereo (100 Hz -6 kHz) :  0,3%
Signal-to-Noise Ratio (at 65 dBf, IHF weighted)
Mono :  better than 80 dB
Stereo :  better than 74 dB
Frequency Response 30 Hz - 15 kHz:  ±0,5 dB
Stereo Separation:
1 kHz :  45 dB
30 Hz - 10 kHz :  35 dB
AM Tuner Section
Usable Sensitivity:  5 µV
Selectivity:  30 dB
Image Rejection:  45 dB
I.F. rejection:  35 dB
Signal-to-Noise Ratio (30% modulation, 50 mv Input):  45 dB
Total Harmonic Distortion:  0,5%
Physical Specifications
Power Ratting:   120,, 220 0r 240 V, 50/60 Hz
Power Consumption:  150 W
Dimensions (W x H x D):  420 x 91 x 273 mm
Weight [net/shipping}:  6 kg/7,1 kg

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