FM Digtal Tuner
The mark VIII Digital Stereo Tuner sets new standards for FM quality at a moderate price. Utilizing the newest linear and digital technology, the Mark VIII has been designed to achieve broadcast quality reception with outstanding reliability. Based on monolithic linear-phase filters and phase-locked-loop stereo MX, the Mark VIII is permanently aligned to maintain minimum distortion and maximum interference-rejection characteristics,
An LED digital-readout display guarantees the precise logging of stations. This readout system is crystal referenced with an accuracy of 0,004%. Accurate tuning is further pinpointed by an illuminated dual metering system indicating both relative signal strength and center-of-channel tuning.
The purist will be more than satisfied by the crystal-clear reception, the wide-open stereo separation, the precise smooth operation, and the obvious excellence of engineering and construction.
Features
LED Display: Four 7-segmented ruby LEDs constantly display the exact station frequency received. Extremely rapid and smooth tuning is provided by the balanced 17-oz flywheel.
Meters: An illuminated two-meter system facilitates the precise station tuning desirable for optimum reception. One meter indicates the relative signal strength of the station on a logarithmic scale while the other defines center-of-channel.
Front End: The use of five-gang variable capacitor
3 MOSFET: RF front end results in a spurious response rejection of over 100 dB and an IHF sensitivity of 1,6 µV
IF Filters: Eight permanently-aligned, linear-phase monolithic IF filters assure 120 dB alternate -channel selectivity while enabling harmonic and intermodulation distortion throughout the pass band.
Limiters: Seven cascaded differential-amplifier IC limiters achieve 100 dB rejection and high impulse noise rejection
Stereo MX: PLL circuitry incorporated in a single IC automatically locks the phase of the MX subcarrier oscillator to the incoming signal which generates fewer intermodulation distortion products when listening to stereo
De-Emphasis Selector: A push-button on the front panel selects either 75 µsec standard FCC de-emphasis or the recently adapted 25 µsec de-emphasis used with broadcasts including special noise reduction systems
MX Switching: When an MX station is received, a computer-logic circuit automatically switches reception to stereo indicated by a front-window LED. This circuit automatically triggers reception back to mono when less than 4 µV of signal strength is present. A front-panel "Stereo Only" push button selects circuitry which locks out all reception other than stereo stations.
Muting: An ingenious station-skirt muting circuit eliminates off-channel interference. With the Mark VIII, muting is "thump-free" due to FET stereo audio attenuators. A two-position switch selects the threshold signal-strength level which will activate the mute circuitry. The most sensitive position has been factory adjusted at 2 µV for minimum station rejection.
Specifications
IHF Sensitivity: 1,6 µV
Total Harmonic Distortion (1 kHz):
Stereo : less than 0,20%
Mono : less than 0,15%
Noise: 70 dB below 100% modulation
Capture ratio: 1,5 dB
AM Suppression: 100 dB
Spurious Response Rejection: 100 dB
Image Rejection: 100 dB
Alternate Channel Selectivity: 120 dB
Stereo Separation: 45 dB at 1 kHz; 35 dB at 10 kHz; 30 dB at 15 kHz
Frequency Response; 20 Hz - 15 kHz ±0,5 dB
RF Drift: less than 15 kHz (±0,05%)
Rated Output and Load Impedance: 1,2 V RMS at 1500 Ω min.
Muting: 60 dB at 1 kHz with two step threshold control
Antenna Inputs: 300 Ω balanced and 75 Ω unbalanced
Tuning Aids: 4 digit 7-segment LED readout, logarithmic signal strength meter, channel-center meter
Circuitry: 3 MOS FET RF, 2 stage RF amp,; 5-gang var. Cap.; 7-stage diff. Amp. Limiter ratio detector; PLL MX , 19 kHz and 38 kh IC filters, FET muting
Semiconductor Complement: 18 ICs; 31 Transistors; 12 Diodes
Dimensions (W x H x D): 483 x 133 x 267 mm (19" x 5,25" x 10,5")
Weight (Shipping): 10,5 kg (23 pounds)
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