Audio Database

The

ROTEL RT-2100
98,000 ( at the 1970 in-the-late time(?))

Description
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FM stereo tuner which adopted the Quartz nowait-lock scheme.

The Quartz nowait-lock scheme by a crystal oscillator is adopted.
The Quartz nowait-lock scheme is always comparing exact 10.7MHz generated from a crystal oscillator, and 10.7MHz of a middle cycle amplification (IF). When a difference occurs here, the difference signal of plus or minus is made by a phase comparator, and the local oscillator is controlled through a low pass filter. In order that Quartz may not receive influence in a transition of humidity or a temperature, either, a frequency of oscillation remains locked and the drift after a syntony is eliminated.
Moreover, the touch nowait-lock-off scheme is adopted, while touching the tuning knob, a nowait lock is canceled, and the Quartz nowait lock works at the moment of lifting a hand.

The tuning scheme by a LED indicator is adopted.
If a tuning knob is touched, the induced voltage will be detected and the Quartz nowait lock will be canceled. At this time, a local frequency changes linearly, and if it comes until the radio wave of choice has a near dial pointer (}100kHz), the indicator of a sub- will light up. Furthermore, if a pointer approaches the radio wave of choice, central green light emitting diode will light up, and having aligned completely is shown. If a hand is lifted at this time, it is shown that light emitting diode of Quartz locking-in Decatur shone with green, and changed into the status of a nowait lock.

The frequency linear-line type precision 5-unit variable condenser is adopted as a front end part.
Moreover, in RT-2100, the three dual gates MOS FET are used and a high sensitivity and stonewalling exclusion capacity to have excelled are realized.

The IF section can switch two steps of bandwidth, and the requirement setups according to receiving requirements is possible for it.
A high selectivity property is acquired by choosing NARROW, when a radio-wave status is bad.

The carrier cancellar circuitry which omits a pilot signal (19kHz) is carried in the MPX section. Moreover, by adoption of LC block filter and PLL IC which paid attention to the damping of the subcarrier signal (38kHz), the high region fall was suppressed and a wide range is secured.

The tape-deck level checking functionality is carried.
If a REC CHECK switchpoint is turned on, 400Hz dial tone will come out. At the time of an air check, this signal is set as criteria (0dB) for the level of the deck.

The multipath detection functionality is carried.
In RT-2100, the degree of a multipath is displayed with a signal indicator.

The high blend switchpoint which demonstrates power is carried in the reception of a weak-electric-current community.


Rating of a mode
Form FM stereo tuner
Sensitivity (IHF) mono: 9.3 dBf/1.6 microvolts (S/N 26dB)
stereo: 36 dBf/35 microvolts (S/N 50dB)
S/N ratio (IHF) mono:80dB
stereo:75dB
THD
mono wide:0.05%
narrow:0.15%
stereo wide:0.07%
narrow:0.2%
Capture ratio 1dB
Effective selectivity (IHF) narrow:80dB
Frequency characteristic 30Hz-15kHz}0.2dB
Stereo separation 47dB(1kHz)
Image stonewalling ratio 115dB
IF stonewalling ratio 115dB
AM supression ratio 65dB
Muting 5 microvolts
Dimensions Width 482x height 143x depth of 328mm
Weight 7.5kg