Audio Database

The

Kensonic Accuphase T-100
135,000 yen(September, 1973 release)

Description
 
No. 1 of the AM/FM stereo tuner which the Kensonic company (the present Accuphase) announced as P-300 and C-200 simultaneously as Accuphase series.

Since it is compatible in the opposite engine performance of the second page of the engine performance as a receiver, and the engine performance as audiovisual apparatus, the high frequency technology of that time newest and a new material were thrown in unstintingly, and the technical limit has been challenged.

In a front end, it goes into a high frequency magnification circuit from an antenna, it mixes with a local dispatch signal in a mixed circuit, and 10.7MHz intermediate frequency is made.
In this portion, they are a frequency straight line 5 continuous variable condenser, 2 stage tuning circuit, and an interstage full shield mechanism,In addition to circuit composition, such as a local oscillation buffer circuit, dual gate FET is used for a high frequency circuit and a mixed circuit, and the spurious disturbance ratio and the image ratio are raised by extending an input dynamic range.

It goes into an intermediate frequency circuit, amplitude limiting of the contiguity wave is removed, amplified and carried out, and the intermediate frequency signal made from the front end is led to a detection circuit.
Although the transformer and the mechanical filter were conventionally used for the selection element of this intermediate frequency circuit, in order to improve distortion just like [ other ] high-class audio amplifier, the 15 steps of phase straight line LC concentration type filter is developed newly, and it is used combining IC.

In order to restore to FM intermediate frequency signal to an audio signal without distortion, about 3 times as much 1200kHz broadband discriminator as the zone generally used is used for a detection circuit.

The phase lock loop recovery [ which does not carry out but synchronizes the phase and subcarrier oscillator of an input pilot signal automatically ] circuit which will carry out the tuning circuit by the coil and a capacitor entirely is adopted as the stereo demodulator which divides an audio signal into a stereo signal on either side.

Since distortion occurs and good reception cannot be performed, when there is a multipass (ghost) and it is especially stereo reception, in order to improve this, multipass meter is formed independently in [ other than a signal strength meter or center tuning meter ] the sub panel.
The stable reception is attained because directions of meter fix the direction of an antenna in the direction which becomes the minimum.

AM tuner part serves as a low distortion design by the design of a new detection circuit, research of the proper zone, etc.
Moreover, the front end and the intermediate frequency circuit have extravagant circuit composition which used MOS and J type FET.

A two-step type muting changeover switch, a stereo noise filter, an AM-FM independent type output level control, dial light control, etc. are prepared in the front sub panel, and multipass meter will be automatically turned on, if a sub panel is opened.



Internal

Rating of a mode
Form AM/FM stereo tuner
<FM monophonic characteristic>
Sensitivity S/N 40dB: 2.0 microvolts
S/N 50dB: 4.5 microvolts
IHF sensitivity: 2.0 microvolts
Saturation point S/N (200 microvolts) 75dB
Saturation point THD (50-microvolt input) 100Hz : 0.1% or less
1kHz : 0.1% or less
10kHz : 0.1% or less
Audio IM distortion (70Hz:7kHz=4:1) 0.2% or less (1mV of antenna inputs, 100% abnormal conditions)
Frequency response 20Hz-15000Hz+0 -1 dB
The degree (IHF) of 2 signal selection 70dB
Capture ratio 1.5dB
Image ratio 100dB
IF disturbance ratio 100dB
Spurious disturbance ratio 100dB
AM oppression ratio (1mV input) 60dB
Frequency stability ±30kHz
Frequency accuracy Less than ±0.1%
Output voltage (100% abnormal conditions) 2.0V
<FM stereo characteristic>
Sensitivity S/N 40dB: 20 microvolts
S/N 50dB: 45 microvolts
Saturation point S/N (2mV input) 70dB
Saturation point THD (500-microvolt input) 100Hz : 0.2% or less
1kHz : 0.2% or less
10kHz : 0.5% or less
Frequency response 20Hz-15000Hz+0 -1 dB
Stereo separation 100Hz:35dB
1kHz:45dB
10kHz:30dB
Stereo change inlet pressure 5 microvolts, 20 microvolts (a muting switch and interlocking change)
SCA disturbance ratio 60dB
19kHz, 38kHz disclosure -70dB
<AM tuner part>
Sensitivity Distance: 15 microvolts
Local: 150 microvolts
S/N (a 1mV input, 1kHz, 30% abnormal conditions) 50dB
THD (a 1mV input, 1kHz, 30% abnormal conditions) 0.5% or less
Selection degree characteristic (±10kHz) 30dB
Image ratio 70dB
IF disturbance ratio 60dB
10kHz whistle filter -30dB
Output voltage (30% abnormal conditions) 0.6V
<Synthesis>
Output load impedance Fixed output terminal: 200ohms
Variable output terminal: 2.5kohm
FM antenna input impedance Balance: 300ohms
Unbalance: 75ohms
Meter Three pieces
Signal strength meter
Center tuning
Multipass meter
The variable condenser used FM: Frequency straight line type precision 5 continuous
AM: Precision triple
The semiconductor used FET: Seven pieces
Transistor: 45 pieces
IC: Nine pieces
Diode: 43 pieces
Power source 100V/117V/220V/240V, 50Hz/60Hz
Power consumption 26W
Dimensions Width 445x height 152x depth of 355mm
Weight 14kg