Exclusive F3

Commentary

This FM stereo tuner has been completed through numerous experiments and trial listening in order to realize the "beauty of music" which is the original purpose of audio equipment.

It uses lock tuning by APC (automatic phase control) with built-in crystal oscillator to prevent tuning deviation called drift.
In addition, the receiving frequency is in increments of 100 kHz, and the tuned frequency is locked as it is, making tuning easy.

The front-end section consists of a 7-series varicon for FM and dual-gate MOS FETs selected one by one.

It is equipped with IF band switching, and the wide-band uses the 8th LC phase linear filter with excellent distortion.

The measured values for each unit are attached as is.

Model Rating

Type	FM stereo tuner
Circuit system	MOS FET RF2-stage, 7-train varicon APC system フェイズロックト tuning type IF BAND switching ultra-wide band linear detector 19 kHz canceller circuit PLL + Double NFB Method MPX
Practical sensitivity	mono: 4 μ V (S/N 50 dB) 2.2 μ V (IHF) Stereo : 45 μ V (S/N 50 dB)
Signal-to-noise ratio	wide: 80dB(mono) 75dB(stereo) narrow: 80dB(mono) 75dB(stereo)
Harmonic distortion factor	100Hz 1kHz 10kHz wide mono: 0.08% 0.08% 0.08% stereo: 0.1% 0.1% 0.1% narrow mono: 0.1% 0.1% 0.1% stereo: 0.3% 0.3% 0.5%
Capture ratio	wide:1.0dB narrow:2.0dB
Capture ratio	wide: 12dB(300kHz) 30dB(400kHz) narrow: 12dB(200kHz) 65dB(300kHz)
Separation	wide: 50dB(1kHz) 40 dB (50 Hz to 10 kHz) narrow: 40dB(1kHz) 35 dB (50 Hz to 10 kHz)
AM suppression ratio	wide:60dB narrow:60dB
Carrier leak suppression ratio	wide:70dB narrow:50dB
Frequency characteristic	20 Hz ~ 10 kHz + 0 -0.2 dB 20 Hz ~ 15 kHz + 0 -0.5 dB
Image interference ratio	120 dB or more
IF interference ratio	120 dB or more
Spurious interference ratio	120 dB or more
Muting action level	5 μ V ~ 1.6 mv Variable
Antenna	300 Ω Balanced Type 75 Ω Unbalanced Type
Output Level / Impedance	Fixed : 650mV/3k Ω Variable : 70 mv ~ 2V/5k Ω 4 ch MPX : 400mV/1k Ω
Semiconductor used	Transistor : 71 FET : 10 IC : 20 Diode, etc. : 57
Power supply voltage	100 VAC, 50Hz/60Hz
Rated power consumption	25W
AC outlet	Power switch not linked : 1 system
External dimensions	Width 468x Height 206x Depth 389 mm
Weight	16.6kg