TRIO AFX-31

Commentary

FM/AM tuner pursuing the lowest distortion rate in its class.

The front end consists of a 3-row varicon and a low-noise FET.

The IF section uses 5-stage IF amplification and 3-stage limiter circuits.

Anti-interference measures are taken to improve the IF interference ratio, cross-modulation, two signal selectivity, etc.

It is equipped with an electronic FM mono-stereo automatic switching function which automatically switches to stereo broadcast transmission when receiving stereo.

A high-sensitivity bar antenna is used for the AM tuner.
In addition, a dedicated AM circuit is adopted.

Model Rating

Type	AM/FM stereo tuner
Tuner Section
Receiving frequency	FM : 76 MHz to 90 MHz AM : 520 kHz to 1610 kHz
Sensitivity (IHF)	FM : 3 μ V/84MHz AM : 30 μ V/1,000 kHz 300 μ V/1,000 Hz (bar antenna)
Image ratio	FM : 50 dB or more (84 MHz) AM : 40 dB or more (1,000 kHz)
Frequency characteristic	FM : 20 Hz ~ 15 kHz + 0 -2dB
Signal-to-noise ratio	FM : 60 dB or more (100% modulation, 100 μ V input) AM : 45 dB or more (30% modulation, 1 μ V Input)
IF interference ratio	60 dB or more
Cross-modulation	70 dB or more
Two signal selectivity	35 dB or more
Capture ratio	4 dB or less
Distortion factor	Not more than 0.8%
Frequency drift	Not more than 0.02%
<FM Multi Section>
Separation	30 dB or More (400 Hz)
Distortion factor	0.9% or less
Carrier leak	-45dB or less
<General>
FM antenna impedance	FM : 300 Ω Balanced Type, 75 Ω Unbalanced Type
Output voltage	FM : 1 V (400 Hz, 100% modulation) AM : 0.4 v (400 Hz, 30% modulation)
Output impedance	200 Ω
Accessory circuit	FM mono-stereo automatic switching device MPX Noise Filter Low-impedance output circuit FM stereo display lamp AM ferrite antenna SCA Filters
Semiconductor used	Transistor : 17 FET : 1 Diode : 26 Units
Pwer	100 VAC / 110 V, 50Hz/60Hz
Power consumption	15W
External dimensions	Width 260x Height 105x Depth 237 mm
Weight	3.9kg