Audio Database

TU-501
Commentary

FM/AM tuner equipped with drum type long scale dial.

The front end is equipped with 4-series frequency linear variable capacitor, one stage RF, and MOS FET.

The IF amplifier uses a linear phase 6-element ceramic filter and LC circuit to achieve an effective selectivity of 78 dB, and a wide-band Quadrature detection circuit and phase correction circuit to reduce stereo distortion.
In addition, high-gain amplification using high-integration ICs and 5-stage limiters reduce the deterioration of sound quality due to interference.

Large level meters are installed on the left and right sides of the front panel and can be used as both signal meters and to measure the tuner output level and power amplifier output.

The newly developed ICHA 1197 is used in the AM tuner section.
The 2-stage AGC improves sensitivity and prevents output fluctuation due to the strength of the electric field. The ceramic filter improves selectivity, interference rejection capability and audio transmission characteristics.

Model Rating
Type FM/AM Tuner
FM Tuner Section
Receiving frequency range 76 MHz to 90 MHz
Intermediate frequency 10.7MHz
Practical sensitivity (IHF) 1.8 μ V
S/N50dB sensitivity Mono : 3.5 μ V
Effective selectivity (IHF) 78dB
Image Interference Ratio (83 mhz) 90dB
IF Interference Ratio (83 MHz) 90dB
Spurious interference ratio (83 MHz) 90dB
AM suppression ratio (IHF) 60dB
Capture ratio 1.2dB
Frequency characteristic 30 Hz ~ 15 kHz + 0 -3dB
50 Hz ~ 10 kHz + 0 -0.6 dB
Carrier leak 65dB
Signal-to-noise ratio mono:75dB
stereo:70dB
Total harmonic distortion rate (1 kHz) Mono : 0.1% (at 100% modulation)
Stereo : 0.15% at 90% modulation
Stereo separation 45dB(1kHz)
40 dB (50 Hz to 10 kHz)
<AM Tuner Section>
Receiving frequency range 525 kHz to 1,605 kHz
Intermediate frequency 455kHz
Practical Sensitivity (S/N 20 db) 300 μ V/m (using attached bar antenna)
20 μ V (External Antenna Terminal Used)
Selectivity (± 10 kHz) 33dB
Image Interference Ratio (1 MHz) 55dB
IF Interference Ratio (1 MHz) 40dB
Signal-to-noise ratio 55 dB (field strength 100mV/m at 30% modulation)
Total harmonic distortion factor 0.4% (at an electric field strength of 10mV/m and 30% modulation)
<Audio Output>
Output Voltage / Impedance 1Vrms/1.5k Ω (at 100% modulation)
Level check voltage 0.5 Vrms (440 Hz, equivalent to 50% modulation)
<level meter>
External audio measurement range + 10, + 20, + 30 dB (0 dB : 0.775 Vrms)
Indication error ± 0.2 dB or Less (1 kHz for each range, near VU scale 0)
Frequency characteristic 20 Hz to 15 kHz ± 0.5 dB or less
<General>
Antenna terminal FM : Screw Type (300 Ω, 75 Ω)
AM : Ferrite Bar Antenna with Threaded External Terminal
Pwer 100 VAC, 50Hz/60Hz
Power consumption 10W
External dimensions Width 430x Height 145.5x Depth 303 mm
Weight 6.6kg