DENON TU-451
¥ 39,800 (around 1977)
Commentary
FM/AM tuner equipped with drum type long scale dial.
The front end uses a frequency linear 3-row varicon, RF1-stage, and junction FET.
The IF amplifier employs a two stage switching method between the wide (wide band) and narrow (narrow band) of the IF amplifier to achieve both audio transmission characteristics and interference rejection capability.
The wide-band filter consists of a linear-phase two element ceramic filter and an LC filter, enabling reception with excellent sound quality and sound field feeling. The narrow-band filter improves the effective selectivity to enable better separation, and the inter-station noise muting capability is increased to 16 dB to improve the channel selection feeling.
The AM tuner uses an IC to increase sensitivity, and a ceramic filter to improve separation performance and distortion factor.
Model Rating
Type | FM/AM Tuner |
FM Tuner Section | |
Receiving frequency range | 76 MHz to 90 MHz |
Intermediate frequency | 10.7MHz |
Practical sensitivity (IHF) | 1.9 μ V |
S/N50dB sensitivity | Mono : 3.5 μ V |
Effective selectivity (IHF) | wide:30dB narrow:80dB |
Image Interference Ratio (83 mhz) | 60dB |
IF Interference Ratio (83 MHz) | 80dB |
Spurious interference ratio (83 MHz) | 75dB |
AM suppression ratio (IHF) | 60dB |
Capture ratio | wide:1.0dB narrow:1.6dB |
Frequency characteristic | 30 Hz ~ 15 kHz + 0 -2dB |
Carrier leak | 40dB |
Signal-to-noise ratio | mono:75dB stereo:70dB |
Total harmonic distortion rate (1 kHz) | Mono (at 100% modulation) : 0.07% (wide), 0.3% (narrow) Stereo (90% modulation) : 0.09% (wide), 0.5% (narrow) |
Stereo separation | Wide : 50 dB (1 kHz), 45 dB (50 Hz to 10 kHz) Narrow : 40 dB (1 kHz), 35 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 | 0.8% (at an electric field strength of 10mV/m and 30% modulation) |
<Audio Output> | |
Output Voltage / Impedance | 0.7Vrms/2.5k Ω (at 100% modulation) |
Level check voltage | 0.35 Vrms (440 Hz, equivalent to 50% modulation) |
<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 | 8.5W |
External dimensions | Width 430x Height 144.5x Depth 303 mm |
Weight | 6.2kg |