Kenwood KT-1000 manual Direct RF Conversion, New Pulse Count Detector IC

Product policy

For over three decades, Kenwood has continually intro- duced innovations in tuner design and engineering. The name Kenwood has thus become universally recognized for excellence in tuner technology, and many satisfied users will testify that for them, the tuner is Kenwood. But there's a whole lot more to tuners than the technology, these days. The average, non-audiophile also wants to be in on the high quality FM and AM broadcast scene, even though the budget is usually rather restricted. For such customers, Kenwood has the answer. At the top of this year's line-up is

the KT-1000 incorporating the latest in tuner technology, but packaged without the frills to attract a wider market. A bit under in terms of features and price range comes the KT- 900, but still offering the superb sound quality expected of Kenwood. Finally, there's the totally new-style KT-800, an automatic computer-guided tuner that combines excellent sound quality with unrivalled ease of operation. Here's a rundown of these three great new tuners, and the sales points and facts to help you sell them.

New Pulse Count Detector IC

Conventional FM detection circuits using an analog method allow a lot of chances for noise or distortion to be intro- duced to the original FM signals. In order to faithfully preserve the original characteristics of the FM signals, Kenwood has developed a new Pulse Count Detector IC, which uses a digital method to detect the FM signals. Fol- lowing is a simplified explanation of how it works.

The wave shapes of the individual FM signals are sampled and the basic wave shape of each are converted into digital equivalents in the form of pulses of equal width and ampli- tude. Since only the basic shape of the signals are con-

verted into digital equivalents, any minor deviations or rip- ples caused by noise or distortion are simply ignored — the result is a digital equivalent of the pure original FM signal, free from distortion or noise and remarkably stable against changes in temperature, humidity and age. When converted back into an analog signal, the signal at output is exactly the same as originally input. Any noise or distortion that might have affected the signal during the detection process has been completely eliminated. This system is utilized in the KT-1000 and KT-900.

Direct RF Conversion

When there are many powerful FM stations and other sources competing for air space, extraneous signals are all too easily picked up by the FM antenna and amplified, introducing a great deal of noise and distortion. To eliminate such interference, Kenwood has developed a Direct RF Conversion technique. This by-passes the RF amplifier stage, sending signals instead directly to the mixer stage,

where the intermodulation products produced by the interference of extraneous signals are attenuated rather than amplified. Either Direct RF Conversion or normal con- version can be selected by a switch, allowing the choice of the method most suitable to the particular reception condi- tions. This system is utilized in the KT-1000.