Independent Power Supply For Local Oscillator
One consequence of the relatively high impedance of power supplies is that leakage from the +B line of the power supply unit can feed back to the local oscillator to modulate the local oscillator frequency. This causes tuning inaccuracies by deflecting the tuned frequency above and below its optimum level. Kenwood engineers solved this
problem by eliminating the source itself — the + B line to the oscillator, giving the local oscillator its own independent power supply. With two power supplies, noise due to leak- age is virtually
High Quality AM Section
In the past, AM sections of FM/AM stereo tuners have tended to be neglected because of the generally inferior quality of AM broadcasts. Now, Kenwood tuners are fully able to reproduce the upgraded AM broadcast quality, with
AM sections that are as carefully designed as FM sections. In the
Sample-And-Hold MPX Circuit
As with the Pulse Count Detector, Kenwood engineers have taken advantage of the exceptional accuracy of digital pro- cessing with the introduction of the
caused by noise or distortion are ignored. This greatly reduces the need for filtering, which vastly improves chan- nel separation, because filtering can obscure important information in the composite signal, interfering with the abili- ty to isolate left and right channel signals. The peak pulses are sampled then held in a capacitor until the next peak ar- rives; thus, the average peak value can be instantly adjusted for precise representation of the original 38 kHz subcarrier. The
Quartz Synthesizer Preset Tuning
Kenwood's
desired station is manually tuned in, and then the preset button is pressed, after which any one of eight station buttons may be pressed. Whenever that station is desired, pressing the station button previously selected will automatically tune the station. This system is fully utilized in the