| 摘要 |
<p>The receiver, pref. a TV broadcast receiver, has an HF/IF characteristic a symmetrical w.r.t. the carrier frequency, and is used for reception of a vestigial sideband and reduced carrier signal. It comprises a discriminator delivering at its output a control voltage which tunes the oscillator so that the receiver is more accurately tuned to the sender carrier. A further circuit (10-12) responding to noise, interference and sideband signals is connected to the discriminator (1, 3, 8, 9) so that the shift of discriminator voltage due to asymmetry of the HF/IF transmission characteristic, increasing when the carrier disappears, is completely or partly compensated.</p> |
