RFIVB4

The RFIVB4 is a kind of integrated television demodulator assembly designed for use with VTSS-series tuners. The device replaces the earlier RIFU0570 and provides the same functionality in all respects. The input is a standard PAL-1 or similar 6.0 MHz intercarrier frequency, 39.5 MHz inverted television IF spectrum, as reference to the video frequency. The outputs are demodulated vide (AM) and audio (FM), an AFT signal to indicate the need for tuning correction, and an AGC control line for feedback to the tuner. The device operates from a +9 V source.

There are some features of RFIVB4 as follows: (1)receiving standard: United Kingdom (PAL I); (2)receiving system: intercarrier sound; (3)intermediate frequency: picture: 39.5 MHz, sound: 33.5 MHz; (4)norminal input impedance: 75 unbalanced type; (5)terminal output voltage: RF: 6.5 V (6.5 to 0 V); AFT: 4.5 V (1 to 8 V); (6)operating voltage: B voltage: 9 V±10%, AFT mute: ON=3 to 15 V; (7)consumed current: 100 mA max; (8)output terminal load condition: video: high-impedance load and audio: high-impedance load; (9)temperature: storage: -40 to 75, operating: -10 to 60.

The following is about the electrical characteristics of RFIVB4: (1)differential gain: 12% typ and 20% max when stair step; (2)differential phase; 10°typ and 20° max when stair step; (3)picture output S/N ratio: 54 dB typ and 47 dB min when weight filter ON, white level 50%, HP 1 kHz, LP Thru; (4)sync. shrinking V.S ratio: 1.0% typ and 1.0±5.0% max when 100% white; (5)picture frequency characteristics 100 kHz to 4 MHz: -4 dB min, -3 dB typ and 1 dB max when multi-burst, 0.1 MHz standard 4 MHz/0.1 MHz; (6)SIN2T pulse amplitude error: -145 typ, -25% min and 0% max when 2T nad bar signal; (7)chroma amplitude error: 30% typ, 0% min and 50% max when SIN2 signal; (8)chroma phase C/L delay: +220 ns typ and +220±90 ns max; (9)sound buzz: 30 mVp-p typ and 100 mVp-p max when multi-burst, 87.55 mod, fp/fs: -25 dB.