Buffered video amplifier is used wherever the use of video player to the receiver / monitor TV with a long cable may cause a drop in signal amplitude and as a consequence, the deterioration in image quality. The amplifier can also be used to connect multiple receivers to one player or VCR.
In any case, it prevents deterioration of picture quality as eating out edstvie greater load the player, or loss of signal power in the cable. This is a simple linear amplifier with low noise level with a broad band transfer (min 20 MHz) and increased ~ 6 dB. You can connect to any source of stabilized voltage 12-15 (in special cases even from the power supply VCR). Current consumption of a small, 20 mA at 12 V.
The scheme works only when using the compounds of “AV” where video and audio signals are sent separately. Not suitable for joints «HF» antenna cable. Make sure to include the video amplifier in the line of the video, while leaving the audio connection. It is possible to use two amplifiers, one of which will be designed for the line “video” other “audio.”
Parts list :
T1, TK, VS547, 548
T2, VS557, 558
C1-C4 100mkFh16V
C5 47 nF
R1, R9-R11 75 0 m
18 k0m R2
R3 5,6 kOhm
R4 1k
R5 270 0m
R6 330 ohm
R7 200 ohms
R8 510 ohms
