DUB 688 KHz chroma from another VCR at pin 5. The power supply for IC-7 at pin 4 is supplied from
the Video REC/EE 12V line which is powered only in the RECORD or E-E mode so it supplied no
output in any other mode. The selected output IC-7 takes two paths to the chroma record amplifier on
the RA-2 board, and to the PS-10 board.
The 688 KHz output signal from the MD-4 board is supplied to the chroma record amplifier on
the RA-2 board. Pot R1 is a gain control for the chroma record amplifier and is used to set the chroma
record current level.
The transistors Q1, Q3, Q4, and Q5 form the actual chroma record amplifier. Q2 is a muting
switch that is actuated by the blanking interval switcher circuit. When Q2 is turned on the chroma
record signal is muted.