AC coupling video line

[Jackie]

I want to ac couple a 75ohm video line into the A/V input of a monitor.

What value capacitor should I use to do this?

IF it is an electrolytic, does it have to be a non-polarised one?

Jackie

 

[Brummer]

Consider this:
The input of the monitor will be 75 ohms.
The lowest frequency that you will need to pass will depend on the clamping
circuit inside the monitor. However it is usual to accept the lowest frame
rate as the minimum.
Say 25 Hz in this case.
Now Xc= 1 / (2 x Pi x F x C ) gives
C=1 / (2 x Pi x F x Xc)
= 1/(2 x 3.1415926 x 25 x 75) farads
=85 uF (say 100 uF)
Now electrolytic capacitors require a DC bias so if there is not any then an
unbiased type would be needed.