I have build a cabel Tv decoder and am tune the channels with a trim cap at 5-57pF but now i wonder if it is possible to build some curcuit with a Ic so I can control four different values of capacistors with a moment switch or something instead to tune in channels with trim cap I can choose the right one of values with switch or button ?? :?:
You can use a digital tuner which is used in new televisions or construct a digital switch to switch between four different values of capacitor or use a Varactor diode to tune your channels using variable voltage (potentiometer) instead of trimmer capacitor.
dont you refer to a channel decoder for scrambled channels, or i didnt understand right?
if i didnt, that means that what kinjal said is correct.
new kind of digital channel tunners are easy to use.
I like your idea " kinjalgp" but I am terrible to construct something of my own, if the is not to much trouble for you I would appreciate your help with some simple or basic Schematic on "digital turner" what do I need for components to build this kind of curcuits?