klemensson posted:
I have two frequencys f1= 30 MHz, f2=13 MHz that I want to get the
difference of (f=f1-f2). Is there a IC or a simple circuit that can
help me with the operation?
You will need, at least, an RF mixer into which you will send the two signals.
When the signals combine (multiply) in the mixer, the output will contain the
sum and difference of the two frequencies as well as other frequencies you may
need to filter. Diodes connected as a balanced mixer works well, but there are
other components that can be used.
You don't say what are the signal sources or what will be the recipient of the
difference signal so not much here can be said about what filtering you may
need. If the output is to a receiver, it might provide all that is needed.
In a google search you should probably look for balanced modulator as well as
balanced mixer. They are essentially the same. You will note that to make an
RF mixer work well, that one frequency (selected as the "carrier" frequency,
should be about ten times higher in level than the "modulating" frequency.
Don
