[time-nuts] Hetrodyning concept

[Taka Kamiya]

I have a question on heterodyining concept.
Say you have f1 and f2.  Say you have f1 <> f2.  Then the product is |f1+f2| and |f1-f2|.  (fundamental is not considered here)
What would happen f1 = f2?  If phase is the same, it will be 2sin(omega t).  (amplitude doubles)  If phase is an odd multiple of pi radian different, result is zero.  (cancels out each other)
What I am trying to do is to first, understand this in case where f1 = f2, and second, mix f1 and f2 and get f3, which is a sum of f1 and f2.  Doubling won't do.
Can someone help me understand this?  I haven't seen discussion of cases where source frequencies are equal anywhere.



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(Mr.) Taka Kamiya
KB4EMF / ex JF2DKG