Re: LF: A conumdrum for the weekend - Image Can celling Mixer.

["Alexander S. Yurkov" <fitec@omskcity.com>]

Hi, Group.

On Fri, 25 Apr 2003, Rik Strobbe wrote:

> At the upper leg : SIN(A) * COS(B) = SIN(A+B) + SIN(A-B) (ignoring the 
> divide by 2)
> after the 90 degrees phase shift at the output = COS(A+B) + COS(A-B)
>
> At the lower leg : SIN(A)*SIN(B) = COS(A-B) - COS(A+B)
>
> Adding : COS(A+B) + COS(A-B) + COS(A-B) - COS(A+B) = 2*COS(A-B)
> Subtracting : COS(A+B) + COS(A-B) - COS(A-B) + COS(A+B) = 2*COS(A+B)
>
> So that way theory seems OK.
And it is pointly the same way to depress undesired product wich was
used many years ago for SSB forming by a phase method. This
method was widely used in 50-th.

73 de RA9MB/Alex
http://www.qsl.net/ra9mb