this type of mistakes makes learners confused, so I had to double check on other sources to get the correct formula. Which add more doubts in the correctness of the learning material. Professor, please make a correction in order to watchers relay on information
It would be great to see a practical Homodyne receiver like the one described in the September 1973 issue of Wireless World, Page 416 but using components that are easily obtainable (perhaps an NE602)
@@professorricketts Please see rhodamine.eu/~richard/Homodyne/Homodyne.html which contains links to the extracted article as well as the entire September 1973 issue. I built it many years ago though I substituted two mechanically ganged variable capacitors in place of the ganged inductors.
@@badreddinegacem Do you mean w=0 ? w which is read as omega is the angular frequency [ w = 2 π f ] and w = 0 signifies DC. when the signal is mixed with its carrier you get the sum and the difference frequencies. The difference frequency is zero. On either side of w = 0 you have the lower and upper sidebands See the maths at t=22s (it has a typo mentioned in the comments) - this is just the identity Cos(x).Cos(y) = 0.5 [ Cos (x-y) + Cos(x+y)] which is derived from Cos (x+y) = Cos (x) Cos(y) - Sin(x)Sin(y) Cos (x-y) = Cos (x) Cos(y) + Sin(x)Sin(y) Leading to Cos(x+y) + Cos (x-y) = 2 Cos(x).Cos(y) I hope that helps and answers the question you had in mind.
wow this course is soo well made. Splendid. Thank you very much Sir!
On slide number 4, at time 0:22, x(t) X s(t) should have one term cos(win+wL0). Please correct the error
Very obvious, yes. :D
@Professor Ricketts: You can simply add an annotation in the RUclips editor.
this type of mistakes makes learners confused, so I had to double check on other sources to get the correct formula. Which add more doubts in the correctness of the learning material. Professor, please make a correction in order to watchers relay on information
It would be great to see a practical Homodyne receiver like the one described in the September 1973 issue of Wireless World, Page 416 but using components that are easily obtainable (perhaps an NE602)
Send me a link to that article. I couldn't find it. Or the name of the article that is on p. 416
@@professorricketts Please see rhodamine.eu/~richard/Homodyne/Homodyne.html which contains links to the extracted article as well as the entire September 1973 issue.
I built it many years ago though I substituted two mechanically ganged variable capacitors in place of the ganged inductors.
1:42 Dude, can you help here? in this timestamp?
The spectrum figure, it is not clear to me, what is w0 at right? What does it signify?
@@badreddinegacem Do you mean w=0 ?
w which is read as omega is the angular frequency [ w = 2 π f ] and w = 0 signifies DC.
when the signal is mixed with its carrier you get the sum and the difference frequencies. The difference frequency is zero. On either side of w = 0 you have the lower and upper sidebands
See the maths at t=22s (it has a typo mentioned in the comments) - this is just the identity
Cos(x).Cos(y) = 0.5 [ Cos (x-y) + Cos(x+y)] which is derived from
Cos (x+y) = Cos (x) Cos(y) - Sin(x)Sin(y)
Cos (x-y) = Cos (x) Cos(y) + Sin(x)Sin(y) Leading to
Cos(x+y) + Cos (x-y) = 2 Cos(x).Cos(y)
I hope that helps and answers the question you had in mind.
than you