ultra sonic Radar HELP!!!

hellow friends i am working on a ultra sonic radar detector..

How to build UltraSonic Radar (circuit diagram)

i have read the discussions on it but emm not able to find out the one in which you friends have discussed the errors in this pcb. i would be verry thankful if any can send me that link... Thanks in advance...

The kit's schematic and pcb layout have many errors. It is NOT Ultrasonic Radar, it is a motion detector.

C3 is not needed and the opamps should be better than the lousy old 741 types it uses.