Hi RX — thanks for the awesome post. I found it while trying to troubleshoot my own Science Fair 130 in 1 Electronic Project Lab from childhood. I successfully built the AM radio station and the Wireless Code Transmitter about a year ago. I just tried rebuilding both tonight to no avail. Would you be willing to help me troubleshoot the kit? I have taken good care of it and have re-wired both projects multiple times with fresh batteries — not sure what the problem is.