A story of a uncle that built a transmitter that would alter a persons thoughts and make them subject to sexual acts. He refined it on his own sister as well as his neighbor and her daughter. The series is really long as I would like to finish it. Thank you
I did an Advanced Search for the word "transmitter" in the description and found only one story — "Neuro Submission Transmitter" by SamSlam at: https://storiesonline.net/s/63182/neuro-submission-transmitter
It's about a boy who finds his dead uncle's mind controlling transmitter. It is long at over 242,000 words.