In answer to all those who don't knowwhat an infinity transmitter is, here is A little history:
A guy by the name Manny Mittleman ra a company called the wireless guitar company located on Liberty St. In NY. Aide from wireless guitars, Manny also built all sorts of electronic wireless bugs". One item, The infinity transmitter was a device that was place inside an unsuspecting persons telephone.
When the phone number of that telephoe was dialed and a certain note was blown into the phone from a hohner, keyof-c, harmonica, the bugged phone did not ring, and what's more, enabled the aller to then hear everything said in he room that the phone was located in. As long as the caller wanted to stay on the phone, all was open to him or he. If the phone was lifted off the hook, the transmitter was disconected ad the "bugged" party received a dial tone as if nothing was wrong with the lne.
Remember, all this was constructed inthe 1960x's when ic's were not as commonplace as they are today. Also ber in mind that during that period in time, even the telephone company was no quite sure on how well or how portable tone decoding was.
Ps. Many government agency's were someof manny's best customers.