The FDA confiscated all of John Cranes research. But it was Royal Rife himself that was working with Crane in the 1950's when they came up with the frequencies for the "pad-type Rife" machine. I think Crane got bitter and disgusted after a while will all the crap they gave him. They started the idea of the "pad-type Rife" machines because they thought it would be more acceptable for the medical community, plus there was a problem using radio waves due to the FCC. The first pad type Rife device was produced in 1958 by John Crane with input from Royal Rife. They gave devices to medical doctors to try and they were doing well. But the FDA raided Cranes office, took EVERYTHING and also went around confiscating the devices from the medical doctors. I'll call out bullshit real fast. The pad-type Rife machines do help when using the "proven" frequencies. People know by word of mouth they can often help. But they need to be dead on accurate. The problem is flat out NO zapper is accurate enough except the ParaZapper MY. That thing is actually a palm sized frequency generator, versus an ordinary zapper.