I notice that there has been some discussion about the GB4000 and the Doug Coil in this thread. For the past several years, the GB4000 and SR-4 Amp combo have been the most widely used GB4000 product for people who want to explore frequencies for lyme.
Within the pas month, we have released the M.O.P.A. (Master Oscillator Power Amplifier) as a new attachement to the GB4000. The MOPA Amplifier can drive a plasma tube with up to 60watts of output power.
The MOPA operates in the 1.1Mhz to 1.9Mhz range and uses a High Voltage, Low Current signal to drive the plasma tube, which is how Dr. Rife did his pioneerning work.