NEW: Dr Hulda Clark Digital Zapper CAN NOT do Rife
After checking their specifications thoroughly, it is obvious that they can not do real Rife frequencies.
Their Spec: Frequency Range: 0000.01Khz - 0999.99Khz (≈ 1MHz)
0000.01Khz equals 10 Hz.
Rife requires a resolution of 1 Hz for most frequencies and it also must be accurate to 1 Hz. If you want to sellect 666 Hz, the closest that they can get is 670 Hz which is not acceptable for Rife, no matter how fancy they make it.
This means that they can not do but only a few Rife Frequencies and even then, with a resolution of 10 Hz, the accuracy can not be very good. Even with a +/- 1 digit error, a selection of 670 Hz could be 680 Hz or 660 Hz and I doubt that they are even that accurate.
ParaZapper MY is accurate to +/- 0.1 Hz on many frequencies and the worst is -2.5 Hz.
ParaZapper MY is much less expensive than their cheapest so you do not get the digital display and frequency selection keys but you get real accuracy which is far more important.