Does a "Rife" machine produce X-rays?

Simple answer - no.

X-rays are form of extremely high frequency electromagnetic radiation - well above ultra violet light. They contain a very high energy level and it takes a very high energy level to produce them. A normal X-ray tube contains a vacuum and it works by accelerating electrons to very high speeds and smashing them into a heavy metal target. This causes electrons deep in the core of the atom to be knocked out of place which then radiate X-rays to lose the added energy. High voltages are used to accelerate the electrons - typically of the order of 60,000 volts. A typical modern plasma machine will not produce voltages anywhere near this high and so is very unlikely to accelerate electrons up to the necessary speed to produce X-rays. Secondly plasma tubes contain gas. The gas in the tubes also collides with accelerated electrons so that they don't tend to reach the target in a direct path. By the time they do they've lost a substantial proportion of their energy to the gas and so don't have enough enough residual energy to induce X-ray emission in the target. X-rays will not be produced by electron/gas collisions because the gases don't have electron shells deep enough near the nucleus to have the required energy - you need heavy metals like Tungsten for that. Additionally, impacts on tube electrodes energetic enough for X-ray emission will cause tremendous heating of the target - enough to drive the target to white heat and melt in a matter of minutes or less. X-ray tube electrodes are usually specially cooled - often with liquids. The electrodes of a typical plasma tube as used in modern Rife machine designs are just too weak to be able to withstand any sort of sustained X-ray emission.

A normal cathode ray tube as used in a typical colour TV or computer monitor has a vacuum and works by electron impacts, it typically uses voltages around 25,000 volts. So an ordinary colour TV is far more likely to produce X-rays than a typical Rife type plasma tube. It is also worth remembering that we are constantly bombarded by X-rays from space and even from trace amounts of radioactive gases in the atmosphere. All of these are stronger sources of X-ray emission than a Rife tube.

Finally, Rife and John Crane had their machines measured in a standards laboratory for X-ray emission and the results were certified as negative. They were using much higher voltages in their older machines than most modern variants do.

Although in theory, one could get X-rays of the longest wavelength with only 150 volts, in practice one needs at least 12500 volts to get X-rays able to penetrate the envelope of the tube.

X-ray tubes which are used for X-ray fluorescent spectrometry, are working at 5 kV only through Be window, with a 40 Wt consumption only...

Even if Rife Machines do produce a small amount of soft X-ray radiation on the highest harmonics of electro-magnetic oscillations, it doesn't matter, as far as you use them for short treatment only. The natural radiation background is much, much stronger, as it was fairly mentioned above.

And it couldn't be compared anyhow with sledge effect of routine medicine Radio and Chemo treatment...