No it is not, although given the huge ammount of wrong info on the net about plasma, i am not surprised.
HF stands for High Frequency, usually they are reffed to as HF/HV as that high frequency comes at a high voltage. Switch mode electeonics are used to produce a high frequency then raised to thausands of volts through a small HF transformer. Very reliable, causes a lot of RF interference.
High Voltage (HV) use high voltage but at mains frequency, derived from a transformer. Simpler and cheaper and highly reliable, but not as reliable as high frequency ones. Cause less interference, but still enough to mess things up if not grounded properly.
Blow back start, uses a means of shrting the electrode to the nozle and removes that short when the air is let through to cause an arc and subsequently start the plasma.
This is the most missinformed and missused naming in plasma industry, last i checked there where only two articles that properly explained it on the net, one writen by Jim Colt of Hypetherm fame.
A simple rule, if it does not have a moving part on the torch, it is NOT a blow back start.
Scratch start has none of the above, so it has to be draged through material to cause sparks and start cutting.
