Yes, thanks, I think what they are really talking about is the deviation of the wave form +/- due to an engine driven unit not running smooth enough to generate a consistent wave form pattern and that is cured electronically by an inverter....my understanding
Which who is talking about what what?
But, um, no.
Syncronous gens produce sine wave. The "purity" of the sine wave is pretty much irrelevant. Look at grid power on a scope and it's dirty as hell. But it's "clean enough" to get the job done. If you look closely enough, there really aren't any "pure" sine waves except under labratory conditions or at recording studios or radio stations where they've installed isolation transformers to get clean power to the equipment.
Variations in the engine rpm results in variations in the rotational speed of the alternator and that results in variations in the
frequency of the AC. To keep a steady 60hz, the alternator has to spin at a steady RPM (at some multiple of 60), so syncronous gens have governors to keep them at a certain rpm. Big diesel gens usually run at 1800 rpm. Old putt-putt Lister diesels might be at 180, 300 or maybe 600. Some Onan RV gens run at 1800, some at 3600. Almost all small portables run at 3600.
The inverter-type gen was not invented as a way to make "clean power". Syncronous-type already makes clean power. It was invented as a way to de-couple the alternating frequency from the rotational speed of the alternator. By taking the AC from the alternator, rectifying it to DC and then running it through an inverter, the gen can now produce a steady 60hz - regardless of the engine/alternator rpm.
Of course, on the face of it, going AC to DC and back to AC is a stupid idea because it's a)inefficient and b)expensive. Which is why inverter-type gens are less efficient, in terms of watt*hours per gallon, than syncronous-type gens, and cost more than double to build.
But...
Since most portable gens rarely, if ever, run at full load, being able to throttle up and down according to load can really stretch out the run time per gallon. Inverter-type gens produce less watts per gallon, but they'll run for more hours per gallon...as long as they aren't fully loaded. Under full load, they run less hours per gallon than a sycronous-type.
And because they can throttle down they are quieter...again, as long as they aren't under full load and screaming along at 5k rpm...
Other than low powered electronic devices, cell, computer, etc. I don't think there is much of a requirement for a consistent wave form, appliances and common tools like a drill will still operate with power fluctuations, may be not as efficiently but the work.
The wave form is almost always consistent, it's the voltage and frequency that tend to wobble around.
Pretty much anything can work off a square wave or modified (stepped) square wave. There are only rarely things that don't. SOME battery chargers, mostly for power tools, are known to be a roll of the dice.
Most electronics don't have any problem with it. Hell, the inverters in APC UPS battery backup units for computer server rooms are modified square wave.
And everything works just fine with the dirty sine wave from the grid (noise is the the problem there).
What often smokes electronics is a drop in voltage (surges are almost never a real problem). If the parts on a circuit board are sized to carry X milliamps, and the voltage goes down, then the amps goes up and now that circuit is carrying way more milliamps than intended. Zzzzt...something gives. Could be a resistor, diode, capacitor...or maybe one of the traces on the board itself.
But that's a voltage problem and unrelated to freq or wave form.
12V will provide reliable and more consistent power, certainly good enough for HAM transceivers, TVs or a micro if it is sensitive to drops or cycling, don't know about micros.
Again, frequency. TVs and microwaves have clocks that work by counting alternations and divide by 60. If the alternating frequency goes off by 10%, then the clock will be off by 10%.
Other than that, they don't have problems with dirty sine waves or varying frequency.
You're more electronically minded than I am, but. like you, I'm not too worried about a perfectly square wave form for over the road use.
Well that's good, because the Wen 1800 is a syncronous-type that produces sine wave, not square wave.
Dunno what inverter you have, but if it's not a sine wave inverter, then it will be a modified square wave inverter. Pretty much no one makes old fashion straight square wave inverters anymore. And modified square waves are not a problem for 99.99% of stuff that runs on 120/240 60hz AC (or the more modern 230v 50hz that the vast majority of the world uses).