Sure Doug, and that is probably the reason why the MeccAlte has a better waveform. Properly engineered, twice the weith of the others and a real AVR to match it.

However, Honda makes a big deal about the "pure" waves on their inverter units, and that makes people think that they really NEED a pure sine. That is the reason I made these tests to start with, to convince people that even the chinese are not as bad as you may think!

The ST heads may be a different story, but I still need to find out myself.
If you want it done properly, do it yourself! It may not be cost efficient, accurate or even reasonable, but still, you have no one else to blame, and for that reason, it is the RIGHT way to do it... 

/Bikerbob

Ok, here comes a long post.

So far I have not hooked up the O-scope to the STC head, but plan to do that within a few days.
I have however tested several other heads over the past years. Some are presented here.
Nice thing to have a PC connected O-scope...

Short version:
You get what you pay for...

Longer version:
Please go ahead and read...

Sure, nothing of this applies to the Listeroids and ST heads, but still... Some sort of reference is always good.
Or as we say in Sweden: "Knowledge is never heavy to carry around with you"....


Note:
-Everything tested is 230V.
-Everything tested is 50 Hz (Europe).
-All the data, all the information and all the pictures are my own.
-No, I do not market this stuff for sales (anymore…).
-The black line in the diagrams (mains) are actual reading from the grid. They are there as reference only.
-I still have to master the "Word to jpg" process. Some of the smaller "ripple" in the diagrams are pixel conversion errors, not actual reading errors. Mainly applies to the "mains" line, since that was not a solid colour to start with. However, look at the pictures, and you will get the picture...   

First, a simple chinese 2-stroke unit:



Something with electronics in it. Looks impressive, but with chinese durability at it's finest...   



Japanese unit with Honda engine. Looks promising, but at this price, forget it! 
Not everything with an inverter in it is good to be sold, especially not if the asking price is 80% of a genuine Honda unit...



First diesel is a Chinese high revving Yanmar clone. Max 1800W. My favorite for field service use. Lightweight and quiet (well, relatively...)



Second diesel is pretty much the same as the first, but 4200W, head with AVR.



Third diesel is a sound-proofed version of the one above. However, 400V unit (phase/phase voltage).




And finally, a proper generator from MeccAlte. I have the specification... Somewhere. Or I will go out in the garage and read off the head.

Water energy meter. Pretty much a common volume meter, but also checking temp in and out.


Heat exchanger.
A car heater element, wrapped in copper.
Works good, since the thermosiphon goes "top" to "botton", and the cooling water "bottom" to "top".
In the picture the exchanger is wrapped in a highly insulating material. A cotton towel...
Note the not-so-permanent fixing to the engine...

Ok, so I have been travelling internationally about 85 days this past year.
Not really a lot of time for my Listeroid...
However, today I took a grip of things and made some long awaited changes.

So far I have:
-10/1 (Volvox, JKSON)
-7,5 kW STC (400V, 3 phase)
-Steel base, concrete filled (approx 300 kg, roughly 600 pound), bolted to two lengths of wooden railroad sleepers (2,4 meters, 8 feet long, weight unknown, heavy...)
-Thermosiphon heat exchanger with thermostat.


A couple of things needs to get sorted:

-Balance! Hey man, this is a jumper. Even considering some type of fleible exhaust tube (metal) is out of the question! Too much movement, also transferred to the subsoil.
Fun part is that there is not really a big difference between a 60 kg (120 pound) base and a 250 kg (500 pound) in terms of engine movement. A lot of energy stored in an engine like this...
I think the main problem is that I have a base that extends in the direction of the crankshaft. Allows for a lot of "forward and aft" movement. Simple thing will be to turn the engine around and see if it makes a change. Have to do that soon, before balancing.
Base is the same as in this picture http://i71.photobucket.com/albums/i140/Listeroid/41e11ab6.jpg (no, that is not me in the picture) but now it is concrete filled.
If nothing else helps, I have to bolt it to a "rock". We have granite coming to the surface next to the garage. Concreta, bah, here we talk MOUNTAIN! Would be fun to try 

-Exhaust heat exchanger. Just have to get a reasonable balanced engine first, otherwise everything will vibrate to pieces in no time at all. 

-Belt transmission. Uses dual 1/2" belts today, on the pulley that was delivered with the engine. Dual groove pulleys can be ok, if both grooves have the same width... Full tension on one belt, the other one not even close to normal tension.. Oh the joys of quality products...

-Intake silencer and air filter. Will probably go for "foam" air filter.

-Exhaust also needs to be worked on. Problem now is that I need a VERY flexible exhaust, given the movement of the engine. Hopefully I can cool the exhaust enough to use high temp rubber hose.


We are down to freezing termperatures here now, so I could not get cooling water to the heat exchanger when I tested that setup today. Just a 10 minute testrun to see that the thermostat opened properly and the termosiphon worked out ok.
I will monitor the energy that I get from the cooling water when the waterhose is no longer frozen...


Plenty of work left before thie Listeroid can be used for any good work.
Want to have it "useful" beginning of April, to heat the swimmingpool, for testing purposes...

The struggle continues...

Well, there is a lot of knowledge ot there.
Here, in writing, just a few things to confirm what others have been writing before. This time, from real experience, real test labs etc... So this time (for a change) i know what I am writing about. 

I work for a company that produces lawn and garden equipment.
I work only with the problems (after-sales and service...), or, in my twisted mind, the fun bits!


This means that I have some real life experiences, not only from one or two engines, but from about 1000 engines over the past 4 years...
We have been modifying B&S 5,5 Hp Intek engines to run on Ethanol for a few years now.
Only problem has been jetting the carb correctly. We ended up fitting an adjustable main jet, and that problem is gone.
The modification is fully our responsibility, since B&S are not willing to support this in any way.
Our risk, our customers, our warranties in other words...

Here in northern Europe, environmental concerns are high, and we always try to look into the future.
Right now, future for us is renewable fuels, spelled Ethanol.
Now, we have our own engines built (far east), ready for Ethanol straight from the factory!

Looking at our specific market, 16% of all new cars sold today is so called "flexi-fuel" cars (pump gas or E85, or any mixes in between).
Reason for this high figure is mainly lower tax, free parking in some cities etc.

Readily availible (+500 filling stations in a small country with a population of 9 million!), and cheaper than normal gas (-30%), the E85 is a success. (85% ethanol, 15% normal unleaded gas).


E85 in modern cars:
My wife is driving a Ford Focus (-02). Reasonably modern, according to my standard.
To run that car on 50% E85 is no problem what so ever. No modification, no changes in MPG. Nothing that I can measure anyway.
This is also the experience from others. Older cars (carb. engines) just need higher fuel pressure to get more fuel (10-20% into the engine.

E85 in small engines:
Ethanol is more corrosive. I have seen float bowl cups perforated, main jests plugged etc. but it is all because of one thing, and one thing only: Storage.
Ethanol will absorb water. Water will corrode just about anything...
Store the carb. DRY during winter storage (over 4 weeks storage time).

Modifications:
Two things needed to make the engine run perfect on E85.
-Raise compression. Normal lawnmower engine is typically around 8,5:1. Shoot for 10:1.

-More fuel. Approx 15-25% (by volume) is typically enough, given that you run E85. 
I know, theoretically you need 46% (by weight) more, but because of density of Ethanol, that equals 36% more by volume to reach lambda=1.
The 15-25% I refer to is however real life experience values, not theoretical. Yes, sometimes it is hard to know if the real world or the map is correct. That is when it is handy to have an engine lab...

Given that the price of E85 is (today) about 30% lower than pump gas, the main reason why people choose to run on Ethanol is because of taxes (on cars) and environmental concerns.
You cannot really save a ton of money running on E85, but it makes you sleep better at night, knowing that at least it is renewable resources...

Note: A modified small engine will not be 100% flexi-fuel, since it will be running very rich on pump-gas.
Change the main jet, and you are however back to pump gas specification again.


Starting:
The starting problem that you all are referring to is mainly because of the low compression. Run higher compression, and most of those problems will go away, since you have almost a "diesel preheating", because of the higher compression.
You also need a good ignition system.
Old B&S systems were typically a little "weak" in the start-up range compared to some of the more modern systems found today.

But honestly, I would not run Ethanol in my snowblower, or any other "critical winter machinery".
On other words, in the winter, no tests with alternative fuels in the car...
Lawnmovers are ideal test animals. Relatively cheap, simple designs and only (mainly...) used in non freezing temperatures.


Emissions, start up
Emissions are mainly unburnt Ethanol. We all know ethanol can be dangerous, especially if you drink it...
No, but seriously, since the E85 contains smaller volumes of nasty (cancerogenus) hydrocarbons, the startup emissions have been found not to be as bad as the startup emissions from gas powered engines.

Ecological?
Well, depends on how you calculate.
Some say you need more energy to produce then you will ever get out of the fuel, some say the opposite.
That is all up to you.

Oil:
Maintain your regular intervals. On a small lawnmower engine, that typically means...never...
Seriously, oil is cheap, engines are not. Your call...


/Bikerbob

aqmxv: Well, if i stick here, I will need help. However, there is a something special about slowspeed diesels.
Do not ask me why, but it is SOMEHTHING!

A degree in human behaviour and psychology anyone?

/Bikerbob

Just look, and listen...
Then find a way of getting one...

http://www.youtube.com/watch?v=n6seReCKRLA

Not a clue to what it is, and where I can look at it, but I do know one thing: I NEED one...

/Bikerbob

Take that 1000 gallons of energy!
You will figure out how to use it one way or the other! Blend/heat/filter/ or use it in the fireplace to start the logs....whatever. Energy = $. About $3000 by todays prices, which is not a bad day's work.

I'll go for that! Grab it, and make use of it, one way or another!

Just have to figure out a way of pumping the stuff... It is sitting in a cold (12 degrees C, about 53F) tank...
Giver says it's like "really slow flowing"...
No, heating the tank is not an option... Or maybe I have to...

Filtering is already identified as being a major task.
On the other hand, there is no such thing as a free lunch...

Starting and stopping on normal diesel (Sulphur free, 0,001% sulphur is STANDARD here in sweden for road vehicles!).
Running the Listeroid on a blend of Diesel, #6 fuel oil, Biodiesel and used engine oil... Probably I need a shed full of tanks, valves, filters and pumps to do it, but hey, it's free... 
No, but seriously, 20-50% of #6 feels like it can be within reason.

Just have to figure out how to pump the stuff...