The thrust of my post was marketing to the great majority of ham radio operators who, in all likelihood, would see very little added economic value in those four points. Just how much extra do you think that average ham would be willing to pay for those four benefits.
You're absolutely right about strapping on such an amplifier. Works great in the audio amplifier world. Not so much in the RF world. Wrong, he is pitching for investment or cash flow, depending on how you want to look at it, by trying to sell units for "beta testing". I was trying to look at the market viability of the proposed product in today's ham radio environment. I didn't see much of a future for it. You may arrive at a different conclusion. By the way, I am a home brewer but that has nothing to do with it unless you're suggesting the Polar Explorer will only appeal to home brewer and experimenter types, which further limits his market.
If you don’t like it, fine. But nobody asked you to do half assed market analysis for him. The Polar Explorer is technically really interesting idea, something truly new in HF transmitters in along time! I wanna hear more about it and see it become successful.
Re: 5. To borrow from your choice of language, that's a ridiculous "half assed" statement. The 600W AL-811's specs are 120 Vac at 8 amps max. You certainly don't need to update old house wiring for that. Let us know when you find out the actual specs for the Polar Explorer. AB6RF said,"If you don’t like it, fine. But nobody asked you to do half assed market analysis for him." It's not that I don't like it, he asked for input and I provided it. You're right it is a technically interesting idea and it has gained some traction in the audio amplifier world. Here are some abstracts relating to the RF applications. Email me if you would like the full articles. https://ieeexplore.ieee.org/document/5516001 https://www.researchgate.net/public...wer_amplifiers_with_RF_Pulse-Width_Modulation Here's a link to a little history and a good explanation in lay terms: http://education.lenardaudio.com/en/12_amps_6.html
Four pages later of this thread and we still don't know how much measured power is required to make those 500 watts of output. At least I now know how my dentist felt when pulling a recalcitrant, impacted molar... It's times like this when I really appreciate being a devout QRPer.
For the P3, according to their website, 0.2% accuracy: http://www.p3international.com/products/p4400.html
@K1KP - how about a status update please? Is the project still in "development" or has it been abandoned?