QuoteThe main advantage of qrp rigs is power drain. Qro rigs in qrp mode drain much more power than pure qrp rigs.
That's true. The 817 realistically draws what on receive, 350ma? Most QRO rigs can be made to draw something in the area of 1 amp if you turn down or off some settings. That's a realistic difference of a solid 500-700ma. Figure 600ma at 12.5 volts and we have 7.5 watts of power savings.
Of course the oft-quoted downside of QRP is it's less reliable ability to be heard. To help overcome this handicap, more efficient modes are used, i.e. CW and digital. The problem with CW is that it kind of requires that the operator learn it. The problem with digital is that it requires a separate computing device, which also draws juice, cutting into your power savings. A laptop is the most convenient platform for working digital but it's also the most power hungry. A smartphone is the least power hungry but kind of inconvenient with it's small interface. A tablet is often chosen as a happy medium. The screen of a tablet is the most power hungry part of it, and unfortunately, outdoor/portable use generally means that the screen brightness has to be turned up to see it in the daylight. An iPad Mini at full screen brightness has been measured to draw about 4.5 watts. This makes your power savings only about 3 watts over a QRO rig that doesn't use the iPad.
So at a battery voltage of about 12.5 volts that comes to an additional 240ma draw on the battery that a QRO rig has over a QRP rig coupled with an iPad Mini. That means that if you want to be able to have 8 hours of receive/monitor time, you'd need a battery that was about 2ah bigger to do so with a QRO rig vs a QRP rig/iPad combo. The difference in size and weight between a 7ah battery and a 9ah battery is pretty minimal and may well be worth it to have the option of going QRO when you need it.
I'm not saying that the 817 is a bad choice. I would certainly own one if I could convince myself that I needed one, and I almost have on a few occasions. It does everything under the sun and coupled with a small power amp can certainly take the place of a shack rig. It's an all around work horse. But to make it a reliable mode of communications, one has to either learn CW or concede that it's power savings over a QRO rig are going to be modest.