QRP (reduced/minimal power) intrigues because of the minimalistic nature over very lower power operations, the high distance-ot-power results that can be achieved, and the pure satisfaction of making a contact with so little power. QRP gear is natural travel gear, with a whole station potentially much lighter than the laptop I am typing at!
High power QRO is the alter-ego side of things – the long distance “reach out and ring the bell” sort of operations that puts lots of pure energy into the game. Long haul QSOs simply not possible for most 100w amateur operations, much less any QRP operations become a possibility that can be accomplished with some added power.
As I’ve focused on making my stations “hear well” as the first goal, adding a bit of power brings the transmit side up to the receive’s abilities.
Both QRP and QRO greatly benefit from solid station design. A wasteful SWR make reduce a QRO station’s effective power but the raw “umph” usually remains. In a QRP situation the lower 5, 2 or lower wattage attenuated by a high SWR may leave too little effective power being radiated to complete a QSO.
QRO high power does require substantively uprated components and feedlines. I have a sample piece of generic 50 ohm coax designed for perhaps 200 watt use, that fried from the inside out when the feedline was lit by an Alpha 87a pushing 1.5KW into the 300 feet of line. The QRO power simply cooked the dielectric insulation right out of the coax!
QRO also is unforgiving from safety and RFI in the shack effects. Unlike QRP, which is done wrong or done sloppy, QRO will hurt you – possibly pretty bad – if you don’t follow sound engineering & operating practices.
QRO also breaks the bank pretty quickly – tuners are often 5 to 10 times more expensive than common units, high power coax costs more, the antennas to take QRO power cost much more than simple QRP gear – and then the Amplifier. Perhaps a used vintage Amp for some hundreds of dollars (which can quickly become a non-bargin if it needs tubes or repairs) to a $9,000 contest grade Amp from one of the best makers.
QRP has some costs too – usually the log book takes a long time to fill compared to QRP, so your QSO/Hour operating is likely to be much much less doing QRP operations vs QRO operations. The gear often lacks all the receive enhancements of fine grade QRO or normal power gear – though some of the SDR QRP gear being developed look to change this.
Both are fun and that alone makes them worth my dual effort!