Why limit yourself to 5W when a full licence lets you use 400W?
QRP is the 'Q' code for operating with low power. The definition varies depending on the
operation mode and what people prefer. Typically, QRP is 5W or less for CW and digital modes
while it is 10W or less for SSB.
Anyone can make a contact with 400W and any old antenna. It is like using a sledgehammer
to hit a nail. QRP forces you to think about the whole system and ensure you are not loosing
any of your precious RF power to mismatched impedances or other traps. It makes you look at
atmospheric conditions to see whether you have a chance today. QRP can also make your life
easier. Low power means smaller diameter cables and lighter equipment. There is no need for
a heavy amplifier or for heavy heat sinks either. Your neighbours are less likely to suffer
from interfence if you use low power as well. Happy neighbours means less hassle when you
finally get that dream mast set up. Another advantage is the reduced keep out area around
the antenna required for meeting EIRP limits.
There are issues with QRP. It can be frustrating when you are not able to make those
contacts regardless of your skills. Yet, that can also be a positive as it makes getting
that elusive DX contact far more satisfying. There is no shame in boosting power on those
days where 5W just is not cutting it. Many QRP operators use a QRP rig attached to an
amplifier for those sorts of days.
In the end, it is about trying to use the power necessary to make the desired contact. It
does not matter if you want to use higher power or not. Just so long as you play nicely and
use what you need instead of swamping the spectrum for everyone else. We all need to play
nice so everyone can enjoy the hobby.