I’ve done it several years, both by myself in the field,
at home as 1E, and with a club.
Location matters: I’ve mostly operated Field Day from
the West Coast, where our average contact distances
are generally over 1000 miles (and sometimes 2000
miles on 15m). In the Eastern US, conditions will
be different.
I’m not a serious contester, and on CW my relaxed
hunt-and-pounce technique is more of a limitation
than output power. I generally figure around 200
contacts in 8-12 hours of operating, and when the
club switched to high power I only got 300.
Phone is a different story, however. The club
switched to 100W because QRP was too
frustrating for everyone else.
First, make sure your rig is well adjusted, and
you are getting full output power. An
effective speech processor, properly adjusted,
helps a lot. Having a PEP wattmeter available
will help to train operators how to get the
most out of their limited power. Some rigs
have muddled audio that tends to fade into
the background din.
Also, check your rigs beforehand for phase
noise and other issues. My K2 turned out
to radiate phase noise that the other stations
could hear on other bands when we were
all in the same building, but it wasn’t an
issue when I moved the CW station 100’
away. (That’s on my list of things to fix.)
You might want to consider using a standard
transceiver turned down to 5W if it provides
better filtering, speech processing, and other
features you are used to. They will draw
more current than many QRP rigs, however,
which may be an issue if you are using batteries.
On CW I’ve done well with dipoles or an
80m horizontal loop. We put the big antennas
on the phone stations as they need all the
help they can get. Often this is a TA-33jr
at 28’ to 32’, but various wire beams are
possibilities: the last two times we used a
5-element delta loop on 20m, but that is
most effective when most of the stations
are in one general direction. Next time
we probably would add another antenna
for the shorter paths off the sides.
Keep an eye on propagation forecasts,
and an ear on the higher bands like 15m.
Often you can catch an opening and rack
up some contacts before QRM gets heavy.