The previous answers are dead on.
You may see an increase on your watt meter. But that increase could be in another band
not 11 meters. Hams in my opinion. After 6/10s of a century being on earth. Even Hams
who were 11meter mud ducks at one time. Loath CBers running DIRTY linear Amps.
You may be looking at the amount of Dreaded I.M.D. your box is putting out. This
power showing on your
meter can be interfereing with legal licensed Amateur bands. Fire, Police buisiness,
Airport communications verbatum. Shoosh. Eventually. I'll get a software spectrum
analyser. Pricy. You need to get an LCR meter. Wind your own tank coils.
Not perfect. I go to a free band channel above 40. Check with an acquantance
that his S meter is rising. To try to ensure thw Watts I see on the meter are actually
on that frequency.
You do not have enouph iron in that box to push 400 bananas for any length of time
on AM. ALL the Sweep tube Boxes were desighned For full output on SSB.
On AM they get run on LOW POWER.
Google is your friend. Start with the basics. READ Learn. With 2X driving 4 700v or 800v
at the plate. 400W is possible. NOT RECOMENDED.
Have fun..................High Voltage Kills. Don't shock youself !