the SWR meters in these radios are calibrated with the power control set to maximum.
those above who said that the meter will read differently when power is lowered are correct.
there is an internal trimmer resistor that gets set for an accurate 2 to 1 SWR reading with the radio connected to a 100 ohm dummy load.
so, if your radio was aligned properly, you should be reading the real SWR of your antenna with the RF power knob turned all the way up, and when you lower the power, the meter is out of calibration and will read lower.
either way, you are dealing with a 1.5 to 1 SWR ratio which to me, means that my antenna is working and has a definite dip to its frequency range. a good thing when it comes to antennas.
remember that a dummy load will read a perfect 1 to 1 SWR over the entire HF spectrum, but won't get your signal out of the room.
the idea when tuning your antenna should not be to do whatever it takes to achieve a perfect 1 to 1 ratio, it should be to 'dip' the antenna and set its lowest achievable SWR within the frequency range of your radio.
BTW the tech that told you that your radio was doing 300 watts should have told you that it needed to be adjusted in order to lower that output the right way.
that 300 watt reading is due to either coils being spread thereby fooling the wattmeter with harmonics and fundamental frequencies being added together (wattmeters are dumb and don't know any better) or the bias on all the mosfets has been set too high and they are not long for this world.
LC