Ignition noise is not the only way a generator can interfere with radio
reception.

A Honda "inverter" generator was used at this year's Field Day, but it
caused a broad-band noise on the HF bands. Locating the generator as
far as possible from antennas helped.

An inverter generator produces 3-phase AC power, rectifies it and drives
a DC-to-AC inverter that produces 60 Hz power. Result is a
lighter-weight generator, and greater efficiency can be achieved by
reducing engine speed when less power is used. Honda's also have
extremely low acoustic noise levels.

A call from the Honda dealer to Honda Technical Support received a reply
that you have to use a LONG extension cord because inverters generate
radio interference! I have since used a portable AM/Short-wave radio to
check the Honda generator as well as one from Yamaha. Both wiped-out
reception up to the 18 MHz range of the radio, when the radio was within
several feet of the generator.

Does anyone have experience cleaning-up the interference from the
inverter in one of these generators?

Fred
K4DII