Chip, I built what I called my bug catcher using nothing more than a fan motor and blade off an oscillating room fan. So it's as quiet as one of those. I built it by making a round sheet cylinder with the fan mounting in the back and a couple of 60 watt light bulbs mounted around the inside of the cylinder out ahead of the fan blade. Then at the back of the cylinder I attached a sheet metal cone that went from the diameter of the cylinder down to about 8 or 10 inch diameter. To that you connect a standard 90 degree heat duct elbow to direct the bugs downward. The fan sucks the bugs into through the cylinder, blows them into the cone and down the elbow into a mesh bag you hang from the elbow. The mesh bag needs to be a fine but very open mesh. I used something similar to the mesh that comes with those mosquito head nets you can buy in sporting goods stores. I got the mesh at a fabric store. I would some times catch the equivalent of about 2/3 of a 5 gallon pail full of bugs in one night.
If you think anyone else may be interested in the bug whacker pictures feel free to post them. They can ask if they want more details such as part numberss and info on how to determine the exact trimmer line length that can be driven by the motor. I'm willing to share the design.

Gotta get back to fishin!