In Reply to: Re: high frequency amplifier/generator posted by John Hunter on 01/02/01 at 6:02 PM:
I have found that untrasonic pest repellers work well on deer as long as the repeller is hooked to a motion detector. The noise then startles them. They aren't effective for a long range.
Pricing is around $100 for something that looks like it uses about $3 in parts.
It would be nice to know how to make a cost effective device. I was checking this link to try to find something more cost effective.
If you want the $100 one search on +Ultrasonic +Deer +garden and you'll get a bunch of options.