NEW KEYUP TOY

Back in 1987, I designed and built a keyup toy for my base and mobile. When the radios were keyed, the toy would run a frequency sweep starting at 200hz and ending at 4000hz. the sweep time was 1 second. To hear what the toy sounds like, go to to this site,

http://onlinetonegenerator.com/frequency-sweep-generator.html

and enter the following parameters.
start freq: 200
stop freq: 4000
duration: 1 sec
select square wave, exponential sweep, and uncheck

“Continue playing tone...

NEW KEYUP TOY