Build a frequency cutout for headphones?

[willy]

I've got a little problem here. Picked up a Goldstrike and it has a 2 tone audio system with no way to disable the low tone. This gets rather irritating and I wonder if anyone knows how to make a cheap and simple filter that would only enable the high tone to be heard in the headphones (something like a crossover)? The low freq. is 500Hz and the high is 1 KHz. ...Willy.

[Carl-NC]

Most likely the tones are produced by square waves, so it is not so simple to filter them. It would be far easier to modify the circuit and disable the low tone.

- Carl

[willy]

That might be tough. Willy don't fool around with IC's and surface mount stuff. Also, wouldn't want to void the lifetime warranty on a brand new detector. Might just have to develop a 'tin ear'. Thanks though..Willy.

[Carl-NC]

OK, didn't realize it was new. I agree, don't void the warranty. Write Fisher & ask them if a factory mod is possible.

Now that I think of it, I'll bet the tones are generated from a microcontroller, which would require custom programming.

- Carl