Here is one example how to make calibration pulses in CoolEdit for calibrating DIY GM counter.
Procedure:
1. Generate -> Tones
Then set values as is show on first part of that picture (for 500 C/M, it is 8.3333 Hz, or 8.3333 * 60 = ~500 C/M).
2. Effects -> Amlitude -> Amplify
Set Peak level to 0 (zero) dB, and click on calculate, it should show 6 dB amplification. Then click 'OK' button.
3. Effects -> Filters -> Quick Filter
Set that filter as is in third part of this picture. After filtering it should look as is shown on last two parts of the picture. Note difference in appearance in 500 and 50000 C/M. This is because that way of producing precise sound for calibration of the GM counter is not the ideal, but it is good enough for our purpose.
I think that it is better to calibrate DIY GM counter to some degree of accuracy in C/M (counts per minute) than guessing.
