ELEKTOR FORUMS

I've measured a Frequency of 1.47 MHZ on the course board BNC female socket K11 using my own scope and two different DMM's .

It would appear that you got the program wrong, for the assignment was a frequency of 500 Hz. A faulty buzzer is unlikely to increase the signal frequency.

What should the resistance of the Buzzer coil be, as I am measuring over 6kohm. This is obviously too high and I suspect the coil to be faulty.

Assuming you didn't desolder it then depending on the position of the variable resistor that is mounted over the buzzer as volume control the resistance measured over the buzzer should be between 0 an 10k, so you're ok there.

Check your program. If you're convinced that the program is ok then pull jumper K10 and measure the frequency on BNC K11. If that is 500 Hz then the buzzer may indeed be faulty. If that is something else then program is wrong, or the settings as shown on page 54 and onward have been entered incorrectly.

Page 103 doesn't show that formula at all! It shows this one:

............... 1
f = 0.5 x 1. 10^-3

Can't get that quite right (hence the frequent edits of this post) but if you look at page 103 you'll understand what I mean, so

f = 0.5 x (1/1.10^-3)

which equals 0.5 x 1000 = 500 Hz. So the formula and the calculated frequency of 500 Hz are correct. Perhaps it is better if you don't jump to conclusions too quickly.