On 7/17/2016 11:08 PM, Phil Allison wrote:
JC wrote:


So........ How can I reproduce some of the cal signals, for example JIS,
1%, 4Hz modulation at 1vrms?

JIS is 3KHz sine, so no problem, but how to add the 4Hz modulation? FM
obviously, (AM would be easy), but how? Can't be a 4Hz sweep on 3Khz,
can't be a 4Hz burst? Superimposed 4Hz on 3Khz? How to quantify 1%?


** 1% is the frequency deviation, 4Hz is the rate.

So +/- 30Hz deviation four times a second.

( The ear is most sensitive to a 4Hz rate)


I have a wide range of hardware and software signal gens available but
no idea how to mimic this accurately.


** Some function generators have an external modulation input.

Set the generator to 3kHz and use a small DC input to get 3030 Hz.

A 4Hz sine wave with the same peak value is then required.



... Phil


thanks Phil, I'll try it.