[BC] Outside source for checking Modulation Levels...

[robertm]

It has gotten easier since back when the NAB released their test CD. All you need is an Ipod to play out the Bessel null tone. It is nice to have a spectrum analyzer (I always have since the 80s) but failing that a narrow band communications receiver with good filters works as well. 


>On Jul 21, 2014, at 7:40 AM, "Dale H. Cook" <feedback at plymouthcolony.net> wrote:

>Bessel function calibration of an FM mod monitor is not difficult, but as with all calibrations of relatively sophisticated instruments it requires appropriate instrumentation, knowledge, and care. Among older monitors I found it easiest to do on the QEI monitors with their internal spectrum analyzer.