[BC] Occupied Bandwidth measurements...

[R A Meuser]

This is quite true and is a great way to calibrate a mod monitor  :-) . 
Actually I use the NAB test CD that has precise bessel null tones and 
play out with a portable CD player. This will become an IPOD source the 
next time I need to do it.

As for measuring with program material, it is pretty simple. Peak store 
the spectrum and look for nothing being greater than -25 DB at ± 120 
kilohertz. It IS possible under some conditions to exceed this mask if 
just a mod monitor is used as a measuring device on the other hand a 
station set up with this method could read high on a number of mod 
monitors. That is why mod monitor reads are not always the best tool. 
They are a great help in reading a wide range of other information, though.



Phil Alexander wrote:

> 
> If you use a spectrum analyzer AND an audio oscillator I would agree
> that is the most accurate way (Bessel zero) but using the spec. an.
> alone is questionable unless you have a good one and can look at the
> narrow slice between 75-100kHz above and below carrier then it is a
> matter of both vision and interpretation.
> 
> Of course we did Bessel zero calibrations "back in the day" using only
> an oscillator and a modulation monitor. In fact, this was the method
> recommended by GE for their early FM gear.