I am a little surprised that no one has brought up the question of measuring
bandwidth. We need to be careful what we ask for - we just might get it.
If the FCC should establish a bandwidth limit of 500 Hz, what exactly does
that mean? Does that mean that all tones AND SIDEBANDS must be within the
500 Hz? Or does it mean that the shift of a signal must be within 500 Hz but
the sidebands can be outside 500 Hz? And if the latter, how many dB down
must they be?
You may recall that the "real" bandwidth of a 170 Hz shift RTTY signal is
approximately 300 Hz because of the sidebands. Given that, what is the real
bandwidth of a mode that claims to occupy 500 Hz, such as Olivia 500/16?
This needs to be settled before the rule is made by the FCC, otherwise chaos
will surely follow.
73, Bill W6WRT
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