[Yaesu] FM Receive on FT-757GX

[Christopher (Chris) W. Boone]

Glen Zook wrote:
> Use of +/- 5 KHz deviation is allowable on those
> portions of the amateur bands above 29.0 MHz which
> allow phone type of operation.  Below 29.0, FM is
> still allowed, but, the deviation cannot exceed +/- 3
> KHz which gives a bandwidth the same as a "normal" AM
> signal.  This is often called NBFM (narrow band
> frequency modulation).  Although many rigs now operate

No, actually the rules allow a Modulation Index of 1 at the highest
freq of modulation, so IF you modulate the xmtr with a 3kHz tone
and set it for 3 kHz dev, you're legal...but with voice, or a
1 kHz tone standard, you'll find thats different...

Also its called SLIVER BAND; has been for decades......
5 kHz dev is NBFM...15 kHz was and is still (though noone uses it)
WideBandFM.....

> below 29.0 MHz have FM as a mode, the vast majority of
> them are set up for +/- 5 KHz deviation and are thus
> illegal to use for FM below 29.0 MHz.  Also, the
> closest that you can actually operate to 29.0 MHz
> using +/- 5 KHz deviation is 29.005 MHz since the
> width of the signal is such that the modulation will
> take it down to 29.000 MHz.  In fact, as a practical
> matter, I would never operate using FM with +/- 5 KHz
> deviation below 29.010 MHz to allow for any additional
> modulation products that might be present.

Very true indeed!!!

Chris
WB5ITT