[TenTec] Argo V and digital modes

[Jim Brown]

On Mon,9/22/2014 4:42 PM, ken.d.brown at hawaiiantel.net wrote:
> If you use what I call "real FSK" there is only one tone being sent at
> any one time. There is no carrier that needs to be suppressed as in AFSK
> to a rig in SSB mode. There is only one tone so there cannot be any
> intermodulation.

But there is a discontinuity that results from switching between the two 
frequencies, which produces transients that will excite intermod. Think 
about it -- even if you manage to switch at a zero crossing, the 
resulting waveforms have two different slopes by virtue of their 
different frequencies.

If you doubt that, look at the spectrum of your "real FSK" in an 
analyzer set for high frequency resolution.

73, Jim K9YC