On Mar 22, 2013, at 1:31 PM, Joe Subich, W4TV wrote:
> Similarly, even ARRL (most specifically W3IZ's review in the current
> issue of QST) do not make the slightest mention of signal purity issues
> like the absolutely horrible transmit phase noise spectrum of the new
> FT-3000.
As bad as the FT-dx3000, its transmit phase noise (about -100 dBc at a 1 kHz
offset) is still nowhere close to the interference from an (continuous phase)
FSK signal, whose keying sidebands are in the region of -60 dBc at the same 1
kHz offset from one of the FSK tones.
You might be confusing the transmit phase noise with the poor reciprocal mixing
(-82 dBc at 2 kHz offset) in the FT-dx3000. The latter only affects the owner,
not the other occupants of the band. But even that number is still dominated
by FSK keyclicks from a signal that is 2 kHz offset away (although not by much).
One way to look at it is that if you receive with an FT-dx3000, you probably
won't be able to tell if the other people are filtering their RTTY signals :-).
73
Chen, W7AY
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