[TowerTalk] Active phased arrays.

[Tom Rauch]

> then the DSP can buy you a whole lot.  I think it's safe
to say that on low
> bands, the dominant noise source is not receiver noise,
but comes from
> "outside", and the interference and signal are hardly flat
and stationary,
> so there's great potential for DSP.

Not at my QTH (or at many others).

Noise floor here is white noise that is the result of random
combinations of countless distant noise sources that
propagates in from sources as far as many thousands of miles
away. There are so many random distant sources it is
indistinguishable from smooth hissing "receiver noise".

Desired signals also vary in phase, level, and direction
over very short periods of time. I can't even combine two
antennas 1000 feet apart on 160 or 500 ft apart on 80.

I'm not disagreeing that adaptive noise canceling receiver
systems could be useful in an environment with dominant
local noise sources, I just think the concept of adaptive
phasing isn't the great advantage we might think.

Heck, I'm still waiting for a DSP radio that outperforms a
conventional radio.

73 Tom