Topband: 160m Receivers - the argument for true DSP (long)

[Tom Rauch]

Hi Steve,

I think you missed my points totally.

I'd be the first to encourage people to spend money and effort to hear
better, but they should also be encouraged to spend money wisely.

Rather than argue or voice subjective opinions about "what's reasonable" or
"darned good", it would be nice to see Phil describe why a 40dBm TOI 6-10dB
NF mixer/receiver system is necessary and how and why it would directly
change the ability of a fellow with a typical good receiver like a FT1000MP
in an urban or suburban environment to actually hear better (barring his
present receiver is defective).

Where can we buy a processing system and software that will let unfortunate
city dwellers hear without noise, and who will stand behind that result?
Where can we get one that allows us to use a 40dBm TOI 10dB or better NF
mixer?

Where can I buy software and a DSP system that will allow me to combine TWO
antennas that way, let alone four or more??

I'd be willing to buy the software, if it has a money-back guarantee.

As for matching the bandwidth, I disagree it requires a DSP system. A good
250Hz filter works just fine, and is within a couple dB of anything anyone
could do. Certainly 25Hz BW and normal CW at normal speeds without ringing
is a pipe dream. Bandwidth is set by the rise and fall times, not speed.
With 25Hz BW, I have to have significant rise and fall time (40mS or more)
unless the skirts are useless.

Knowing the cost of very fast reliable A-D convertors with enough bits to
process 100dB dynamic range, I'd like to know how to do that with a $100
sound card. Short of that, what is the actual limit for what we could buy?

73 Tom