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[AMPS] Receiver performance

To: <amps@contesting.com>
Subject: [AMPS] Receiver performance
From: W8JI@contesting.com (Tom Rauch)
Date: Mon, 13 Mar 2000 11:22:10 -0500
> Richy says:
> 
> >I am always afraid that DSP will be used to make mediocre rigs better and
> >not enhance the great rigs. 
> 
> Somehow, Richy, I rather figure that you are by no means alone with that
> fear! Me too.

DSP systems will make the mediocre rigs worse, not better. 

At present price levels, it is impossible to get a quality low-noise 
high dynamic range A/D converter that is fast enough to do any 
good processing for anywhere near the price of a good crystal filter.

Manufacturers are trying to replace crystal filters with digital filters, 
and everyone is transfixed on the AGC loop and skirts...but without 
several hundred dollar A/D converters and very powerful DSP 
systems they won't come close to the performance of a standard 
$50 manufacturer cost filter.

My FT1000 has four filter passbands, and I use two of them 95% of 
the time. I care less about having 50 selectable bandwidths, what I 
want is a clean transmitter and a receiver that can crawl right up 
against a 50 over nine signal and dig out an S3 signal.

Try that with a DSP IF filter, either inside or outside the AGC loop.
  


73, Tom W8JI
w8ji@contesting.com

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