[TowerTalk] Re: [DX] Some Thoughts

Gerald Caouette ve6nap@oanet.com
Wed, 29 Oct 1997 23:38:06 -0800


David Robbins wrote:
> 
> some of the low data rate digital methods used to communicate
> with nuclear missile submarines will out perform cw all the time.
> same with the methods used to retrieve data from planetary probes.
> there are also other ultra narrow bandwidth methods that will
> receive signals you could never hear.... and could never be done
> without digital receivers and decoders.

At last some one who is willing to bring digital correlation reccivers 
and transmiters to amateur radio ... Although at each moment in time
these signals consist of very narrow band width signals the need to 
frequency hop or shift to transmit data bits consumes a significant 
amount of spectrum. .The higher th data rates thew more spectrum is 
needed to transmit the data. 

Cw still remains the narrowest single frequency 
mode to transmit information reliably .. ( Human factors not taken into 
account)... The other digital modes that we as amateurs use at present 
remain spectrum hogs  when compared to CW.  


A light read that will give you some insight into these principals is

Modern Signals and Systems 
By 
Huibert Kwakernaak and Raphael Sivan 
ISBN - 0-13-809252-4 

Available at most University Book Stores.

73
de 
ve6nap@oanet.com

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