On Fri, 29 Jan 1999 16:18:13 -0600 (CST), docdc@ix.netcom.com wrote:
>
>On 01/29/99 00:18:21 you wrote:
>>
>>
>>On Thu, 28 Jan 1999 06:48:22 -0800 (PDT), "Shawn Tayler" wrote:
>><snip>
>>>CW is an excellent weak signal mode, that will get through when nothing else
>>>will.
>>______________________________________________
>>Old wive's tale. Pactor or any of the error-correcting modes will get
>>through when CW will not, and they will do it with 100% perfect copy.
>>Welcome to the '90s, Shawn.
>>
>>73, Bill W7TI
>>
>
>Bill,
>I respectfully disagree with you. I have a YaesuMP1000 with a Kantronics Kam +
>and there is no
>way in hell you can copy pactor when you can't copy CW. Maybe your
>radio-antenna-tnc is better
>than mine ( there are other radios superior to the MP).
>
>Dale
>KC8FAQ
______________________________________________
Well Dale, we will have to respectfully disagree with each other. The
difference in copyabiltiy between CW and Pactor when they are down in
the noise is simple: Pactor knows when an error has been made, CW
doesn't. If you send dit-dit-dit-dah and noise or QRM causes you to
miss a dit and copy it as U instead of V, you have no way of knowing
you got it wrong. Pactor not only knows, it automatically asks for a
repeat and will keep on asking until it gets it right. You can not
fool it - it either gets it perfect or not at all (see note below).
Also, digital signal processing can be done on a Pactor signal which
can actually pull an uncopyable signal out of the noise - one the
human ear literally can not even hear. I'm not saying your KAM can do
that, but it is technically possible given the proper equipment and
software. The times they are a-changin'.
Note: for the purists in the crowd, when I say "perfect", ok, there
is a theoretical chance to get a dual bit flip which could fool
Pactor's error correction, but the odds against your ever seeing that
are about the same as winning the lottery. I wouldn't count on either
one.
73, Bill W7TI
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