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Re: [RTTY] re VE3NEA rtty-modems tests - is MMTTY obsolete?

To: RTTY Reflector <rtty@contesting.com>
Subject: Re: [RTTY] re VE3NEA rtty-modems tests - is MMTTY obsolete?
From: Robert McGwier <rwmcgwier@comcast.net>
Date: Fri, 15 Apr 2005 18:05:27 +0000
List-post: <mailto:rtty@contesting.com>
I own, having paid for,  all of the programs Alex allows out as 
shareware.  He is an amazing
programmer, one of the best in ham radio today.  I say this to preface 
my suggestion that
you say exactly these words to him.  This is the kind of critique he 
would listen to and work
on.

That said, what a great thing we have in ham radio to have two people 
like Alex and Mako-san
programming these fantastic tools for us.

Bob
N4HY


David Hachadorian wrote:

>----- Original Message ----- 
>From: <f6irf@free.fr>
>To: <rtty@contesting.com>
>Sent: Friday, April 15, 2005 7:18 AM
>Subject: [RTTY] re VE3NEA rtty-modems tests - is MMTTY obsolete?
>
>
>  
>
>>>Alex's plots show that TrueTTY is 3 dB more sensitive than MMTTY 
>>>when
>>>presented with an RTTY signal in the simple white noise case.  But
>>>both demodulators require *much* more SNR when faced with the real
>>>world conditions, i.e., "Fig 17."  It is probably because of this
>>>variability why most people don't notice that MMTTY is poorer than
>>>TrueTTY, even though TrueTTY beats MMTTY by an even bigger margin 
>>>for
>>>the selective fade case.
>>>      
>>>
>
>--------------------------
>
>After I saw those plots, I tried TrueTTY, but the manual squelch was a 
>show-stopper for me in real-world usage. If you set the squelch too 
>high, it won't decode weak signals. If you set it too low, there is a 
>continuous stream of garbage characters. If you try to set it right on 
>the hairy edge, changing band conditions and QRM will almost 
>immediately require a different setting. Perhaps TrueTTY performs well 
>in the laboratory, but it didn't work for me on the air.
>
>Dave Hachadorian, K6LL
>Yuma, AZ 
>
>_______________________________________________
>RTTY mailing list
>RTTY@contesting.com
>http://lists.contesting.com/mailman/listinfo/rtty
>
>
>  
>


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