[RTTY] Dual Peak Filter question

[Dave AA6YQ]

>>>AA6YQ comments below

-----Original Message-----
From: rtty-bounces at contesting.com [mailto:rtty-bounces at contesting.com]On
Behalf Of Bill, W6WRT
Sent: Saturday, April 09, 2011 11:55 AM
To: rtty at contesting.com
Subject: Re: [RTTY] Dual Peak Filter question


ORIGINAL MESSAGE:

On Sat, 9 Apr 2011 10:44:53 EDT, RLVZ at aol.com wrote:

> can I
>assume then that I'd do better during RTTY contests by  turning my K-3's
dual
>peak filter off" and turning on the MMTTY dual peak  filter?

REPLY:

I operated two contests using the MMTTY AA6YQ FIR512 dual peak filter
and I got the impression it was not copying as well when two or more
signals were present. I asked Dave about it and he agreed - it works
best when only one signal is present, such as in DXing or ragchewing.

>>>The "AA6YQ FIR512" profile uses MMTTY's Bandpass and Notch filters to
approximate a matched filter, with the goal of optimizing weak signal
decoding (and getting to know MMTTY's DSP engine). I used Moe AE4JY's
Pathsim and Alex VE3NEA's "RTTY Compare" to determine the optimal filter
shape.

>>>After discussing this with Mako-san JE3HHT, he added a dedicated dual
peak filter to MMTTY 1.68a that provides this filter shape. Since it's is an
approximation of a matched filter rather than an actual matched filter,
further improvements to MMTTY's weak signal decoding are likely possible.

    73,

         Dave, AA6YQ