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[RTTY] Crystal filter width preferences for RTTY contesting

To: <rtty@contesting.com>
Subject: [RTTY] Crystal filter width preferences for RTTY contesting
From: "Jeff Blaine AC0C" <keepwalking188@yahoo.com>
Date: Tue, 25 Aug 2009 12:23:26 -0500
List-post: <rtty@contesting.com">mailto:rtty@contesting.com>
Gentlemen,

I and a few other guys are working on a project to get a very high quality set 
of crystal filters built for the Yaesu FT2000.  The rig is an otherwise very 
fine unit but the front end is a mess.  This project is an attempt to address 
these short comings.  

And one of the questions that have come up is what the IDEAL width would be for 
the RTTY contester.  So I would like to ask your kind option here.  Anyone can 
reply this - while this is about a specific rig, I would like serious answers 
from serious operators so we can help to ensure the filter guys pick the proper 
width.

So the question (in 2 parts) is like this. 

ASSUMPTIONS:  Assume we are not going to rely on the DSP - and that the width 
of the DSP is wider than the crystal so it's essentially not being used for 
bandwidth limiting.  And assume that the final solution may have 2 filter 
sockets.  Shape factor of the filters is around 1.5:1 and the ringing, while 
present and measurable, is at such low levels as to be inaudible.

Q1. If you only were to get 1 filter, what width would it be?

Q2. If you were to want to fill both filter slots, what widths would these 2 
filters be?

Thanks for your comments!

73/jeff/ac0c
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