Re: [TenTec] Re: [Ten-Tec] Alas, not for me

[Joe Giacobello <k2xx@swva.net>]

OK, Bob.  I wasn't sure.  I had ordered one of the 4 Khz filters and 
was, obviously, interested.

73, Joe

Bob Henderson wrote:

> Hi Joe
>
> No...the Sherwood data is for the stock FT1kMPs.  So far as I'm aware there
> isn't yet any independent data at 2 kHz for the MPs with the Inrad roofing
> filter.
>
> Bob, 5B4AGN
>
> ----- Original Message ----- 
> From: "Joe Giacobello" <k2xx@swva.net>
> To: <tentec@contesting.com>
> Sent: Friday, September 03, 2004 9:59 PM
> Subject: Re: [TenTec] Re: [Ten-Tec] Alas, not for me
>
>
>  
>
> > Bob, are Sherwood's data for the FT1KMPs with the 4 KHz Inrad roofing
> > filter installed?
> >
> > 73, Joe
> >
> > Bob Henderson wrote:
> >
> >    
> >
> > > ----- Original Message ----- 
> > > From: "John Rippey" <w3uls@3n.net>
> > >
> > >
> > >
> > >      
> > >
> > > > Finally, with the new roofing filters forthcoming from INRAD, a bunch of
> > > > older radios soon are going to have sterling dynamic range capabilities,
> > > > and you won't have to jump through hoops like the mods required on the
> > > > TS-870, or shell out big bucks.
> > > >
> > > >
> > > >        
> > > snip
> > >
> > >
> > >      
> > >
> > > > I wonder if George's new filters will have the effect of discouraging
> > > > introduction of new ham rigs since the older ones are being given such
> > > > powerful new legs?
> > > >
> > > >
> > > >        
> > > snip
> > >
> > > This will be an interesting one when the full story is told.  Certainly
> > >      
> so
>  
>
> > > far as the FT1kMP is concerned.  The roofing filter from Inrad has a 4
> > >      
> kHz
>  
>
> > > b/w which makes quite a good choice for SSB but is a lot of b/w for CW.
> > > Interestingly, the filter requires some additional amplification to get
> > >      
> over
>  
>
> > > its insertion loss and I understand that Inrad have opted to include
> > >      
> enough
>  
>
> > > amplification to get over that loss and add a little bit more.  What
> > >      
> price
>  
>
> > > that extra amplification?
> > >
> > > Figures published by Rob Sherwood
> > >
> > > http://www.sherweng.com/Dayton_2004/Dynamic_Range_Data.pdf
> > >
> > > show the following dynamic range numbers at 2 kHz:-
> > >
> > > TT-Orion 1 kHz roofing    92db
> > > FT1k MkV        70db
> > > FT1k            69db
> > > FT1kMkV Field     60db
> > >
> > > Sherwood also states that an additional 6-7db improvement in IMD at 2 kHz
> > >      
> is
>  
>
> > > obtained with the Inrad 762 filter.  This puts Orions range at 2 kHz up
> > >      
> to
>  
>
> > > 98db or better.  That's a full 28db better than the FT1k MkV and 38db
> > >      
> better
>  
>
> > > than the Field.
> > >
> > > That's a big gap and one that can only widen when the roofing filter mod
> > >      
> is
>  
>
> > > added.  The question is by how much?  As a CW man, I wonder whether the
> > > benefit in improved IMD at 5 kHz will outweigh the deterioration in IMD
> > >      
> at 2
>  
>
> > > kHz.  I have an MP but for now my roofing filter dollars will stay in my
> > > pocket.  Time will tell.
> > >
> > > Bob, 5B4AGN
> > >
> > >
> > > _______________________________________________
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> > >
> > >
> > >
> > >
> > >      
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> >    
>
>
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