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

[Joe Giacobello]

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 at swva.net>
>To: <tentec at 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 at 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
>>>
>>>
>>>_______________________________________________
>>>TenTec mailing list
>>>TenTec at contesting.com
>>>http://lists.contesting.com/mailman/listinfo/tentec
>>>
>>>
>>>
>>>
>>>      
>>>
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>>
>
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>  
>