[Hammarlund] Mechanical filter for SP-600?

[Jim Wilhite]

Seems to me there is a company called Longwave Enterprises that make 
substitute mechanical filters for Collins equipment.  Would they work?

I have seen their ads in Electric Radio.

73  Jim
W5JO

----- Original Message ----- 
From: "Cecil Acuff" <chacuff at cableone.net>
To: "Craig Roberts" <crgrbrts at verizon.net>; "Hammarlund" 
<hammarlund at mailman.qth.net>
Sent: Friday, January 14, 2005 7:49 PM
Subject: Re: [Hammarlund] Mechanical filter for SP-600?


>I know of a cost effective alternative.  I haven't tried it yet but Kiwa 
>makes a completely self contained high performance crystal filter module. 
>One has no active components and the other has some high quality 
>amplification on board that allows zero insertion loss.  It is not 
>sensitive to input impedance and best I remember has the proper output 
>impedance.  It is even suggested in some literature where a test was 
>performed on the amplified filter module that it would be well suited to 
>the SP-600.  I'll have to look up where I read that...I think it was in one 
>of the later Proceedings publications.
>
> I have wanted to give it a try but have not gotten around to doing it.
>
> Maybe one day!
>
> Cecil...
> ----- Original Message ----- 
> From: "Craig Roberts" <crgrbrts at verizon.net>
> To: "Hammarlund" <hammarlund at mailman.qth.net>
> Sent: Friday, January 14, 2005 3:55 PM
> Subject: Re: [Hammarlund] Mechanical filter for SP-600?
>
>
>> Bruce Sugarberg wrote:
>>
>> "I believe Collins offered one (a mechanical filter adapter).  (It was) a 
>> very small box that  contained the filter and a tube, and replaced the 
>> 1st IF tube...."
>>
>> Thanks Bruce. The reason I asked is because I ran across a web page that 
>> contains plans from G. E. Ham News of March-April 1957 for just what you 
>> described. It looks like it might be adaptable to the SP-600 and might be 
>> fun to try (though the price of mechanical filters takes a little of the 
>> fun out of it).
>>
>> Thanks again & 73,
>>
>> Craig
>> W3CRR
>> www.aerialacts.com
>>
>>>
>>>
>>
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