[Hammarlund] Mechanical filter for SP-600?

[Craig Roberts]

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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