[R-390] Question - Dave Curry Longwave Products Mechanical Filters - Stil...

[ToddRoberts2001 at aol.com]

Rockwell-Collins sells a line of Low Cost Torsional Mechanical filters. I 
believe these are the ones used in the Curry Longwave Products filters. You can 
order these directly from Rockwell-Collins in small quantities. They are small 
enough to fit inside a round metal tube the same size as the original R-390A 
filters. With a little ingenuity you can make up your own custom filter for an 
R-390A using one of the Low Cost Rockwell-Collins filters. Available 
bandwidths are : 300Hz, 500Hz, 2.5KHz, 5.7KHz, 7KHz and 10KHz. 73 Todd WD4NGG.