[Hammarlund] HQ-120-X crystal filter patent

[Richard Knoppow]

    I think I mentioned the Hammarlund patented crystal filter in 
an earlier thread. I found it again (from an old post by me).
The patent is _Selective Wave Transmission_, USP
2.222,043 applied for in 1939 and issued in 1940. I had
thought it was earlier. The inventor is Donald K. Oram.
-- 
Richard Knoppow
1oldlens1 at ix.netcom.com
WB6KBL