[Boatanchors] Haligan and Xtal Filters

[Duane Fischer, W8DBF]

That will take a bit of time for me to locate. I spent twenty-two months originally in organizing, researching and editing the HHRP material. Since I am totally blind, it is going to take me longer then it would a sighted compatriot to go through OM.    
    
I will research that for you as soon as I can and post the results.    
    
Take care -    

  ----- Original Message ----- 
  From: cemilton at aol.com 
  To: dfischer at usol.com ; km1h at jeremy.mv.com ; blimpboy at sonic.net ; boatanchors at mailman.qth.net 
  Sent: Wednesday, December 10, 2008 5:04 PM
  Subject: Re: [Boatanchors] Haligan and Xtal Filters


  Duane,

  What is the patent number and date?

  73
  W4MIL
  Chuck





  -----Original Message-----
  From: Duane Fischer, W8DBF <dfischer at usol.com>
  To: Carl <km1h at jeremy.mv.com>; BLIMPY <blimpboy at sonic.net>; boatanchors at mailman.qth.net
  Sent: Wed, 10 Dec 2008 4:57 pm
  Subject: Re: [Boatanchors] Haligan and Xtal Filters


  According to former Hallicrafters Chief Engineer, Fritz Franke, (and I have both a hand typed document as well as actual audio of it being said, Hallicrafters invented, and patented, the crystal filter and was the first company to incorporate it into a military receiver and later in an available to the public receiver. This was about 1937 +/- 
   
  ----- Original Message ----- From: "Carl" <km1h at jeremy.mv.com> 
  To: "BLIMPY" <blimpboy at sonic.net>; <boatanchors at mailman.qth.net> 
  Sent: Wednesday, December 10, 2008 3:41 PM 
  Subject: Re: [Boatanchors] Haligan and Xtal Filters 
   
  > Thanks for the dates. I have all the 30's QST's and enjoy reading and > rereading the articles. 
  > 
  > My FBX, FB7X, FBXA, or FB7XA, or whatever else you want to call it gets > used regularly on 30M with HB coils. Its a very credible performer there > and keeps an equally old 30W TX clone company. 
  > 
  > As far as the crystal filter, it was first described by William Cady in a > 1922 IRE presentation 
  > 
  > Carl 
  > KM1H 
  > 
  > 
  > ----- Original Message ----- > From: "BLIMPY" <blimpboy at sonic.net> 
  > To: <boatanchors at mailman.qth.net> 
  > Sent: Wednesday, December 10, 2008 1:41 PM 
  > Subject: [Boatanchors] Haligan and Xtal Filters 
  > 
  > 
  >> 
  >> Moore's "Communications Recievers" 3rd Edition page 5 has a 
  >> chronological chart showing the emergence of new technological features >> in 
  >> communications recievers. 
  >> 
  >> It was Lamb - a very prodigious contributor to radio technolgy - not 
  >> Halligan, who published a description of a superhet with xtal filter in 
  >> August 1932 QST. 
  >> 
  >> 
  >> The crystal filter first showed up commerically in Hendricks and Harvey 
  >> Custom variation 1 reciever, Dec 1932. 
  >> 
  >> Followed in quick sucession by Leeds Supreme (kit) , Hendricks and >> Harvery 
  >> variation 2, and then the National FBX, in March and April 1933 
  >> respectively. 
  >> 
  >> We know which of those was likely to have been made in any numbers. 
  >> 
  >> Following them.. a whole slew of really famous and even iconic radios >> with 
  >> crystal filters followed: 
  >> McMurdo Silver 
  >> Hammarlund Comet Super Pro 
  >> RME-9 
  >> Patterson PR-12 
  >> 
  >> In fact Hallicrafters didnt get on the bandwagon untill mid 1934 - long >> after 
  >> the crystal filter was an established fact of life in the few really good 
  >> radios of the day. 
  >> 
  >> Halligan did a lot of things... but introducing the Xtal Filter wasn't >> one of them. 
  >> 
  >> 
  >> What hallicrafters did primarily.. was make cheap radios that included >> features pioneered by others, and made and plenty of them. 
  >> 
  >> Kind of like Skoda made cars in the soviet union...( read 2 cycle clown >> cars) Halligan made the S-38 and other AC/DC sets, and sets without RF >> stages. 
  >> Whoopee ! 
  >> 
  >> 
  >> _______________________________________________ 
  >> 
  > 
  > _______________________________________________ 
  > 
  > 
  > 
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  > 
  >  
  _______________________________________________ 



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