[Boatanchors] Haligan and Xtal Filters

[cemilton at aol.com]

 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 !?

>>?

>>?

>> _______________________________________________?

>>?

>?

> _______________________________________________?

>?

>?

>?

> -- 
> No virus found in this incoming message.?

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> Date: 12/8/2008 6:16 PM?

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> ?

_______________________________________________?



 

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