[Boatanchors] Haligan and Xtal Filters

[Dave Brown]

Likely a key issue. There are xtal filters and xtal 
filters.......although I would have thought all these were single xtal 
types but different circuits might have been considered different 
enough to justify a separate patent.
 Some relevant info here....

http://www.ieee-uffc.org/freqcontrol/crystal.html

73
Dave
ZL3FJ

----- 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: Thursday, December 11, 2008 11:04 AM
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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>> Date: 12/8/2008 6:16 PM?
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>
>> ?
>
> _______________________________________________?
>
>
>
>
>
>


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