[ARC5] 77 GHZ

[Geoff]

I thought the Brits and MIT Rad Lab developed the magnetron during WW2.

Carl


----- Original Message ----- 
From: "Tom Dawson" <wb3akd at earthlink.net>
To: "David Stinson" <arc5 at ix.netcom.com>; "ARC-5 List" 
<arc5 at mailman.qth.net>
Sent: Friday, November 15, 2013 2:50 PM
Subject: Re: [ARC5] 77 GHZ


>I think the prize goes to Cleeton and Williams at U Mich in the early '30's 
>for discovering the absorption spectra of Ammonia at 24 (I think)  GHz.
>
> Used Western Electric Magnetrons as models and scaled them down in size to 
> the desired frequency to generate the RF.
>
> Polished brass parabolic mirrors on transmit and receive, selenium rod as 
> a detector.
>
> Wavelength measured with metal diffration gratings.
>
> Ammonia at 1 ATM in a rubberized canvas bag, they observed absorption of 
> the microwave energy.
>
> The idea came from their consideration that if quantumtheory was true, 
> then there ought to be an absorption line at 24 GHz or so, and they found 
> it. Opened up the field of microwave spectroscopy, as far as I know.
>
> Pretty durn neat for the time.
>
> 73
>
> Tom
> ----- Original Message ----- 
> From: "David Stinson" <arc5 at ix.netcom.com>
> To: "ARC-5 List" <arc5 at mailman.qth.net>
> Sent: Friday, November 15, 2013 1:40 PM
> Subject: Re: [ARC5] 77 GHZ
>
>
>> Similar surprise:
>> I have an Aircraft Radio Corporation 1945 catalog, flogging their surplus 
>> parts from cancelled contracts at the end of WWII.
>> All kinds of Command Set parts being offered.
>>
>> But they were also offering feedlines, cavities
>> and other "plumbing" for 21 GHZ.
>> Who knew anyone was "plumbing" 21 GHZ in 1945?
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