On Sunday 27 January 2008, Kirk Wallace wrote:
>On Sun, 2008-01-27 at 15:03 -0500, Gene Heskett wrote:
>... snip
>
>> Interesting John. But the whole idea has threads about interferometer
>> based methods going around in my head, and the thought of the single
>> frequency coherence required to make that work keeps backing away from the
>> relatively expensive he-neon lasers that still require some filters to
>> achieve a
>
>... snip
>
>> help in the ambient noise cases. This is however, well above the shops
>> local crickets I'd bet...
>>
>> I'll email them for a quote just for grins & giggles.
>>
>> --
>> Cheers, Gene
>
>What about micro-waves?
Those frequencies are doable, but again I'd think I can do it cheaper
acoustically. My highest frequency experience has been with Gunn diodes
running at about 23GHZ, where a 60 mw signal successfully penetrated about
1.5 miles of a pouring it out of a boot rain one night several years ago. I
got soaked to the skin in 35F degree weather setting up the gear on the roof
of the country club, but the gear was fine till it blew over in the wind and
I had to grab a cement block and some rope to go weight it down again. I
believe that wavelength is still a bit long for these sorts of measurements,
and stepping on up in frequency seems to get expensive fast.
FWIW, Gunn's aren't that stable, they have a phase noise that means the video
you ship over them with a 4 mhz deviation, comes out the other end with its
SNR reduced to about 40 db, best signal.
--
Cheers, Gene
"There are four boxes to be used in defense of liberty:
soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
Bloom's Seventh Law of Litigation:
The judge's jokes are always funny.
-------------------------------------------------------------------------
This SF.net email is sponsored by: Microsoft
Defy all challenges. Microsoft(R) Visual Studio 2008.
http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/
_______________________________________________
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users
