[time-nuts] antennas was Re: Common-View GPS Network

Sarah White kuzetsa at gmail.com
Tue Apr 16 20:19:57 EDT 2013


On 4/16/2013 1:55 AM, Jim Lux wrote:
> On 4/15/13 10:22 PM, Jim Lux wrote:
>> On 4/15/13 9:27 PM, Tom Van Baak wrote:
>>> NIST SIM GPS common view pinwheel
>> described in one of the NIST reports as an aperture coupled slot fed
>> array that is better than a patch, but not as large and heavy as a choke
>> ring.
>>
>>   W. Kunysz, 2000, “High Performance GPS Pinwheel Antenna,” in
>> Proceedings of the 2000 International Technical Meeting of the Satellite
>> Division of the Institute of Navigation (ION GPS 2000), 19-22 September
>> 2000, Salt Lake City, Utah, USA (ION, Alexandria, Virginia), pp. 2506-251
>>
>> http://www.novatel.com/assets/Documents/Papers/GPS-704xWhitePaper.pdf
>> Patented by Novatel & Pinwheel is a trademark
>>
>>
>> Performance is almost as good as a choke ring but a heck of a lot
>> smaller and lighter.
>>
> 
> of course, cake pans with 2-2.5 inch high walls are readily available.
> 
> There's a Wilton cakepan set with 6",8" and 10" diameter pans with 3"
> walls.. hmm, an inch between fins..
> 
> Oddly, the package shipping size is 12x12x2"... I wonder how they fit a
> 3" high pan in a 2" thick box..
> 
> a real restaurant/pastry supply has a mindboggling variety of pans
> 
> http://www.fantes.com/cake-pans-round.html
> 
> every integer inch diameter from 4" to 18" and ditto for heights from 2"
> to 4"...
> 
> 
> People like those machined or cast choke rings because they're easier to
> fabricate: Slap a block of aluminum in the lathe or milling machine,
> push GO on the CNC, and stand back.
> 
> Or for those with a taste for hot metal.. you could cast it with scrap
> aluminum you've melted in the forge in your time nuts lab..  Turn those
> empty beer cans into something useful.
> 
> If you have a fancy multiaxis mill, you could probably do one of those
> porcupine looking things.
> 
> Or, if you have a swimming pool or pond, and some sheet aluminum, and
> some suitable high explosives.. hydroforming is your friend.
> 
> If you want true timenuts.. do the explosive hydroforming without a
> mold/buck, and instead use precision timing of shaped charges.  Finally,
> a use for those krytron switches you found at the surplus place.

Thanks for that. The last bit of your post was really cute. I needed a
good laugh :)

I haven't posted much in a while, partly because I've been kinda bummed
out by this list since I got the news about shera... There have been so
many constant reminders of his passing and whatnot (multiple thread
titles mentioning his legacy)

I just have to ask though... cake pans? really? I can't imagine it would
even be possible to modify a cake pan with enough accuracy to get a
usable antenna.

-- Sarah


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