[time-nuts] Difference in GPS antennas

[David I. Emery]

On Fri, Aug 14, 2009 at 08:03:58PM -0700, Hal Murray wrote:
> 
> > My Panasonic VIC100 antenna had a few screws to hold the bottom to the
> > plastic cone top.  The bottom had an o-ring seal that stuck a little
> > but was still pretty easy to slide the bottom from the top half.
> > Inside was a patch antenna on top of a pcb. 
> 
> Thanks.  I tried again and it came apart easily.  There is an O-ring but no 
> glue.  (I wonder why I didn't get it the first try.)
> 
> The antenna isn't a patch.  (Or I don't recognize it as such.)
> 
> It's a cylinder, 2 inches tall, 3/4 inch in dia, sticking up over a 2 inch 
> square PCB that's screwed into an aluminum base place.
> 
> It's made of flexible PCB material wrapped around to make a cylinder.  The 
> outside bottom 3/4 inch is a plane.  There is an obvious solder joint line 
> closing the plane.  The inside top has 4 fingers spiraling around at 45 
> degrees.  The lower inside part (opposite the plane) has some wiggles in some 
> traces, but I haven't figured out the equivalent circuit.

	Quadrafiler helix... feed for it with matching networks, combiner and
phasing delays in microstrip.



-- 
  Dave Emery N1PRE/AE, die at dieconsulting.com  DIE Consulting, Weston, Mass 02493
"An empty zombie mind with a forlorn barely readable weatherbeaten
'For Rent' sign still vainly flapping outside on the weed encrusted pole - in 
celebration of what could have been, but wasn't and is not to be now either."