[time-nuts] Difference in GPS antennas

Bruce Griffiths bruce.griffiths at xtra.co.nz
Sat Aug 15 03:13:26 UTC 2009


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.
>
>
>   
Thats a quadrifilar helix antenna.

bruce




More information about the time-nuts mailing list