[time-nuts] DIY QFH

[Jim Lux]

On 11/28/13 6:27 AM, Chuck Harris wrote:
> As far as I know it is L1 only.  It is a Bullet II HE, P/N 25045-10,
> the standard antenna specified in the Thunderbolt manual.
>
> If you look closely, you will notice that what appears to be a
> single soldered joint at the middle, is really two solder joints,
> one on each of the sides of the preamp's PCB.

OK.. didn't see the double solder at the top, it looks like one in the 
photo.

>
> Each "V" has different length legs.  The legs are drooped down to
> where they are capacitively loaded to the ground plane.
>
> So, what it is is two inverted V type dipoles in parallel, and
> oriented at 90 degrees crossed.

And the classical approach of make one dipole a bit long and the other a 
bit short to get the 90 degree phase shift needed for CP.