The AM Forum

Here is a question for the board:

The two verticals will interact somewhat.

So.......If we want the cardioid, is it just as simple as 1/4 apart and shorting the OWL 45 degrees down from point A, or is it necessary to do something along the lines of Christman phasing? If so, how to find appropriate line lengths?

BTW, I think a "backwards Pi" would be a reasonable match circuit.

The end fire case is easy enough.

Thoughts?

https://f6aoj.ao-journal.com/cariboost_files/rotate_20the_20bobtail_20curtain.pdf

One other point:

If you terminate the OWL section with a variable cap.....say a butterfly with decent spacing, you can "walk" a virtual short up and down the line by simply adjusting the capacitor.  No climbing ladders to set the phasing.