View Single Post
Old 14-Sep-2018, 12:30 AM   #2
Retired A/V Tech
Join Date: Aug 2012
Location: S.E. VA
Posts: 2,355
Crossed dipoles form a turnstile antenna. In theory, it's a pretty good Omni with peaks at 0, 90, 180, and 270 degrees. There are slight nulls between those directions.

But holl_ands modeled it, showing that it is a little less Omni that theory indicates.

I don't do modeling, but that doesn't look like a 90 degree phase shift line between the crossed dipoles, so I don't have confidence in his model. How long is the feed line between your dipoles?
Attached Images
File Type: jpg Antennacraft FM Omni_1.jpg (150.5 KB, 65 views)
File Type: jpg Antennacraft FMSS_1_zoom.jpg (12.5 KB, 59 views)
If you can not measure it, you can not improve it.
Lord Kelvin, 1883

Last edited by rabbit73; 14-Sep-2018 at 12:59 AM.
rabbit73 is offline   Reply With Quote