Sinclair SD210 open loop antenna

The Author has been making commercial antennas for years. This is a report for a another commercially made one.

This one is built for a heavy duty application for an amateur station on a remote high site with ice loading. It consist of two open loops with a coaxial harness (inside), mounted on a aluminum pipe. It has good return loss. The feed point is terminated with a type N male connector and is at the bottom of this pipe.

Shown here is the temp. setup for testing the antenna for return loss sweep and transmit to receive associated desense (if any). Since it's near the ground the results are expected to be slightly less than higher up on a tower. At the amateur operating frequencies appears to be good; about 19 db. The Tx to Rx desense is less than 1 db. The Author would recommend this antenna for repeater use at a medium to high site that does not have harsh winter conditions such as ice loading.

This may be copied in complete form only for non-profit purposes, such as for the knowledge for the Amateur Radio Service, with the Author credited as designer. For other arrangements please contact the Author.