Got it Saturday and drove away from one collar using the rubber duckie.
When I lost signal with the rubber duckie I installed the small double folding antenna and started receiving signal from the collar.
After several tries using both antennas, I have determined that the small folding antenna gets about double the range as the rubber duckie.
Here is a link to the site for the antennas:
http://cgi.ebay.com/Garmin-Astro-220-GP ... 3014r25247





