"hunt4mac" wrote in message
...
I have an Garmin Astro 220 GPS that uses the MURS frequencies, 151.82 -
154.60 Mhz. Using an online calculator I learn that the antenna should be
18.5 inches for 1/4 wavelength and 9.25 in. for 1/8 wavelength (based on
the 151.82 Mhz frequency)

.I was considering buying an antenna on eBay but it is only 8 inches.
(eBay item# one, eight, 1, 3, zero, two, 327, 578. Sorry for this
workaround, the admins think I'm posting a phone number).

How much difference would this mismatch cause? Or is it a mismatch?


I don't think you would have any mismatch as the shorter antenna is probably
a 'rubber duck' type. It is sort of like a spring inside the rubber
covering and loaded to match the frequency. Many Ham handi talkies use this
type of antenna on 146 MHz without any problem.
The range is slightly shorter with this antenna, but for tracking dogs I
would not think the reduction in range would really matter. Doubt they would
be over 1/4 of a mile from you.