TO: ALL WOOD COUNTY EMERGENCY COMMUNICATIONS AMATEURS
ALL NON-WOOD COUNTY EMERGENCY COMMUNICATIONS AMATEURS
FROM: KEN HARRIS WA8LLM
WOOD COUNTY EMERGENCY COMMUNICATIONS INCORPORATED
WV ARES BULLETIN NR 09.40 DATE: October 4, 2009
SUBJECT: RUBBER DUCKY YOU'RE THE ONE
Rubber duck antennas on hand-held radios are a severe compromise on efficiency.
On the plus side is their short size and flexible forgiveness to brutish handling. On the negative side is their terrible radiation inefficiency, probably worse than many of you expect. When did you last replace your helical spring antenna we call a rubber duck? On testing a hundred or so portable radios that had been out on the fire lines (In service) for a few weeks, California RACES found a typical 60 percent failure rate. Most of the antennas looked fine. The only way you can detect an invisible rubber duck failure is by measuring the micro volts per meter with a calibrated receiver over a measured range under controlled conditions.
Since this is difficult for most of us to do, it might not be a bad idea to just replace rubber ducky antenna as a matter of course, when they show signs of wear or, if they are more than a few years old.
You might want to consider using a telescopic antenna under non-violent conditions to vastly improve the range of your hand- held radio.
In any case, if you have problems maintaining good hand-held radio communications on a repeater, that normally has no problem, don't always blame the repeater. At least not until you have checked that rubber ducky antenna. It may be the problem.
(Reprint, with modification, of ARES District 3 Bulletin NR 07.16, by Duane Jones, N8LDM)
Ken Harris WA8LLM
Wood County WV
WV ARES Section Emergency Coordinator
WV ARES District 3 Emergency Coordinator