TO: ALL WEST VIRGINIA ARES MEMBERS (OFFICIAL)
ALL ARES AND NON-ARES AMATEURS ANYWHERE (INFORMATION)
FROM: KEN HARRIS WA8LLM WV SECTION EMERGENCY COORDINATOR
WOOD COUNTY EMERGENCY COMMUNICATIONS INCORPORATED
WV ARES® BULLETIN NR 10.37 DATE: September 12, 2010
SUBJECT: HOW MUCH POWER SHOULD WE RUN?
The FCC must have had something in mind when they limited us in the amount of power our radios could transmit. What was it? Transmit only the amount of power which is necessary to make the communications.
Does this mean we should start at 100 watts and then decrease, or start at 10 watts and increase? It ONLY says that we should transmit the amount of power which will allow us to communicate. If we can communicate easily by using 1/2 a watt then that is our power limit. However, many mobile radios only reach 5 watts minimum, so in this case 5 watts is our limit.
If we run our mobile units at 15, 25, or 50 watts instead of making that communications on 5 watts, this is unnecessary, and may cause interference, and has broken the rules.
Remember that if you are using a beam antenna, you are concentrating your power in one direction. If your antenna has a gain of 10 db, then your 5 watt radio has a signal strength that's equivalent to about 50 watts, which may be way more than you need to communicate. With that kind of power you may be interfering with communications beyond the station you are communicating with. If you are using a beam to communicate through a repeater, you may be bringing up repeaters hundreds of miles away.
If you can communicate with a non-directional antenna and 5 watts, that's the system you should use.
The FCC Rules are not only for VHF and UHF, they also apply to the High Frequencies Bands too.
Ken Harris WA8LLM
Wood County WV
WV ARES® Section Emergency Coordinator
WV ARES® District 3 Emergency Coordinator