Saturday, April 30, 2016

Operating Simplex FM

We have all listened to or participated in uhf or vhf Ham Radio nets. A common practice on a repeater net is to take mobile or portable check-in's toward the beginning of the net. This can be for any number of reasons but most specific is to allow people who have the potential of moving out of range to go first or to allow people who do not have sufficient power or antenna systems more time to relocate to make contact. (continued below...)

We depend on these nets to practice orderly and efficient relay of messages for future times of need. What we don't realize though is that many, if not most repeater sites are located in areas with smaller potential for power emergencies. Many of these areas are not prepared in the event power is not available for extended periods of time. Not to mention any weather related event could take the antenna system out of service. Then what would we do for local communication efforts?

Most Ham Radio operators do not practice simplex nets in the VHF or UHF bands. This takes a special skill and turns things around a little. I heard a couple of ham radio operators the other day joke at the fact that there were people who wanted to run UHF and VHF simplex nets. They said all repeater sites today have backup power systems and ham radio operators need to practice their nets on the repeaters. I must say these hams are misinformed. Besides, what is going to happen to their precious repeater when a major storm destroys the repeater antenna?

It is important to know the capabilities of your radio equipment if you have to operate in simplex mode. This is where you do not use a repeater and all transmit and receive is on the same frequency. You will find that the distance is much shorter.

If you are running a UHF or VHF simplex net call for the high power stations to check-in first. This will allow you to operate in a greater geographic area. The high power station may be able to relay traffic from a distant low power station. Utilization of relay stations is important on these types of nets.

The overall key is to practice in simplex mode. Know the range limitations of your equipment. Work on solutions to be able to relay messages across distances. This may require you practice with friends who are also preparing for communications disasters as well. You can even use HF operators to connect to distant stations and relay traffic to and from your VHF net. Explore the possibilities!

Have you operated in VHF or UHF nets? If so, I would like to hear about your experiences. 

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