The tower trailer(s) you see are owned by private ham radio operators in your area. We use them with our own events to get antennas or antenna wires up in the air where they can be most effective. We also use our equipment in community events that we volunteer for. So far there are 8 of these owned by volunteers in the state of MN. We have found used/retired construction light tower trailers to be very cost effective for what they can do for us.
Ham radio operators are unpaid volunteers typically using their own equipment (yes, we bought these!).
If you’d like to know more about Ham Radio please visit www.arrl.org. Ham radio is a fun hobby.
What could the tower be doing?
- It could be running an amateur radio repeater. A repeater is basically an antenna and hardware that receives fainter signals from small radios and re-transmits with the benefit of higher power and/or better antenna or placement. The result is that smaller, hand-held radios can be useful for more distance.
- It could be creating a self-forming mesh network using free router firmware software from http://www.arednmesh.com. This provides a network that the towers can use to talk to each other using TCP/IP for monitoring, telemetry, camera access, or other purpose. Video feeds are generally used by our served agencies – usually the support personnel for whatever event we are helping with.
- It could be integrating into and providing service for a radio network, such as DMR (see http://www.mndmr.net)
- It could be used for tracking event resources during an event for medical team support; or to track pickup buses or other vehicles, perhaps using a protocol called APRS.
- It could be here to help with a purely ham radio related contest or activity.
In all likelihood the trailer may be doing more than one of these activities at the same time.
How much distance can you get with one of these?
- VHF/UHF frequencies typically used for voice are may get 35-50 miles, depending on conditions (and height – these frequencies are line-of-sight coverage typically).
- The tower trailer 30′ masts with vertical FM antennas (+5 feet) have a calculated/tested range of about 9 miles.
- The mesh technologies work differently – each “node” added to the network both adds access and extends the network for all other nodes. The range depends on how many hops are available. Mesh range is line of sight. Any trees/hills/buildings block the signals.
- Long, wire-based antennas are probably used for HF communications. HF communications typically benefit from atmospheric conditions and world-wide conditions are possible. Thousands of miles is typical.
In any case, if you see any ham radio folks around, feel free to approach us with your questions.
There are also many local amateur radio groups in the Twin Cities area that may be able to answer your questions. Consult http://www.arrl.net for a list of affiliated clubs.
http://anokaradio.org Anoka County Radio Club is the local club that the author belongs to.
If this all looks fun to you, let us know! We’ll help you get started. See the main page at http://www.hamtowertrailers.com. If you want, you can see if you can find which trailer you’re looking at by looking at our list.