Tips for Portable Antennas
As you use portable antennas more often, you find ways to make them easier. Here are some tips that I have collected over the years.
Yes, it makes a difference. Make sure that your antenna location allows for a comfortable operating position. Having some sort of pad to sit on helps, even if you don’t have a chair. And pay attention to where you sit: I was honored to be another ham’s first contact once when I was out backpacking, sitting on the ground with the rig on a rock. While trying to describe my QTH in the wilderness at 3 WPM on CW, I discovered I was sitting on an ant hill, which made it difficult to send slow and steady CW.
attaching the coax
When putting up a portable antenna, make sure you remember to attach the coax before hoisting it into the air, and that you have enough coax that you can reach the bottom end of it once you raise the antenna.
what size wrench?
If you have an antenna or other item that requires assembly in the field, write on it what size wrench it needs. Even better, attach the required wrench to the antenna so you can’t forget it. If you need several wrenches, use colored tape to mark the tools and the corresponding points where they are used.
which element goes where?
The same thing with the elements for a yagi: I mark them with colored tape on both the element and the boom. That doesn’t prevent errors, but it makes them less likely.
For assembling a yagi in the field, I find that putting it up on a small tripod or a pair of saw horses permits assembly at a more convenient height.
Minimize the number of parts that have to be removed from the antenna (as opposed to just loosened and tightened). Paint the remaining parts bright orange, so you can see them if you drop them in the grass. Surveyor’s flagging / ribbon comes in many bright colors, and can be attached to larger parts: 10 to 20 cm (4 to 8 inches) is generally enough to make them easier to find. And take spare parts with you.
A magnet on a stick may help to recover small steel parts like screws and nuts, unless they are stainless steel.
Sometimes you need to make emergency splices to your wire antennas in the field. While the traditional “Western Union Splice” twisted splice works well for larger solid wire, it is a poor choice for the smaller stranded wire sizes often used for portable operation. One problem is that the wire insulation provides a significant portion of the strength of the wire, and just splicing the conductors together makes a very weak joint (especially if soldered!)
The solution is to tie the insulated parts of the wire together with a knot, leaving long enough ends that they can be stripped and connected together electrically with no tension on the actual joint.
tying to a vehicle
If you use a vehicle as an anchor for a guy rope or an antenna, use a drive-on mount for a mast, or run a coax from a station to a mobile antenna mounted on a vehicle, make sure you run the coax through the steering wheel, or otherwise make it difficult for someone to drive off without thinking about the antenna. A friend tells the story of an expensive transceiver that did not survive being dragged out of a tent and down the road at the end of a length of coax.
With wires and such that tend to get tangled, put them in plastic bags. I started doing this for ear buds and other headphones when I had several pairs in a bin. Recently I was testing a lot of antenna wires, and this made it much easier to keep them separate (and the two wires for a dipole together).
pay attention to your surroundings
It is easy to get carried away when operating and not notice changes around you that might be important. By the ocean, pay attention to the tide tables and plan in advance when you have to leave. Same with darkness: set an alarm so you can get everything packed up and get back down the trail before dark. High winds and lightning can be dangerous: don’t wait until you hear the first boom of thunder to get down off a hilltop. Make sure a tree is sturdy and healthy before trying to climb it to retrieve your antenna wire: I was lucky to make it back to ground level one time before the tree fell over. Be alert for dangerous animals: wasps, bears, venomous snakes, scorpions, cougars, mosquitoes, ticks, keas, chiggers, or other local fauna that might make your operation less enjoyable.
weatherproofing coax joints
For temporary use while operating portable, plastic wrap from the kitchen can be used to weatherproof a coax splice. Just wrap it around the splice, making sure the ends seal against the cable. It should keep most of the rain off, anyway, even if it might not work when the joint is under water.