A few of you have asked about different antennas that can be used in a Portable situation and so here are my ideas on the topic… Before we start on that lets look at my defination of a Portable Station… A Portable Station is a station that you can carry from the parking lot to where you are going to operate from in one trip.
The South African Amateur Radio Group uses a 1 km distance for their RADAR (Rapid Deployment Amateur Radio) stations . So lets say that if you can’t carry it …. its not a portable station and if you can carry it then you should be able to carry it around the block…
I think the best way to try and define RADAR to the North American Amateurs is that you take ARES operators and turn them into SOTA operators… You now have trained communicators who can also get to the effected area and set up communications in a situation that most of us would not want to even try… (Rambo of the Radios)
If it takes you more than one trip for any reason then its a “Transportable Station” Nothing wrong with these stations whatso ever. A Field Day style station would be concidered “transportable”
Firstly the antenna you choose should be one that you can deploy quickly as the idea is to spend more time on the air than time spent getting on the air. Lets keep it simple but efficient. There are easy to build antennas as well as a great deal of commercal antennas manufactured for the Amateur Community but… They have to be efficient and simple….
After playing portable with my FT817 for years now I have grown quite fond of the End Fed style of wire antennas. These are often described as EFHW (end fed half waves) but some are longer/shorter than the actual 1/2 wave length. Depending on which antenna book you read you can build one of these for a nominal amount of money and no special tools or skill is really required…
Depending on what frequency you wish to operate on you also will need a good source of cheap (but strong) insulated wire
Band (m)……….Antenna length (Rough estimates only for the length)
6m……….108 inches
10m……….16.5 feet
12m……….19.5 feet
15m……….24.5 feet
20m……….33 feet
40m……….66 feet
80m……….132 feet
160m……….264 feet
When you are building your own EFHW most likely you will need to build a matching circuit for it or you will need a balun and some sort of tuner… Lots of easy to build stuff out there on the www along with schematics as well..
One nice and easy thing about installing an EFHW is that there is no ground needed and its easier/quicker to install than a dipole as you only need two supports (or one if you use it as a sloper) Toss it over a tree limb… tie it off at both ends and connect it to your radio and you are on the air…
I use a Par End Fed for 10m to 40m and I have a “homebrewed” W3EDP (in an end fed configuration) which serves me quite well for 10m to 80m and it will also load up on 160 but is not the most efficient. There are some other companies that make end fed antennas for the hf bands and I am not saying anything bad about them. I just can’t say anything good about them as I have never tried one out…
In closing the EFHW will work in any configuration… Vertical, Sloper, Inverted Vee, Flatop or NVIS… It has the same basic charastics as a dipole (NVIS or Flatop) and in just easy to put up in the field… Well worth it if you choose to buy one and definately well worth it if you choose to build one…
But ( and there always is a but….) You need more than one antenna in your kit because there always is that one chance that the location you want to operate from will not allow you to get the EFHW stretched out in the way you want it to…
Another antenna I have great results with recently is the 31 foot vertical… For lots of really great pictures and stories about them do a google search for S9 antennas… Using the MFJ telescopic 33 foot pole I managed to clone the 31 foot S9 Vertical and it worked great for me… I put out a random radial pattern and feeding it with a 4:1 balun (yes you do need one) an auto tuner and a bout 25 feet of cheap RG58 coax it worked great fo me. I just leaned the antenna mast into the tree and used one bungee cord to keep it from moving and it worked great for the 5 hours that I operated for… If your really stuck you can use the 33 foot pole to support the end of your EFHW
There has been lots of debate about radials for these types of verticals and here is my $0.02 worth… Longer is better than shorter and more is better than less… When operating portable I try and get one 30 foot radial and a few (2 or 3) 20 footers stretched out at least. When stretching out radials remember to mark them so the people who are walking close by will find them and trip with no problems… I mark mine with a combination of yellow do not cross this line tape and orange trail marking tape and they still stare at the radials as they walk over them tripping and then look at them and me with a strange look on their faces..
A commercial antenna that is well worth the money would be the Buddistick antenna. This is a 6m to 40m portable antenna that packs up real small and fits in my backpack. It just about clamps on to anything and I have made some great contacts with it in the past… In my case my primary antenna would be the EFHW and the backup would be the Buddistick. If I’m going anywhere new or distant I always take both antennas with me… Better to be safe than sorry…
On that topic a great suggestion is that you assign a chunk of coax to each antenna you plan to take out to the field… When I take my buddistick out I have a 10 foot lenght in the buddistick case… When I take the W3EDP out I have a 25 foot length in its bag and when the Par goes out with me I have a 5 foot lenght in its bag…
Keep the coax with the antenna and you won’t suddenly find yourself missing something when you get to the field….
So there you have it… A few suggestions for antennas that you can use in the great outdoors… All of them are fairly lightwight and easy to set up… But they are suggestions…. They do work for me but they might not work for you… All three of them meet my needs (EFHW, Vertical and Buddistick) which is multiband operations and also quick installations time…. Remember that I want to spend more time on the air than spending time to get on the air…
Hope this helps you in your quest to play radio in the great outdoors…
73bob
