Of course, the suggestions on my "2M EME TIPS" page still apply, but setting up a small or portable station for 2m EME can actually make it quite easy to make contacts, since many of the complexities are avoided. For example, here are some guidelines which would enable a small station to make contact with dozens of the larger 2m stations around the world:
1. ANTENNAS - In the simplest station, you would need only one very good antenna. For best results, the antenna should be the longest yagi possible. Using only a single antenna immediately simplifies things because there are no power dividers or phasing lines - just a single transmission line. It also makes aiming easier, since the pattern is broader (the antenna only needs to be moved every 20 minutes or so), and you do not have to worry about multiple yagis getting out of alignment by pointing different directions. In a simple/portable station, it is frequently very effective to further simplify the aiming by keeping the antenna pointed at the horizon only, and using "armstrong" manual rotation (in which case, the azimuth can be determined with a simple protractor placed around the mast). Usually, it is very easy to put a yagi up on a portable mast that is only about 7m tall - high enough to be out of the way and low enough to have a short feedline. A 2m antenna that high above the ground will typically have its main lobe at about 5 degrees elevation, with a second, weaker, lobe up around 12 degrees elevation. That usually means that the moon (either rising or setting) will slowly pass through two antenna lobes within the course of a one hour schedule.
If desired, manual elevation is also very easily accomplished by mounting a protractor on the rear end of the boom, and watching the reading indicated by a stiff wire mounted through a hole in the center of the protractor (the wire is free to pivot and always hangs straight down due to gravity). I have successfully used such arrangements for hundreds of EME contacts when I was operating from C6A. The boom-to-mast clamp was simply a pivot, and the antenna can be held at the proper elevation by tying a nylon string (attached to the rear end of the yagi) down to a rock or concrete block. Very low tech, but it doesn't break and it isn't expensive! Remember, though, that you lose ground gain if you point the antenna up in the sky!
A very effective single yagi for 2m (especially designed for portable use) is the "2M8WL" 15 m long yagi manufactured by M-Squared in California. The antenna comes in a box only 20 cm x 20 cm x 218 cm long (weighing about 12 kg) and 1999 costs were in the $339 range. More information can be obtained by contacting M-Squared at (559) 432-8873 (telephone) or (559) 432-3059 (FAX).
2. GROUND GAIN - By pointing on the horizon, you make the installation very simple. You also take advantage of GROUND GAIN, which can add 6-8 db more gain than the single antenna would have if pointed up in the sky! That can make it equal to as many as 6 yagis! To get that much ground gain, you must use a horizontally polarized antenna.
The ground gain is especially good if the antenna can "look out" over salt water to see the moon setting or rising. That can mean amazing performance for a very small antenna! For example, the first time I operated from ZF8, I had only a 7 element beam (the horizontal 7 elements of a 14 element satellite yagi) and 500 watts, yet I made half a dozen random EME contacts on my moonrise (out over the ocean). If you have a flat, clear horizon - especially if is is over salt water - put it to work for you!
3. FEED LINE - With a portable station it frequently is possible to have very short feedline. This makes the transmitted signal louder, and makes it possible to hear stations without a preamplifier mounted on the antenna itself. A 15 or 20 m length of a good low loss coax such as LMR600 "ultra flex" would make an excellent installation.
4. RECEIVING PREAMPLIFIER - If the transmission line is short and low loss, the receiving preamplifier can be located right at the operating position. This greatly simplifies the installation, since relays and preamplifier do not need to be located up on the tower (along with their separate coaxial and power cables).
5. AMPLIFIER - The biggest problem with a smaller station is that it will be difficult for larger, more powerful stations to hear you, even though you will hear them (especially when the moon is near your horizon!). If you can achieve more than 200 w at the antenna, you should be able to make contacts with at least 10 of the larger stations on 2m EME. If you can have 400+ watts at the antenna, you can probably make contacts with a couple dozen stations, and if you have 800+ watts at the antenna, it should be possible to make many contacts - especially if you use the ground gain on the horizon. And, of course, if you have a 1500 watt amplifier, you probably will be able to complete a contact with just about everybody you can hear.
An amplifier that has been very successfully used
by many portable EME stations during DXpeditions is an amplifier using
the 3CX800 tube. It only requires 25 watts drive, is compact and
easily transported, and can put out 800-1000 watts if the AC power provided
is adequate. These are available commercially from several manufacturers
around the world ( Command
Technologies, for example), or there are plans
in various publications showing how they can be constructed. A larger
amplifier (that can be used on both 6m and 2m) using a pair of 3CX800's
is available from Alpha-Power.
You don't need a huge station to have fun and successfully make 2m EME
contacts! Why not get started and try it out!