SUBJECT: VHF/UHF stealth beam antennas Let's look at a couple of points here first. From my last posting, the relative sizes of the different antennas show that hiding a 6m antenna can be a lot more difficult than hiding a 70cm antenna. 6m beams can be large and hard to explain as a TV antenna. Many PUDs/Condos/ Apartments do not permit TV antennas at all. For places that allow TV antennas, I have some tricks that you can do inorder to play on the bands. These tricks will be discussed later. Beams are a necessity in some locations. The gain achieved on a beam can mean the difference between getting in the repeater, digi-node, making a simplex or SSB contact. The easiest installation would be in an attic, but most hams can figure that out. Unless you only require a fixed position, a beam will require a rotor to fully utilize the quality the a beam can provide. Beams are generally single band antennas when used above 10m. I would recommend a log periodic for use on the VHF/UHF frequencies to provide the ham with multi-band operations. There are some problem that must be addressed when working with beams. First, different polarities are required for different operations. FM and packet use vertical while SSB and CW require horizontal. Space communications requires a combination of the two or circular polarization. Second, hiding a beam and it's associated support equipment can be a pain in the butt when the QTH says no antennas. Anything that must rotate is going to draw attention. Fixed beams can be hidden. Rotating beams are going to require a bit more. ------------------------------------------------------------------------- Remember that size plays a big point when stealth is employed. I'll look at the 2m beam for the examples here and the relation can be applied to the other bands. Horizontal operation: This is the easiest beam to hide. Be sure you know all the rules of your association or apartment before attempting to install a beam. The beam, because of it's polarity, is flat. It can be passed off as a TV antenna for a specific channel. Most people wouldn't know the difference. The outside installation can be accomplished with the basic TV installation. By adding a second rotor, such as an elevation rotor, both vertical and horizontal polarization can be accomplished. I recommend the vertical operation for night time use only. It eliminates the question; "Why is your TV antenna like that?" Stealth operation: You may not be able to put up a TV antenna and must totally hide the beam. Attics are an easy hiding place. Upper rooms are good too. Telescoping elements for portable operation work well. I would like to relate some unique installations to overcome the no antenna rules. This Amateur had a bad time trying to locate any antenna at his dwelling. He lives in an apartment complex. His apartment is on the inside, second floor, of a four story apartment building that is shaped into a large rectangle. ----------------------------------------- | | | | | --------------------------- | | | | | | | | | | | | | | | | | | --------------------------- | | X | | | ----------------------------------------- The X indicates where the apartment is located. There is an apartment on the outside of his. Like I mentioned, he was on the second of four floors. No antennas are allowed outside the apartment. He had a couple of options. One, he could move, but funds weren't there. Two, he could use his noodle to figure out how to beat the system. This ham enjoys UHF operations from 440-450. He also works 2m packet from time to time. Most people would stick to stamp collecting at this point. There are additional problems facing this ham. Windows on the upper floors would expose him to masts, cables and devices to raise or lower his antennas. On top of that, the roof of the building is steeply sloped. Mounting anything up there, let alone getting up there was a problem. A steeply sloped roof means a large attic. The ham in question is an electrician, by trade, and was employed by the owners of the building to rewire part of the top floor hallway lighting. The job was to take place in a weeks time. It was all the time he required to assemble a set of beams, with rotor control. The coax and control cables were to be run down next to the electrical conduit into his apartment. He purchased two beams, a 2m and a 70cm, to facilitate his requirements. A TV rotor was employed to rotate the set and the antennas were mounted side by side. The 2m beam was a simple four element model and the 70cm model was an eleven element model. In addition to the beams, he also installed two omni directional antennas. The total set was mounted to a short mast and base. It took a mere two hours to assemble the system and one hour extra to run the cables. He was in business. He mounted the system over a stairwell and service closet. He also mounted the base over a foam pad to inhibit the rotor noise. This ham is in the Central Florida area. He is a Technician Class operator and has been operating this way for over three years now. This is an example of fixed beam installation: This ham lives in a condo complex south of a large city. No antennas are allowed. His unit is on the second floor of a two floor unit. This ham enjoys 2m SSB. Since he owns the condo, this ham was able to modify the roof of his screened in porch to accommodate a unique masting system that can be raised and lowered from inside the porch. He employed a three section mast made from aluminum tubing. The eleven element 2m beam was fitted with rubber feet under all the elements and the boom. After that, the beam was painted a dark flat grey to blend in with the night sky, even under full moon conditions. The upper mast sections were also painted in the same manner. During the daylight hours, the beam was lowered against the aluminum roof and was well out of sight from the neighbors. At night, the beam was raised enough to clear the top of his roof. Raising the antenna mast took a bit of planning. The roof of the porch was 7'6" above the deck. A pulley system, similar to a patio umbrella device was employed to raise the mast sections. The mast was placed in the center of the roof and a table supported the base. A plastic vine type plant was used to disguise the bottom section along with a planter to finish off the stealth set-up. The coax was run to the planter and then connected to another coax when it was to be used. The ham in question has been operating this way for a few years with good success. The installation of a beam requires thought and planning. I can not give plans for every installation. This is mostly dependent on the amateur. But these ideas may give you some ideas on how to beat the rules and enjoy your hobby. 73, WS