Satellite operation is a really fun and adventurous part of Amateur Radio. The Low Earth Orbit or "LEO" satellites are especially easy to work given some practice. Satellites such and AO-51 "Echo", AO-27, and SO-50 "SaudiSat" are the three most popular "easy-sats" to work because you can operate on them with at little as a handheld and an Arrow brand handheld yagi. My first real portable satellite operations began when i bought a Yaesu VX-8R and started operating the easy sats after work with an arrow antenna.
Searching for a suitable fixed satellite antenna to use with the LEO satellites as well as give some of the CW/SSB satellites such as AO-7 and FO-29 a try, I found the Turnstile Moxon Rectangle. This antenna was first introduced to me in the ARRL Satellite Handbook which included an article by L.B. Cebik which explained their use for satellite communications.
L.B. Cebik created an amazing database on www.cebik.com which since his passing has been hosted by antennex which requires a free registration. A webpage he wrote called Simplifying the Turnstile Moxon Rectangle Fixed-Position Satellite Antennas covers the theory behind the antenna and is HIGHLY recommended. The ARRL hosts the QST article which is also included in the Satellite Handbook named A Simple VHF/UHF Antenna for Satellite Work on their Technical Information Service webpage (TIS). An ARRL membership is required to view the article, I can't avoid that and will not infringe on copywrites and host it here! Sorry!
I used the ARRL article for a basis of my design and measurements. Reading that article will provide a much clearer understanding of how this antenna was built. If you do not have an ARRL membership you may be able to find another version of the PDF in a Google search.
Cebik outlines the 2 meter VHF element dimensions in his article. I first cut the 2 meter reflectors which make up the bottom half of the antenna. Each reflector is made up of 40.23" aluminum rod, this is 29.05"+(2*5.59"). 29.05" is the bottom portion of the rectangle and 5.59" for each side of the reflector that is bent 90 degrees up to make the bottom part of the moxon rectangle. This can be clearly seen in Figure 5 and Table 1 of A Simple VHF/UHF Antenna for Satellite Work.
Using a file, I smoothed the cut metal to prevent it from catching on anything or cutting me. The aluminum is easy to work with so this is a simple preventative task. Filing down the burrs where the hacksaw cut also helps when securing the gap in the elements later on with the aquarium hosing.
A tubing bender makes bending the aluminum not only easy but also professional looking. The trick that I found useful was to measure from the ends and mark the 5.59" length that will be bent upwards. Put the aluminum rod into a vise an inch or two before the marking (the marking will be exposed from the vise). Then, using the tube bender, look straight down from above and align the mark with the inside edge of the bender. Doing this seemed to evenly distribute the excess rod on each side of the bend. However, it is really important that the total length of the reflector be 40.23".
The finished reflector element is shown in the picture to the left. It should be relatively straight forward to bend using the tube bender and a vice. I learned a valuable lesson! which is to only bend one side before mounting each reflector into the PVC pipe. I fabricated two of the turnsitle Moxon rectangle reflectors using these methods.
