Guy wire insulator spacing summary ORIGINAL QUESTION: Does Anybody Know the magical length for spacing egg insulators along ur guy lines? Tnx AL7CQ Lloyd REPLIES: The point is to avoid resonant lengths. The ARRL Antenna Book has a chart that will help you figure out which ones are appropriate for your needs. --Trey, WN4KKN/6 ------------------------ It has always been my understanding that you should break up metallic guy wires every 27.5 feet. I'm sure there are variations on that theme, but that seems to be a good number. 73, J.P. AA2DU ------------------------ From the ARRL Antenna Book: <15.0' 27.5' 39.5' --|--widest nonresonant ranges 58.0' --| 76.0' Of course there are also longer lengths but these are the ones I have used in building my Contest station. Note that even nonresonant lengths can seriously detune a nearby antenna which is why I'm replacing half of each guy on my tower with fiber rod. To find out how your guys may affect your antennas try one of the various antenna modeling programs (ELNEC, AO etc.) or use K6STIs GUY.EXE utility. 73 Bill N6CQ@paonline.com ------------------------ I used 27.5 feet as the magic number for guy wire breakups, and had problems with detuning on 20. I have a fixed KT34XA mounted just below a guy bracket on rohn 45. The guys caused the SWR to go above 2:1 on 20 meters. I tested the theory by temporarily removing the guys from the guy anchors and bringing them in alongside the tower. One guy, the one most parallel to the driven element, was causing most of the problem. To solve the problem, I put about 6 big ferrite beads on the top section of the guy, located at the middle of the 27 foot length. Problem solved! -Tony, K1KP, fisher@hp-and.an.hp.com ------------------------ I remember hearing 20 or 21 feet was the magic number. It is confusing hearing all these different numbers. I ended up doing overkill. I used 10 foot lengths except near the ends of the guy wires. I was real concerned about side mounted antennas working, and wire antennas that might be parallel to the guy wires. I liked the idea Tony presents: using RF beads. I have thought about using them to "break up" an electric fence I have which prevents me from running a beverage along the edge of my property. I guess they would have to be spaced every quarter wave or so. This isn't a lot of beads to make a beverage possible (I can even do multiple turns). Maybe with some tricks, I can use the same wire for the electric fence! When I want to listen on 160, I can remotely turn off the fence charger, switch a relay to connect the line to a transformmer, and use a bead a quarter wavelength from the corner and another one at the corner. The termination resistor would go across the first bead. Rt ---o |-/\/\-| Xo------------------------------------B----------B Bead o Relay Bead | | | | | | | | | | | Fence Charger <--------------------about 600 feet--------------> A different twist to the question, "Can I use electric fence wire for a beverage?" Rest assured, I will use real antenna wire, not the steel stuff. Can anyone think of any reason this wouldn't work? Could the quarter wave stub be at a right angle to the rest of the beverage so I could make the active part of the beverage a quarter wave longer? I estimate the height would be 4 feet or so... maybe a little low for a beverage, but I don't have to worry about people running into it. I might have another wire in parallel below it, which I would detune with the beads every quarter wavelength. Thanks for any input. Tree N6TR tree@cmicro.com ------------------------ 14 Feet has been bandied about.. For a tower with beams, some articles suggest that only the first section of guy immediately under the beam, or a couple of sections immediately in front and adjacent, for a stacked beam looking through the guys, are necessary...If you are loading the tower on 160, or such, then only resonant lengths for that band need be done... Denny k8do@aol.com