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eHam Forums / Antennas and Towers and more / RE: Mechanical Thoughts About My Tower
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on: October 10, 2012, 04:39:03 AM
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Fred, it is normal when assembling sections together to have them mate past their hole alignment. DO NOT REDRILL! It is also very important to use the prescribed hardware, and not just any bolt and nut. New sections are supplied with a bolt and nust set in one of the legs. If these are old sections, the bolts may be missing. Rohn sells a bolt pack to satisfy one section. Four sections require 3 bolt packs, plus 1 for the bottom joint, and possibly 1 more depending what's going on top.
Occasionally, you may need a leg alignment tool when joining the sections, and then something to help break them apart years down the road. A TowerJack works great for this. A small bottle jack works in a pinch for separation too.
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62
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eHam Forums / Elmers / RE: PowerPoles
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on: October 10, 2012, 04:22:08 AM
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I only soldered, but recently purchased a "do-it-all" crimping tool, so it's just a matter of installing the correct die for coax connectors or powerpoles.
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63
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eHam Forums / Antennas and Towers and more / RE: CHICKEN WIRE FOR VERTICAL GROUND RADIAL SYSTEM
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on: October 09, 2012, 12:04:44 PM
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I think the key is not to bury it. Sitting on top of the field or lawn is fine. Here in WMA, there's a big contest station that uses an elevated 80m 4 Square Array. The system employs a spider web of traditional overhead radials and they work fine. But for contests, large spools of chicken wire are unrolled onto the mowed pasture around each antenna. After the contest, the chicken wire mats are rolled up and stored below each of the four towers so the pasture can be mowed. That galvanized wire mesh has been out in the elements for years and shows absolutely no signs of rust or corrosion.
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64
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eHam Forums / Mobile Ham / RE: Yaesu 8900 antenna recommendations
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on: October 07, 2012, 07:54:04 PM
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Of course you'll need a diplexer. You can use 3 NMO mounts with one particular triplexer and get all four bands with 3 antennas. I have that triplexer, but just haven"t installed it yet. I can get that model number if.you want.
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68
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eHam Forums / Antennas and Towers and more / RE: Ascending lanyard recommendations?
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on: September 26, 2012, 06:28:50 AM
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I though about installing a fall arrest cable system on my tower, now that I am old and feeble.
At 62 I know the feeling, Tom! You might be right about that. I was concerned about pulling the arresting folds out if I put any weight on it. But perhaps it takes a lot more weight on it to do that. 38379 is what I'm looking for. Thanks!
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72
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eHam Forums / Mobile Ham / RE: ATAS 120 activating door locks
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on: September 20, 2012, 07:44:10 AM
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Mark, I was plagued with common mode issues initially when I installed my IC-7000 with a hitch mounted screwdriver antenna. It would scramble the BCB receiver, and actually shut the rig down if I ventured above 50 watts output. I did a number of fixes to get rid of it, but the two things that made the most improvement were: 1) Connect the transceiver directly to the vehicle body with a 2" wide, short copper foil strap. 2) Connect two copper foil straps from the antenna ground to the vehicle body, and to the vehicle frame like so: http://i9.photobucket.com/albums/a96/TwoSevenRight/bond4.jpgAdditionally, I bonded the doors, hood, hatch, and exhaust system to the vehicle body. The results were remarkable, and I got the added benefit of a much lower noise floor. Ignition noise became nearly nonexistent. http://i9.photobucket.com/albums/a96/TwoSevenRight/bond1.jpghttp://i9.photobucket.com/albums/a96/TwoSevenRight/bond2.jpghttp://i9.photobucket.com/albums/a96/TwoSevenRight/bond3.jpg
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74
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eHam Forums / Elmers / RE: Comet GP-15 tri-bander - missing radials
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on: September 14, 2012, 07:31:30 AM
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There are three radial as you already know. Two of them appear to be radials for the 2m band; around 19" long. The third radial is for 6m. It's a bit longer than the other two, but here's the rub: It has a loading coil midpoint with an adjustable whip. Obviously, the loading coil shortens the overall length of the radial. The user adjusts the whip of the 6m radial for the portion of the band they wish to use. If you're missing all the radials, I don't know what the effect would be if you replaced the loaded 6m radial with a "full size" 1/4 wave radial. I recall having to adjust mine several time before it played nice within the section of 6m I wanted to use.
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75
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eHam Forums / Antennas and Towers and more / RE: HF verticals, recommendations
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on: September 12, 2012, 04:54:40 PM
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.......I will mount it above my roof on a mast....... Rick W7HBP
If you desire to roof mount, or elevate the vertical above the earth, keep in mind that any quarter wave radiator will require (at a minimum) two radial wire cut to a quarter wavelength* it's velocity factor. Elevated multband verticals can be problematic, especially for a new name with little to no test equipment. Consider that 4 bands could have up to twelve radial wires of various lengths, all interacting with one another. It can be done, it just takes patience and time.
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