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Author Topic: R-7 Cushcraft Ant.  (Read 8332 times)

K4ARD

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R-7 Cushcraft Ant.
« on: February 06, 2001, 12:35:53 AM »



  I have a R-7 Cushcraft vertical Ant., still in box..Since I've been away from hobby for years..Can I put it on my 40 ft. tower ? Someone said maybe I couldn't.
  In advance, Thanks for reply.

 Regards,
 Brian ka4zrf
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WB2WIK

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R-7 Cushcraft Ant.
« Reply #1 on: February 06, 2001, 05:43:52 PM »

Of course you can.  Whether you really want to or not is a different matter.  This is a tall antenna that catches substantial wind which creates a serious bending moment at the antenna's base.  If the R7 is the "only" antenna on your 40' tower, and the tower is strong and secure, there shouldn't be a problem.  But if the R7 is on a 1-1/4" diameter mast, with other antennas mounted to that same mast, and the mast projects several feet above the tower top, this is precarious -- or an accident waiting to happen.  Ironically, global (widespread) experience indicates this type of vertical works about as well at much lower installed heights as it does at 40 feet...so unless there's some strong, compelling reason to install it on a tower -- don't bother.  On a roof top, chimney, eave mount, porch, or even a 6' mast stuck in the ground, it will probably work just as well as on the tower.  Good luck!
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K4ARD

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R-7 Cushcraft Ant.
« Reply #2 on: February 16, 2001, 02:32:59 PM »


  Thanks for the help ...


 Regards,

  Brian  ka4zrf
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WB8YYY

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R-7 Cushcraft Ant.
« Reply #3 on: March 16, 2001, 12:47:59 PM »

WB2WIK has the right idea!  A vertical needs a clear view of the sky in all desired directions.  These radiate by design at low angles - say 5 to 15 degrees.  So if sufficiently located away from other objects so its views the sky well - very little is gained by placing it at significant height.  My R5 is mounted with the base about 10 feet off the ground on the front of a 1.5 story shed.  The shed is near the house but deep enough that the antenna has a good view of the sky as i have described.  Best DX to you.  
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WB9YCJ

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R-7 Cushcraft Ant.
« Reply #4 on: March 23, 2001, 01:41:20 AM »

Seems like I say something nice about an R-7 (i.e., it works on six), it gets slammed by someone who  compares it to a pair of six element stacked yagi's with a full sized rhombic on the side.
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WL7NO

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R-7 Cushcraft Ant.
« Reply #5 on: August 08, 2001, 03:25:02 AM »

I have had an R-7 at my QTH for almost 7 years now.  I have it mounted at about 15 feet and it works fine. The first year I had it I was concerned about the way it swayed in the wind but dozens of wind storms later it still is standing.  By the way, the strongest wind it took over the last seven years was a 90+ mph gust!

James DE WL7NO
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