[TowerTalk] 5 Band Yagi with more than 2 elements per band

[Tom_N2SR]

 Align by sight?    
Ever hear of a level?   
When I first got back on the air, I used a TH7 for about 2 years.  When I put that antenna back together (I had it stored in my garage), I bolted the boom to my tower, about 3 feet off the ground.   I used temporary ropes to hold up the ends of the boom, and leveled the boom - with a level.   
For the elements, I cut two 2 inch "thick" pieces of 2X4- exactly the same thickness.  Not 2 1/8".  Not 2 1/16".  Exactly the same.   Tape each piece to each end of the level.   Now you can place the level across the boom / boom to element clamp, and level each element.   
IMO, the problem with the Hy-gain clamshell is the center bolt with the square nut which is supposed to hold the elements level.   With my TH7, after the element was level I drilled a hole through the hole and through the boom and used a stainless steel bolt with two flat washers (one on top and one on the bottom), a lock washer and a nut.   OMG, I did something most people here will consider scandalous.  
IMO, the "worst" element to boom mounting is the Cushcraft.   Cheap U bolts, thin aluminum tubing.  
Tom, N2SR


    On Wednesday, July 25, 2018, 10:17:32 PM EDT, Jim Thomson <jim.thom at telus.net> wrote:  
 
 Date: Wed, 25 Jul 2018 14:59:30 -0400
From: rlvz at aol.com
To: towertalk at contesting.com
Subject: [TowerTalk] 5 Band Yagi with more than 2 elements per band

<But don't the JK antennas use muffler type clamps for attaching the elements to the boom where the elements must be lined up by sight?? I hate fooling around aligning elements by sight only to have them change when you tighten the clamp.??Pre-<drilled element brackets are much nicer and my idea of a well designed antenna.

<73,
<Dick- K9OM

##  Nope,  JK uses massive machined aluminum  2 piece wide clamps, with loads of surface area.  Muffler style clamps are history these days, good riddance... they have virtually  zero surface area. 
But I know what you mean by the oem F12  boom to ele brackets,  saves a bunch of time.  Flip side is... IF the yagi is needed to be re-tweaked, and ele spacing adjusted,  it’s a gong show with the F12  style brackets..esp aligning them.
There is zero room for error.  They must be drilled  precisely. 


##  For a real horror  show, the hy gain cast,  clamshell style..  boom to ele clamps, I found, were a bitch to align properly.    One could spend a long time aligning  a TH-11.  IMO, the worst  designed boom to ele clamps  bar none. 


Jim  VE7RF

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