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

[Jeff Blaine]

My experience with quite a number of the JKs is that they use machined 
aluminum clamp sets for the boom.  I personally don't like working with 
antennas on the ground so I build them on a trio of saw horses.  The 
element sag is less than the saw horse height on all my JKs so that 
allows me to do the alignment very easily.

The only muffler clamps I've seen on the JK are for the boom to mast on 
smaller antennas (15 & 10) - there he has 4x of the clamps and the 
clamps have a flattened and knurled surface which bites into the mast.  
The "problem" with these clamps is when you are setting the beam 
direction once it's mounted on the mast. They will absolutely not slip 
at all so you have to really loosen them up to get the beam to turn by 
hand.  Of course that is what you want after you do get the beam 
direction set.

73/jeff/ac0c
alpha-charlie-zero-charlie
www.ac0c.com

On 25-Jul-18 1:59 PM, rlvz--- via TowerTalk wrote:
> 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
>   
>   
> ## I spoke with Ken, W3JK a while back on the telephone, and yes, indeed, he does
> make a new and improved version of the oem F12 5BA. It has more gain, better FB,
> better FR, better swr than the oem F12 5BA, and is stronger built....and uses TWO LESS
> eles than the oem 5BA. The JK improved version is well though out.
>
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