[TowerTalk] Stacking Distance for M2'd 6m7JHV?

[Jim Lux]

At 11:08 AM 7/12/2004 -0400, TexasRF at aol.com wrote:
>Max stacking gain for dipoles is 5/8 wavelength. Max stacking gain for yagis
>varies with boom length. For the 6m7JHV with a 30ft 8in boom length, stacking
>distance will be in the 25 to 26ft range. As always, before cutting and
>drilling the stacking should be confirmed by one of the yagi modelling 
>programs.
>
>You can stack closer but the maximum realizable stacking gain will not be
>reached. In this case, you could be better off with a single longer yagi than
>understacked yagis. If the stacking is wider than optimum, the gain doesn't
>suffer but the main lobe becomes skinnier and other grating lobes become 
>higher in
>amplitude.
>
>73/k5gw

And this is at a particularly interesting frequency.  You're at that point 
where the atmospheric noise is fairly low, so gain (as opposed to raw 
directivity) does start to be important, because you're working against the 
receiver noise.