Re: [amsat-bb] helix location vs focus

[Dave Guimont <dguimon1@xxxxxxxxxx>]

>>   I read somewhere (can't remember) that you should place the
>>   bottom (i.e. feedpoint) of the helix at the focus of the dish.
>
>I seem to recall someone on this BB experimenting, and finding
>that the hot spot was at the end of the first turn for a simple
>helix.  My own experiments seem to put the hot spot at the mouth
>of the can, for "canned helix" antennas.
>
>The best thing to do is to create (or locate) a weak signal
>source, and adjust it for best signal.  Then, let the rest of
>us know where it is!
>
Hi Greg et al,

Very simple to determine, and it is very close to that.  I've been winding
and testing them since O13.

Glue half a dozen ~1" mirrors scattered around the dish. I use them to 
determine
the mounting length and approximate position for the helix.  Tune on a steady
beacon, and adjust for max smoke.  Then point back at the sun and inter-leave
a small piece of paper for the bright spot; hot, if u will....

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