[Elecraft] analyzer seeing near field effects- clarification

[vze3v8dt at verizon.net]

Thanks for the clarification, John.  So I think the analyzer would best 
help you determine the impedance match which may be affected by those 
various affects and proximities that you refer to.  It won't tell you 
what your radiation pattern will be.  Certainly coupling to nearby 
metalic objects can detune an antenna (and change radiation patterns) 
and so the adjustment of its location to minimize those affects would be 
something you could see with such an analyzer, w.r.t. impedance and 
SWR.   You might best if possible find a location to mount the antenna 
that has minimal affect from nearby conductors.  Presumably minimal 
affect may also result in less distortion of the desired radiation 
pattern as well.   However, in some cases the spacing of a vertical 
antenna a given distance from a metalic object (mast, wall, etc) can 
give possibly desired directional characterists as well, always 
something to consider.

Mark, NK8Q
K2 4786

jferg977 at aol.com wrote:

> Comrades,
> what I was wondering was whether an analyzer would help me locate and 
> tune an antenna on my boat.  I was hoping to find out whether it would 
> "see" the capacitance and other effects of several of the large metal 
> structures above deck. I was hoping that I would be able to move the 
> antenna around, maybe tip it a bit, adjust its ground connections and 
> try a lot of things and have some hint of progress show up on the 
> analyzer. I was hoping I would be able to see whether grounding these 
> other structures was worthwhile or indifferent.  I am not likely to 
> have to deal with strong adjacent signals nor other structures.  All 
> "near-fiield" effects will be caused by a large radar arch (aluminum), 
> an aluminum jib crane (dinghy lift) and the other antennas.  As 
> always, I'm astonished at the knowledge available on this reflector 
> and am appreciative of the help I'm getting.
>
> John Ferguson
> M/V Arcadian
> _______________________________________________
> Elecraft mailing list
> Post to: Elecraft at mailman.qth.net
> You must be a subscriber to post to the list.
> Subscriber Info (Addr. Change, sub, unsub etc.):
> http://mailman.qth.net/mailman/listinfo/elecraft   
> Help: http://mailman.qth.net/subscribers.htm
> Elecraft web page: http://www.elecraft.com
>