[TowerTalk] Shadowing of small antennas by larger ones?

[Guy Olinger, K2AV]

I'm at work, so don't have my diagrams to look at, but I seem to recall that the 40N series DE has an inductor at the center for impedance matching, so it really ISN'T a split dipole. 

The conundrum you mention is one of the reasons to NOT use a split arrangement -- reduce variation in characteristic due to feedline differences. Someone might want to use a dedicated feedline. 

I'll check the diagrams when I get home and post a confirmation tonight. 

Someone may 

73, Guy.

> 
> From: n4kg@juno.com
> Date: 2001/02/01 Thu AM 11:25:43 EST
> To: TOWERTALK@contesting.com
> Subject: Re: Re: [TowerTalk] Shadowing of small antennas by larger ones?
> 
> What makes you think that a 40M SPLIT  DIPOLE, 
> Linearly Loaded, will exhibit a resonance on 15M?
> 
> That may be true for a CONTINUOUS, SELF resonant
> full size 40M element (that is gamma or T-matched)
> but NOT for a split and loaded element.  In fact, the
> exact resonace can be moved around by changing
> the length and termination on the feedline.
> 
> de  Tom  N4KG
> 
> 
> On Wed, 31 Jan 2001 17:23:24 -0500 "Guy Olinger, K2AV"
> <k2av@contesting.com> writes:
> > Read the description carefully. On the C39, the 40 DE is BETWEEN the 
> > 15 DE and the 15 reflector, NOT behind the 15 reflector. 
> > 
> > They HAVE had to deal with removing the 21 mhz resonance from the 40 
> > "N" elements. The diagram is at home, but the distance from the 40 
> > DE to the 15 DE on the same boom is a LOT less than the vertical 
> > mast separation the original poster proposed between the separate 
> > antennas.
> > 
> > > 
> > > From: n4kg@juno.com
> > > Date: 2001/01/30 Tue PM 11:51:25 EST
> > > To: TOWERTALK@contesting.com
> > > Subject: Re: [TowerTalk] Shadowing of small antennas by larger 
> > ones?
> > > 
> > > You can put lower frequency elements BEHIND higher frequency
> > > elements because the high frequency reflectors isolate other
> > > elements to the rear.  
> > > 
> > > That is NOT the case for vertical separation where the lower
> > > frequency elements are symmetrical about the mast as are the
> > > higher frequency elements on the triband antenna.
> > > 
> > > de  Tom N4KG
> > > 
> 
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