[Boatanchors] antenna question

[Dale Parfitt]

That should work fine Ray,
The parasites "don't know" what is driving them. However, you may have to
alter the DE matching scheme to achieve an acceptable SWR because the
different (Mosley vs HyGain) parasite spacing and lengths will likely result
in different mutual impedance.

Dale W4OP

-----Original Message-----
From: Boatanchors [mailto:boatanchors-bounces at mailman.qth.net] On Behalf Of
RAY FRIESS
Sent: Friday, February 19, 2016 1:29 AM
To: boatanchors
Subject: [Boatanchors] antenna question

Need some advice or observations from antenna guys here.
I'm wondering how much interaction there is between traps and spacing in
triband beams?    I know that the antennas are designed with certain spacing
between the three elements, and what the traps in each do, which is
basically to present a resonant length for each band, using
the traps.

Here is what I am thinking:  I have a three element beam that has a bad trap
in one side of the driven element.  It is
a Hygain triband.   A friend of mine had his 50 foot tower come down today
in 85 mph winds.  On top of it, he had
a Mosley Classic 33.  The driven element seems to have survived with minimal
damage.
 What I am wondering is, can you "transplant" the Mosely driven element to
the Hygain, using
the current spacing of the Hygain.   In other words, everything would remain
the same with the Hygain, except the
driven element would be removed and the driven element from the Mosley would
replace it.  Or, are the designs so different that the spacing of a triband
elements depends in part on the design of the traps?

I thought it might be possible because each driven element is resonated on
the three bands with its own traps.
If the driven element of one was transplanted to the other, the three
elements would still be resonated with the traps they have.  OR, is the
spacing of the elements dependent on the traps too?
 		 	   		  
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