GB> technical help needed

[Brian Wood]

In my article on the "DZ3" 3-element 5-band "monobander" (July, 2001 QST), I
used the dimensions given by W2PV in an Antenna Book article. He used 0.2005
wavelengths for driven element to 1st director and 0.1235 wavelengths for
driven element to reflector spacing, with element lengths slightly lesss
than 1/2 wavelength. I modeled it on Brian Beezley's "YO" program and got a
respectable front-to-back and gain on each band.

Fluidmotion, on the other hand, chose to use an identical spacing for the
two distances just mentioned, since they can adjust element length
dynamically.

73,

Brian, W0DZ

-----Original Message-----
From: Heathkit Owners and Collectors List
[mailto:HEATH at LISTSERV.TEMPE.GOV]On Behalf Of Crawfish
Sent: Tuesday, December 24, 2002 6:33 PM
To: HEATH at LISTSERV.TEMPE.GOV
Subject: Re: GB> technical help needed


Most of the info I have seen show 0.2 wavelength spacing between the driven
element and the reflector, and .1 to .15 wavelength spacing between the
driven element and the director, and .1 to .15 wavelength spacing between
directors.
                                                                    73,
                                                                    Joe
W4AAB
----- Original Message -----
From: rayfri <rayfri at networld.com>
To: <glowbugs at piobaire.mines.uidaho.edu>; <HEATH at LISTSERV.TEMPE.GOV>
Sent: Tuesday, December 24, 2002 3:00 PM
Subject: GB> technical help needed


> need some advice.  Whats the formula or method for determining how far
> behind a driven element the reflector should go?
> I'm building a 20 meter beam.  The driven element will be a shortened
> one...
> a dipole 102 inches on each side with loading coils on each half of the
> dipole at the
> feedpoint.  I know that reflectors are usually 5 percent longer than the
> driven element, but I need to know the formula or method for figuring
> how far behind the
> driven element to put a reflector.
> Ray  wa7itz
>
>

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