True but when you change the harness to get down tilt (PER DB) you also
change the spacing. (Also per DB) .
It is also just cheaper to buy a new DB-224 for the two meter Ham band. You
get a new antenna and it will work for many years.
Lord knows they are cheaper then grits.
73 Russ,
----- Original Message -----
From: "Kevin Custer" <[EMAIL PROTECTED]>
To: <Repeater-Builder@yahoogroups.com>
Sent: Monday, January 24, 2005 5:46 PM
Subject: Re: [Repeater-Builder] Re: DB224 "Loop" Lengths for 145.110 Mhz?
>
> russ wrote:
>
> >Hey every one,
> >Let us not forget that they change the spacing to get down till on the
DB-224.
> >
>
> Wrong.
>
> The only way to get downtilt on a binary fed exposed dipole array is to
> either build the phasing harness so the electrical length feeding each
> element is slightly longer in phase with respect to the one next to it,
> or mechanically tilt the array if it is a cardiod pattern. Varying
> spacing between elements has little effect on the vertical beam pattern.
>
> There is very little difference in the performance of a dipole array
> with varying amounts of spacing between the elements. Most
> manufacturers shoot for about 80 to 90% of a full wavelength between
> elements, but the spacing is really not that critical. Also, the amount
> of pipe above the top element is not critical as long as there is enough
> to maintain the impedance of that element. It could be 2 inches or 2
> feet, as long as the match is okay it doesn't matter.
>
> The spacing of the element from the mast (reflector) affects impedance
> greatly. Don't try to mount your Cushcraft AFM-4DA or 44DA on a
> fiberglass or plastic mast pipe. It won't work....
>
> Kevin Custer
>
>
>
>
>
>
> Yahoo! Groups Links
>
>
>
>
>
>
>
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