[R-390] Antenna...folded dipole...

Tue, 16 Dec 2003 09:40:41 -0600

Maybe he's building a T2FD....doesn't it use a terminating resistor...and if
it is to be used for transmitting as well it may need to be of a large
wattage?

Just reading between the lines a bit...may be waaaay off base!

Cecil....
----- Original Message ----- 
From: "Kenneth G. Gordon" <[email protected]>
To: "Dave Faria" <[email protected]>
Cc: <[email protected]>
Sent: Monday, December 15, 2003 5:08 PM
Subject: Re: [R-390] Antenna...folded dipole...

> On 15 Dec 2003 at 10:56, Dave Faria wrote:
>
> > GM list.  I want to build a Folded Dipole antenna for my station.  I
> > can wind the balun but, cannot find a suitable terminating resistor.
> > Can anyone point me to a source for a non-inductive 400ohm or 800ohm
> > resistor 300 watt??  I can build a combination of resistors to meet
> > the resistance and wattage if necessary.
>
> No folded dipole I have ever seen in antenna books or other
> literature, or that I have built, ever needed a terminating
> resistor. If you plan to use this antenna with an R-390, my
> understanding is that the R-390's input impedance is already
> 300 ohms, balanced, and a properly built folded-dipole exhibits
> 300 ohms impedance, balanced, at the resonant frequency.
>
> Of course, the folded dipole is resonant only around one
> frequency or band, so you would have to have several
> depending on what bands you intend to listen to.
>
> Terminating resistors are only needed for antennas such as
> rhombics, Beverages (sp?),  and the like, not for a folded-dipole.
>
> Ken Gordon W7EKB
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