[Antennas] 30 Meter Ground plane

Wed, 25 Feb 2004 20:06:41 +0100

Acording to KM5KG software. The voltage working voltage of the capacitor is
318 volts (assuming a capacitor Q of 3000), so a 500V unit will be enough.
But as a safety rule, try to get a higher voltage unit.

Fran - EC1CFD
----- Original Message -----
From: "WX5L" <[email protected]>
To: "Fran Dominguez" <[email protected]>
Sent: Wednesday, February 25, 2004 7:50 PM
Subject: Re: [Antennas] 30 Meter Ground plane

> If I am running 200 watts output what would be the working voltage rating
of
> this capacitor.
>
> Thanks,
>
> Randy
>
>
> ----- Original Message -----
> From: "Fran Dominguez" <[email protected]>
> To: "Antennas Mailing List" <[email protected]>
> Sent: Wednesday, February 25, 2004 10:57 AM
> Subject: Re: [Antennas] 30 Meter Ground plane
>
>
> > Hi Randy,
> >
> > you can try this simple solution. Use an L network: put accross the feed
> > point a capacitor of about 220pF (the calculated value is 225.7pF for a
> > center freq of 10.125Mhz) then make the antenna a bit longer that it
> should
> > be to get resonance. In this way the antena impedance will be 33Ohm in
> > series with an inductance. When the reactive part of the antenna
impedance
> > will be 0.4uH it will be perfectly matched to 50Ohm.
> >
> > You can download the trial version of "KM5KG RF Network Designer"
software
> > and play with its L Network calculator.
> >
> >
> > Hope this helps....
> >
> > Best regards.
> >
> > Fran Dominguez - EC1CFD
> >
> > ----- Original Message -----
> > From: "WX5L" <[email protected]>
> > To: <[email protected]>
> > Sent: Wednesday, February 25, 2004 1:35 PM
> > Subject: [Antennas] 30 Meter Ground plane
> >
> >
> > > Hello,
> > >
> > > For an afternoon project I built a 30 meter ground plane.
> > >
> > > I used the base section of an old 14AVQ and used some tapered aluminum
> > > sections to obtain the 23' 1" I needed. Also installed 4 radials in a
> > > horizonal plane 5% longer.
> > >
> > > The base of the vertical is 15' above ground on a steel mast. I also
> have
> > > the base of the vertical grounded with 3/4" braid to a 8' ground rod.
> > >
> > > I found the resonant point just about where I wanted but the lowest
swr
> is
> > > 1:7. I checked it with my MFJ anatenna analyzer and found the
impedence
> > > around 33 ohms.
> > >
> > > I'm looking for a way to match this 33 ohms closer to 50 ohms and
> keeping
> > > the RG8U that I'm using.
> > >
> > > I'm looking for not the most complicated way but KISS and use spare
> parts
> > > from my junk box.
> > >
> > > Any idea's.
> > >
> > > Thanks,
> > >
> > > Randy
> > >
> > >
> > > [email protected]
> > > Thibodaux, Louisiana
> > >
> > > - - -
> > >
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> > > Larry Wilson KE1HZ [email protected]
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> > >
> >
> > - - -
> >
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>