[Towertalk] LPDAs...
Steve Katz
stevek@jmr.com
Mon, 18 Nov 2002 07:46:22 -0800
> Steve,
>
> What about putting the whole " Variable Geometrie " in a protected
> environment, such as a light air pressure. The envelop could be some kind
> of reenforced Mylar already used fot baloons........
> Make me think about those big Boeings equiped with Awacs Radar, that isn't
> science fiction.
> Quite sure there must be some twisted weird who thought about this before.
> Funny to have a flying saucer on top of the tower.
> Jos
>
[Steve Katz] Jos, when cost is no object, all sorts of things are
possible! I worked on the AWACS program in the late 1970's and that was a
"cost plus" contract from USAF. The more it cost to build, the more all the
contractors and subcontractors made on it. I was extremely pleased to sell
semiconductors into that program (to G.E. in Utica, NY, who made the
transmitters at the time) for about $1900 each...similar to the ones you
might use in your own amps for about $2 each. But better. -WB2WIK/6
> ----- Original Message -----
> From: "Steve Katz" <stevek@jmr.com>
> To: "'on4kj'" <on4kj@skynet.be>; <Jim@shawresources.com>; "Jon Ogden"
> <na9d@speakeasy.net>; "Dino Darling" <k6rix@arrl.net>;
> <towertalk@contesting.com>
> Sent: Thursday, November 14, 2002 11:21 PM
> Subject: RE: [Towertalk] LPDAs...
>
>
> > Hi Jos,
> >
> > I'm all for it, and recommended this already. I don't have the
> bandwidth
> > for such a project myself, nor am I a mechanical engineer; however I'm
> > certain such expertise exists, possibly right here on this reflector!
> >
> > I'm not sure how to make an affordable telescoping boom that will
> withstand
> > operation in ice and snow, but it can probably be done. Maybe
> pneumatics!
> > I can hear it now, "Hold on George, I have to change bands...let me open
> > this big valve...whoooooosh...."
> >
> > WB2WIK/6
> >
> > "If everything seems under control, you're just not going fast enough."
> -
> > Mario Andretti
> >
> > > -----Original Message-----
> > > From: on4kj [SMTP:on4kj@skynet.be]
> > > Sent: Thursday, November 14, 2002 2:39 PM
> > > To: Steve Katz; Jim@shawresources.com; Jon Ogden; Dino Darling;
> > > towertalk@contesting.com
> > > Subject: Re: [Towertalk] LPDAs...
> > >
> > >
> > > The SteppIR can obviously be adjusted to make a beam pattern over an
> > > octave
> > > or more, and to create a good match to its feedline, by infinitely
> varying
> > > all the element length combinations; but it will never be optimized
> on
> > > more
> > > than one band because of the fixed element spacing.
> > > -------------------------------------------
> > >
> > > Steve,
> > >
> > > Why should one not realize a boom with mobil elements.
> > > Its not impossible, just find a good team totake up the challenge.
> > > After all radio amateur activity is not only commercial business,
> pseudo
> > > chicken band.
> > > What say !
> > > Jos on4kj
> > >
> > >
> > >
> > > > Can't comment on SteppIR wind/WX survivability, etc, since I don't
> think
> > > any
> > > > have been up long enough yet. In a few years, we'll know more on
> that
> > > one!
> > > >
> > > > -WB2WIK/6
> > > >
> > > > "If everything seems under control, you're just not going fast
> enough."
> > > -
> > > > Mario Andretti
> > > >
> > > > > -----Original Message-----
> > > > > From: Jim Shaw [SMTP:Jim@shawresources.com]
> > > > > Sent: Thursday, November 14, 2002 8:52 AM
> > > > > To: Jon Ogden; Dino Darling; towertalk@contesting.com
> > > > > Subject: RE: [Towertalk] LPDAs...
> > > > >
> > > > > QUESTION: Instead of an LPDA, why not use a 3 element SteppIR
> > > antenna?
> > > > > Don't they cover all frequencies continuously from 13.9 to 30 MHz?
> > > Isn't
> > > > > that similar to the design goal of an LPDA? Seems like a SteppIR
> > > should
> > > > > easily cover MARS frequencies in that range. Just asking cause I
> have
> > > no
> > > > > first hand experience with either and LPDA or a SteppIR.
> > > > >
> > > > >
> > > > > 73 de Jim WA6PX
> > > > > JGShaw@Alumni.HAAS.org
> > > > >
> > > > > -----Original Message-----
> > > > > From: towertalk-admin@contesting.com
> > > > > [mailto:towertalk-admin@contesting.com]On Behalf Of Jon Ogden
> > > > > Sent: Thursday, November 14, 2002 6:41 AM
> > > > > To: Dino Darling; towertalk@contesting.com
> > > > > Subject: Re: [Towertalk] LPDAs...
> > > > >
> > > > >
> > > > > on 11/14/02 12:17 AM, Dino Darling at k6rix@arrl.net wrote:
> > > > >
> > > > > > I learned more about LPDA's from this article than anything I've
> > > read
> > > to
> > > > > > date! I will have to re-read the article myself, but I remember
> > > talk
> > > > > about
> > > > > > front-to-back figures that were BETTER than a small yagi.
> > > > >
> > > > > I could believe they have better F/B than a small Yagi. I also
> > > believe
> > > > > that
> > > > > a good sized LPDA would outperform a small beam. However, I am
> not
> > > > > completely sold on the idea of absolutely better performance.
> > > > >
> > > > > I'll have to look into it since I am currently perusing what sort
> of
> > > > > antenna
> > > > > to get to replace my TA-33.
> > > > >
> > > > > 73,
> > > > >
> > > > > Jon
> > > > > NA9D
> > > > >
> > > > > -------------------------------------
> > > > > Jon Ogden
> > > > > NA9D (ex: KE9NA)
> > > > >
> > > > > Citizen of the People's Democratic Republik of Illinois
> > > > >
> > > > > Life Member: ARRL, NRA
> > > > > Member: AMSAT, DXCC
> > > > >
> > > > > http://www.qsl.net/na9d
> > > > >
> > > > > "A life lived in fear is a life half lived."
> > > > >
> > > > >
> > > > > _______________________________________________
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> > > > > See http://www.mscomputer.com
> > > > >
> > > > > Wireless Weather Stations now $349.95. Call Toll Free,
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> > > > _______________________________________________
> > > > AN Wireless Self Supporting Towers at discounted prices,
> > > > See http://www.mscomputer.com
> > > >
> > > > Wireless Weather Stations now $349.95. Call Toll Free,
> > > > 888-333-9041 for additional information.
> > > > _______________________________________________
> > > > Towertalk mailing list
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> > > >
> > >
> > _______________________________________________
> > AN Wireless Self Supporting Towers at discounted prices,
> > See http://www.mscomputer.com
> >
> > Wireless Weather Stations now $349.95. Call Toll Free,
> > 888-333-9041 for additional information.
> > _______________________________________________
> > Towertalk mailing list
> > Towertalk@contesting.com
> > http://lists.contesting.com/mailman/listinfo/towertalk
> >
>
>
> _______________________________________________
> AN Wireless Self Supporting Towers at discounted prices,
> See http://www.mscomputer.com
>
> Wireless Weather Stations now $349.95. Call Toll Free,
> 888-333-9041 for additional information.
> _______________________________________________
> Towertalk mailing list
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