Hi All:
How many of you took the VOA tour at Mason Ohio. For many years they had a
large fixed Quad array aimed at Europe. This was what the Tour person told
us. They removed the Quad after many years and replaced it with a ( I
think )a large bobtail curtain. After taking the tour about 4 times I never
saw a Yagi of any type.
Bill ( yes I manufacture Quads ) Wall KC4UZ
----- Original Message -----
From: "EUGENE SMAR" <spelunk.sueno@prodigy.net>
To: <TOWERTALK@contesting.com>; "Pete Smith" <n4zr@contesting.com>
Sent: Sunday, November 17, 2002 9:41 AM
Subject: Re: [Towertalk] Loop Gain (was LPA designs)
> TT:
>
> FWIW: Back in the late 80's I was involved with designing a relay
> station for VOA in the Negev Desert in Israel. The intended application
was
> to receive satellite-borne audio from Washington DC studios and retransmit
> the material to south-central Asia (Afghanistan, Kyrghystan, Kazahkstan,
> etc.) The US-based transmitters couldn't broadcast to that area directly
> due to Soviet jammers. The main transmit array was a series (three, I
> think) of curtain arrays that could be slewed a few degrees in azimuth and
> elevation by changing the phasing of the feeds. The arrays were to be
> supported between towers that were three hundred feet tall. (Antenna area
> was measured in acres, not square feet!) I believe Saber was the intended
> manufacturer, but I could be mistaken. The transmitters (Continental
among
> other mfrs) were going to be 100 kW jobs and the ERP was enormous (I can't
> recall the figures.)
>
> The site was also going to include a large LPDA for 6 - 30 MHz up at
> 100 feet on a rotator (SS, here I come!) This antenna was a backup for
the
> programming, in case the satcom feed failed. It was also going to be used
> with a "QRP" 50 kW transmitter for order wire comms for TTY and who knows
> what else.
>
> The whole thing was going to be computer-driven based on propagation
to
> the intended target sites and the program schedule. So basically I know
of
> at least one SW broadcast facility that included both curtain arrays and
> LPDA's in its antenna line-up.
>
> 73 de
> Gene Smar AD3F
> P.S. Then glasnost came along and Mr. Gorbachev silenced the jammers.
The
> project was never constructed. Sigh.
> -----Original Message-----
> From: Pete Smith <n4zr@contesting.com>
> To: TOWERTALK@contesting.com <TOWERTALK@contesting.com>
To: <towertalk@contesting.com>
> Date: Saturday, November 16, 2002 2:44 PM
> Subject: Re: [Towertalk] Loop Gain (was LPA designs)
>
>
> >At 11:28 AM 11/16/02 -0600, Jon Ogden wrote:
> >>on 11/16/02 10:49 AM, Zyg Skrobanski at af4mp@mindspring.com wrote:
> >>
> >> > I don't think I've seen Yagi's used by any SW broadcasters.
> >>
> >>Probably not. It's too narrow in bandwidth and probably too
directional.
> >>
> >
> >Actually, when I lived in Taiwan in the late 1960's, there was a
religious
> >broadcasting station there that used a three-element tribander (modified
> >for BC frequencies, I assume) to broadcast to the mainland. The quad
> >parasitic array was, I believe, developed at broadcast station
> >HCJB. Today, VOA et al frequently make use of curtain arrays that,
> >depending on their configuration, can be very directional indeed. One of
> >the other things that is (or was) on the F12 web site was N6BT's
> >description of using a 21 dBi gain broadcast curtain in a DX contest.
> >
> >
> >73, Pete N4ZR
> >Sometimes a tower is just a tower
> >
> >
> >
> >
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>
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