[Towertalk] Loop Gain (was LPA designs)

[David Jordan]

British Telecom also used LPAs to provide global broadcasting from Rugby 
Radio Station.

EUGENE SMAR wrote:

>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>
>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
>>
>>
>>
>>
>>_______________________________________________
>>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
>Towertalk@contesting.com
>http://lists.contesting.com/mailman/listinfo/towertalk
>
>  
>



--- StripMime Report -- processed MIME parts ---
multipart/alternative
  text/plain (text body -- kept)
  text/html
---