Topband: History of directional MF antennas

[Renee K6FSB]

available here no membership required.

https://worldradiohistory.com/BOOKSHELF-ARH/Technology/Directional-Antenna-Patterns-Smith-2nd-1958.pdf

https://worldradiohistory.com/BOOKSHELF-ARH/Technology/Directional-Antenna-Patterns-Smith-2nd-1958.pdf

Renée,K6FSB

On 3/30/22 10:25 AM, Grant Saviers wrote:
> Thanks for an interesting article.
>
> I did a little reverse engineering from the KYW 1934 "4 square" 
> picture and commentary.  A figure 8 pattern was the objective.
>
> It seems to have used 8 radials elevated 10ft per tower.  The text 
> says "55,000 feet of wire" in radial "cages".  A little tough to tell 
> but I can resolve 3 or 4 wire cages.  For a frequency of 1020Khz and 
> 32 radials/4 wire cages that is roughly 1/8wl.  Or maybe ~3/8wl if 
> they are 3 wire cages.  A 200ft tall vertical. Whatever it was, they 
> could put 50Kw into it.
>
> The reference book of patterns for 2 and 3 element verticals is
> Directional Antennas, by Carl E. Smith, E.E., Cleveland Institute of 
> Radio Electronics, 1946
> and is available in pdf from scribd.com
>
> It has hundreds of fascinating patterns created by Carl Smith's analog 
> computer.  Antenna patterns for every possible need, if you have the 
> space and expertise to work out the feed.
>
> One comment in article had me wondering.  "The towers were fed by 
> individual transmission lines from a phasing circuit that separately 
> controlled the current and phase of each tower."
>
> The 4 square was replaced with two 450ft towers for "increased 
> radiation efficiency" in 1949 per 
> https://www.broadcastpioneers.com/kywstory.html
>
> Some pretty clever engineering by pioneers 88 years ago.
>
> Grant KZ1W
>
> On 3/29/2022 09:31, Radio KH6O wrote:
>> This article describes the history of the development of directional MF
>> antennas on our neighbor, the AM broadcast band.
>>
>> 73,
>> Jeff KH6O
>>
>> https://www.radioworld.com/columns-and-views/roots-of-radio/the-development-of-the-directional-am-broadcast-antenna?utm_source=SmartBrief&utm_medium=email&utm_campaign=0028F35E-226C-4B60-AC88-AB2831C8A639&utm_content=8E01A4B9-193C-4BAE-B25D-23D973D5E345&utm_term=5e35c2b9-3044-4235-9961-04d879406e09 
>>
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