[Antennas] Antenna Design Help Please

2002年1月23日 20:47:27 -0800

I am in no way knowledgeable about antennas. But I have been reading 
alot. I shall have to save up some money and by one of those modellers to 
try some of this one. Understand tha t learning how to use one is a challenge.
Having said that, what yoou have describes sounds a lot like a folded 
unipole by Paul Lee, N6PL.
Chris opr VE7HCB
At 09:32 AM 2002年01月23日 -0800, Nathan, Kevin wrote:
>Hi All,
>>I am still working on getting something that works well over the entire 160
>meter band. I have a design in mind but, being blind, can't use EZNEC to
>model it. So, would one of you gurus on here please model the following for
>me if you have the time and let me know what you find. Please send private
>replies to this address and cc to [email protected].
>>I have in mind to build a folded Marconi. Let's start with 130 feet of 450
>ohm windowed ladder line. Short one end together and call this the
>insulator end. Now, let's put this up as an inverted L with about 45 feet
>of it vertical and the rest horizontal sloping to approximately 20 feet at
>the end. At ground level, feed one side with the coax center conductor and
>the other side with the shield. Attach at least one above ground, quarter
>wave counterpoise to this shield connection. I would like to see what kind
>of characteristics this antenna would exhibit. Next, using more classic
>design, let's come back 7.5 feet from the insulator end (in other words,
>123.5 feet out from the feed point) and short the line together thus leaving
>the equivalent of a single wire for the remaining 7.5 physical feet. Does
>this change the characteristics of the antenna greatly?
>>I would really appreciate any information anyone could give me as to how
>this models. I have used similar antennas in the past made from 300 ohm
>twin lead but not ladder line.
>>Thanks in advance for your help. 73
>Kevin, K7RX