<br><br>
<div class="gmail_quote">---------- Forwarded message ----------<br>From: <b class="gmail_sendername">Antonio Matias</b> <span dir="ltr"><<a href="mailto:ct1ffu@gmail.com">ct1ffu@gmail.com</a>></span><br>Date: 2012/10/11<br>
Subject: Re: [CT-Com. & Tec.] LFA ou DK7ZB ?<br>To: <a href="mailto:ct-comunicacoes-e-tecnologias@googlegroups.com">ct-comunicacoes-e-tecnologias@googlegroups.com</a><br><br><br>Não.
<div>na realidade as LFA não ficam nada bem na foto.</div>
<div><br></div>
<div>
<div style="FONT-FAMILY:'Times New Roman';FONT-SIZE:medium" align="center">
<center>
<table border="0" width="875">
<tbody>
<tr>
<td width="452"><font face="Arial, Arial, Helvetica"><img border="0" src="http://www.qsl.net/d/dk7zb/6m/512-ver+hor.gif" width="450" height="433"></font></td>
<td width="409"><font face="Arial, Arial, Helvetica"><b>In the last time it comes into fashion to compare "old" and "new" designs by other designers. Normally I would not share this discussion, but in this case I must make an exception.</b>
<p><b>G0KSC claims his 1-lambda 50-MHz-LFA as much better. Indeed the LFA has a greater bandwidth (which you do not need for CW/SSB/beacons). The LFA has a better pattern ("Low-Noise"), especially the bigger vertical sidelobes of the DK7ZB-Yagi are criticized.</b></p>
<p><b>But in the real world you have not free-space conditions. If you mount the Yagi above real ground, the sidelobe disappears by ground reflection influence (see picture down). Do you believe the upper sidelobe, pointed into the sky receives any "mystic" noise (from aliens, or what)? Or the horizontal forward sidelobe with is suppressed -25 dB?</b></p>
<p><b>Now compare the gain of the two Yagis with the same boomlength:</b></p></font>
<p align="center"><font face="Arial, Arial, Helvetica"><b><font color="#ff0000" size="4">5-El.-DK7ZB 9,6 dBd, 5-El.-LFA 8,9 dB</font></b></font></p></td></tr></tbody></table><font face="Arial, Arial, Helvetica"></font></center>
<font face="Arial, Arial, Helvetica"></font></div><font style="FONT-SIZE:medium" face="Arial, Arial, Helvetica"></font>
<div style="FONT-FAMILY:'Times New Roman';FONT-SIZE:medium" align="center"><font face="Arial, Arial, Helvetica"></font>
<center><font face="Arial, Arial, Helvetica"></font>
<table border="0" width="875">
<tbody>
<tr>
<td width="452"><font face="Arial, Arial, Helvetica"><b>In the real environment you cannot see anything from a sidelobe pointed downwards !</b>
<p><b>But a difference of 0,7 dB gain for the same boomlength of 1 lambda is a really big one.</b></p>
<p><b>22 years of my own DX-experience on 6 m show the effectivity of high-gain Yagis. The simple to built 5-El.-Yagi is still a good choice!</b></p></font><br></td>
<td width="409"><font face="Arial, Arial, Helvetica"><img border="0" src="http://www.qsl.net/d/dk7zb/6m/512-elevation.gif" width="500" height="278"></font></td></tr></tbody></table></center></div><br>
<div class="gmail_quote">No dia 11 de Outubro de 2012 13:48, Filipe Lopes <span dir="ltr"><<a href="mailto:ct1ilt@gmail.com" target="_blank">ct1ilt@gmail.com</a>></span> escreveu:<br>
<blockquote style="BORDER-LEFT:#ccc 1px solid;MARGIN:0px 0px 0px 0.8ex;PADDING-LEFT:1ex" class="gmail_quote"><font color="#000000"><font size="+0"><font face="georgia,serif">Cheira-me que este site foi feito por algum "amigo" do Justin...<br>
<br>FL<br>CT1ILT<br></font></font></font><br>
<div class="gmail_quote">2012/10/11 Antonio Matias <span dir="ltr"><<a href="mailto:ct1ffu@gmail.com" target="_blank">ct1ffu@gmail.com</a>></span><br>
<blockquote style="BORDER-LEFT:#ccc 1px solid;MARGIN:0px 0px 0px 0.8ex;PADDING-LEFT:1ex" class="gmail_quote">
<div>
<div>Interessante site, onde ambos os desenhos são analisados.
<div>Será que a LFA é assim tão melhor em relação ás yagis convencionais?</div>
<div>Vai ter uma surpresa.</div>
<div><br></div>
<div><a href="http://www.rwpenfold.co.cc/" target="_blank">http://www.rwpenfold.co.cc/</a></div>
<div>
<h1 style="MARGIN:1em 0px 0.5em;FONT-FAMILY:Georgia,'Times New Roman',Times,serif;FONT-SIZE:1.35em">Antenna Engineer Investigates G0KSC's LFA Loop Fed Array & DK7ZB's Yagis</h1>
<h2 style="LINE-HEIGHT:1.4;MARGIN:0px 0px 2px;FONT-FAMILY:Georgia,'Times New Roman',Times,serif;COLOR:rgb(59,59,59);FONT-SIZE:1.42em;PADDING-TOP:0.5em">Science, it's matter of opinion!</h2>
<p style="LINE-HEIGHT:22px;MARGIN:0px 0px 1.2em;FONT-FAMILY:Georgia,'Times New Roman',Times,serif;COLOR:rgb(59,59,59);FONT-SIZE:14px"><br></p>
<p style="LINE-HEIGHT:22px;MARGIN:0px 0px 1.2em;FONT-FAMILY:Georgia,'Times New Roman',Times,serif;COLOR:rgb(59,59,59);FONT-SIZE:14px">My name is RW, I'm a retired <b>Telecommunications/Antenna Engineer</b> </p>
<p style="LINE-HEIGHT:22px;MARGIN:0px 0px 1.2em;FONT-FAMILY:Georgia,'Times New Roman',Times,serif;COLOR:rgb(59,59,59);FONT-SIZE:14px">with over 50 years industry experience and for my hobby now enjoy </p>
<p style="LINE-HEIGHT:22px;MARGIN:0px 0px 1.2em;FONT-FAMILY:Georgia,'Times New Roman',Times,serif;COLOR:rgb(59,59,59);FONT-SIZE:14px">Short Wave Listening and travelling across the globe!</p>
<p style="LINE-HEIGHT:22px;MARGIN:0px 0px 1.2em;FONT-FAMILY:Georgia,'Times New Roman',Times,serif;COLOR:rgb(59,59,59);FONT-SIZE:14px"><img style="BORDER-BOTTOM: 0px; BORDER-LEFT: 0px; OUTLINE-STYLE: none; OUTLINE-COLOR: invert; OUTLINE-WIDTH: 0px; BORDER-TOP: 0px; BORDER-RIGHT: 0px" title="" alt="" src="http://www.rwpenfold.co.cc/PICS/anechoic-chamber.gif"></p>
<div><br clear="all">
<div><br></div>-- <br>António Matias
<div><br></div>
<div>CT1FFU - CR5A </div>
<div><br></div>
<div><a href="http://www.dxpatrol.com/" target="_blank">www.dxpatrol.com</a> </div>
<div><br></div>
<div>QRV: HF, 6m, 4m,2m,70cm,23cm</div>
<div>SSB, CW, MGM</div>
<div>DX, EME, Contest,Sat.</div>
<div><br></div>
<div>POBOX-38</div>
<div>2504-909</div>
<div>Caldas da Rainha</div>
<div>Portugal</div><span><font color="#888888"><br></font></span></div></div></div></div><span><font color="#888888">
<p></p>-- <br>Para mais informações/opções visite o site, e edite a sua conta:<br><a href="http://groups.google.com/group/ct-comunicacoes-e-tecnologias?hl=en?hl=pt-PT" target="_blank">http://groups.google.com/group/ct-comunicacoes-e-tecnologias?hl=en?hl=pt-PT</a><span><font color="#888888"><br>
</font></span></font></span></blockquote></div><span><font color="#888888"><br><br clear="all"><br>-- <br><font style="FONT-FAMILY:georgia,serif">Regards/Cumprimentos,<br>Filipe Lopes CT1ILT aka CR6K<br><a href="http://www.rep.pt/ct1ilt" target="_blank">http://www.rep.pt/ct1ilt</a></font><br style="FONT-FAMILY:georgia,serif">
<br><br>
<p></p>-- <br>Para mais informações/opções visite o site, e edite a sua conta:<br><a href="http://groups.google.com/group/ct-comunicacoes-e-tecnologias?hl=en?hl=pt-PT" target="_blank">http://groups.google.com/group/ct-comunicacoes-e-tecnologias?hl=en?hl=pt-PT</a><br>
</font></span></blockquote></div><br><br clear="all">
<div><br></div>-- <br>António Matias
<div><br></div>
<div>CT1FFU - CR5A </div>
<div><br></div>
<div><a href="http://www.dxpatrol.com/" target="_blank">www.dxpatrol.com</a> </div>
<div><br></div>
<div>QRV: HF, 6m, 4m,2m,70cm,23cm</div>
<div>SSB, CW, MGM</div>
<div>DX, EME, Contest,Sat.</div>
<div><br></div>
<div>POBOX-38</div>
<div>2504-909</div>
<div>Caldas da Rainha</div>
<div>Portugal</div><span class="HOEnZb"><font color="#888888"><br></font></span></div><span class="HOEnZb"><font color="#888888">
<p></p>-- <br>Para mais informações/opções visite o site, e edite a sua conta:<br><a href="http://groups.google.com/group/ct-comunicacoes-e-tecnologias?hl=en?hl=pt-PT" target="_blank">http://groups.google.com/group/ct-comunicacoes-e-tecnologias?hl=en?hl=pt-PT</a><br>
</font></span></div><br>