The broadcasters also dont fall for the resonance bit either; very few radiators plus radials have anything to do with an actual resonance. All of this was explained back in the 30's.
Carl KM1H ----- Original Message ----- From: "Milt -- N5IA" <n...@zia-connection.com> To: "Eddy Swynar" <deswy...@xplornet.ca>; <he...@vitelcom.net> Cc: <topband@contesting.com> Sent: Friday, February 10, 2012 12:11 PM Subject: Re: Topband: Radials help > HMMMMM!!!!!!!! > > If that is the case, WHY do the pro broadcasters install all 120 radials > at > full length; even bare wire buried a couple of inches underground? > > Inquiring minds want to know where this conversation is going. > > I understand that when you are doing radials, with a few they are part of > the resonance factor for the vertical. > > However, after a dozen or so radials are installed the length does NOT > necessarily determine resonance as the FIELD of "radials" becomes a > composite Ground Plane. > > Bigger Ground Planes are Better!!!!!! Think salt water. > > So, IMHO, the 1/4 WL radius from the vertical is most likely at the break > point for "return vs cost". And the more Ground Plane you can place in > that > 1/2 WL diameter circle, the more efficient your vertical will be. > > If I was installing insulated "radials" I would make them full 1/4 WL > regardless of the VF. It just makes good engineering sense. > > I am still learning, so if I am incorrect in any of these items please > enlighten me. > > Mis dos centavos. > > 73 de Milt, N5IA > > > -----Original Message----- > From: Eddy Swynar > Sent: Friday, February 10, 2012 9:48 AM > To: he...@vitelcom.net > Cc: topband@contesting.com > Subject: Re: Topband: Radials help > > > On 2012-02-10, at 11:34 AM, Herb Schoenbohm wrote: > >> One advantage of using insulate wire is that the velocity factor of the >> wire >> on ground or (ROG) allows for shorter lengths. This is important if you >> have limited yard space. > > > > Hi Herb, > > Interesting point...! > > According to either the ARRL "ANTENNA HANDBOOK", or ON4UN's "LOW-BAND DX > HANDBOOK", the velocity factor of insulated wire placed atop the ground is > 50%... > > I take that to mean that a 1/8-wave PHYSICALLY long wire radial has the > ELECTRICAL equivalency of a wire radial that is 1/4-wave long... > > Maybe THAT'S the reason why I employ a total of 24 insulated radial wires, > 65' long (each) beneath my "L" elements...it may not be an "exact > science", > but hope springs eternal...! (Besides, have you seen the price of copper > wire lately...?!). : >) > > ~73~ de Eddy VE3CUI - VE3XZ > _______________________________________________ > UR RST IS ... ... ..9 QSB QSB - hw? BK > > > ----- > No virus found in this message. > Checked by AVG - www.avg.com > Version: 2012.0.1913 / Virus Database: 2112/4801 - Release Date: 02/10/12 > > _______________________________________________ > UR RST IS ... ... ..9 QSB QSB - hw? BK > > > ----- > No virus found in this message. > Checked by AVG - www.avg.com > Version: 10.0.1424 / Virus Database: 2112/4801 - Release Date: 02/10/12 > _______________________________________________ UR RST IS ... ... ..9 QSB QSB - hw? BK