I'll back off on my comment based on Geoff's EZNEC study, you may have issues with 30/40 dual elements.
I have used a single 40M element and remote switched in/out tuned network for matching. This did work well, but it's not as simple as a parallel feed. 73, Julius Julius Fazekas n2wn wrote: > > Hi Roy, > > There's no reason to cut resonant radials if they will be on the ground or > buried. You gain nothing and waste time and money. If they were raised > then you should do what you suggest. > > The radials should be dense near the base of the antenna, that is where > the current is highest and the ground lose is most profound. > > You're in an area that typically has better soil conditions than some of > us have. I suspect you could have a great signal with 30 to 36 radials, > versus 64 where you might only pick up a half dB. > > There have been a number of great studies published in QEX and NCJ in the > past couple of years. Well worth reading before hand. > > Rudy, N6LF, has posted his studies online at > http://www.antennasbyn6lf.com/design_of_radial_ground_systems/ > > Well worth reading to save time and effort. > > You should be able to do what you suggest with the ladder line. You may > have to trim the 30M element a few times, or better yet, tune it with a > cap at the base to bring it to resonance. > If you're an ARRL member search for: "An Efficient Multiband Vertical for > 160 through 20 Meters" which uses a similar approach. > > I use stranded 18 AWG for my radials and they work well. I know folks > using smaller gauge with higher power too. It just depends on how many and > how much traffic you have near them (from a mechanical perspective). > > Any vertical that is base loaded is the least efficient, stay away from > those if possible. I've been through this and the difference is like night > and day. > > Good luck with the build! > > 73, > Julius > > > Roy Davis wrote: >> >> I am in the process of building a 40 meter 1/4 wave vertical. My hopes >> for >> this antenna is that when the conditions favor vertical antennas as >> opposed >> to a dipole, that it will help me to work in to the far East as my dipole >> does not. I understand that a dense radial field is necessary for good >> results and that the far field which I have no control is a factor. My >> plan >> is to use 64 insulated radials as close to resonant as possible, buried a >> few inches below soil. I thought of using ladder line as the radiator, >> cutting one side for 40 and the other for 30 meters supported by a >> catenary >> line. If that does not prove out, I have aluminum tubing which to make a >> 1/4 wave for 40. Anyone have any comments pro or con for my project? So >> far, I have the pipe in the ground, and the radials cut ready to attach >> to >> the DX Engineering radial plate. >> >> I have K3 #1366 and really like this radio. A lot to offer in such a >> small >> package. >> >> 73. >> >> Roy Davis - WK4Y >> Richmond VA >> >> >> ----- Original Message ----- >> From: "WILLIS COOKE" <[email protected]> >> To: "James Apple" <[email protected]>; <[email protected]>; >> "Darwin, >> Keith" <[email protected]> >> Sent: Sunday, March 15, 2009 6:12 PM >> Subject: Re: [Elecraft] 43' Vertical and the K2 tuner >> >> >>> >>> Keith, in theory the 5/8 vertical should be 3 db stronger than the 1/4 >>> vertical installed in the same position. A ground plane on top of a >>> house >>> could easily be as good or better than a 5/8 wave ground mounted and >>> radiating into the side of the house and some trees. 3 db is about 1/2 >>> S >>> unit anyway, so it will not be a large difference. You are correct >>> about >>> the far field conductivity being very important in how a vertical >>> antenna >>> will play, whether it is mounted on top of a tower or house or ground >>> mounted. The radials are most important to bring up the radiation >>> efficiency, the far field is most important for the take off angle. >>> >>> The 43 foot vertical will have a higher radiation resistance than a >>> shorter vertical for all bands, making it easier to get the efficiency >>> up. >>> It will still be lower than 50 ohms for 160, 80 and 60 meters, about 50 >>> ohms for 40 and higher for the upper frequencies. I don't have one >>> because I have a 3 element SteppIR with the 30/40 dipole trombone at 21 >>> meters. I don't think the 43 foot vertical will play as well, but they >>> do >>> play well. I have worked several of the Zero-Five offering and they all >>> play well. I would expect the DXE, Hygain and MFJ to play well also, >>> but >>> they are newer and I don't know anyone who has one. All still need a >>> good >>> ground plane and will play much better with conductive soil. >>> >>> Willis 'Cookie' Cooke >>> K5EWJ >>> >>> >>> --- On Sun, 3/15/09, Darwin, Keith <[email protected]> wrote: >>> >>>> From: Darwin, Keith <[email protected]> >>>> Subject: Re: [Elecraft] 43' Vertical and the K2 tuner >>>> To: "James Apple" <[email protected]>, [email protected] >>>> Date: Sunday, March 15, 2009, 2:39 PM >>>> A few years ago, I was really on the 5/8 vertical bandwagon. >>>> I thought it was the cat's meow. The problem was that >>>> real world A/B testing did NOT show it to be any better than >>>> a 1/4 wave vert. >>>> >>>> I had a 5/8 wave vert for 15 meters. Ground mounted over >>>> 16 radials. An ATU at the base took care of the small >>>> impedance mismatch and RG-213 carried the signal to the rig. >>>> Hot stuff - or so I thought. >>>> >>>> I also had a 1/4 wave ground plane (4 radials) on the roof >>>> of my single story house. It was fed with RG-58. I spent a >>>> lot of time with an A/B switch listening to both antennas. >>>> You'd think the 5/8 with it's mondo low-angle >>>> radiation pattern would walk all over the 1/4 wave but it >>>> DID NOT. DX signals as the band was just opening or closing >>>> were sometimes stronger on the 5/8, other times on the 1/4. >>>> There was no clear winner. >>>> >>>> It was years before I found the answer. >>>> >>>> Apparently, that wonderful low angle radiation that we want >>>> out of the 5/8 wave antenna depends HEAVILY on the ground >>>> conductivity many, many wavelengths away from the antenna. >>>> Far out of the reach of any ground radial system, poor soil >>>> conductivity is sucking the low angle radiation down to near >>>> zero. Sure, over salt water it is fabulous, but for the >>>> vast majority, it just doesn't pan out that way. >>>> >>>> So, for "normal" soil, it seems the best height >>>> is something less than 1/2 wave. >>>> >>>> I run a 33' vertical with a Hustler 80M resonator on >>>> top. It resonates on 80 and 40 and does pretty well on >>>> those two bands. It also delivers the goods on 30 meters >>>> due to the remote tuner. On 20 meters and higher it >>>> isn't really all that impressive. >>>> >>>> - Keith N1AS - >>>> - K3 711 - >>>> >>>> >>>> -----Original Message----- >>>> From: [email protected] on behalf of James >>>> Apple >>>> Sent: Sun 3/15/2009 9:26 AM >>>> To: [email protected] >>>> Subject: [Elecraft] 43' Vertical and the K2 tuner >>>> >>>> After the ice storm of 2009, I'm looking for an new >>>> antenna. I've >>>> been considering the 43' verticals by DXE,HyGain and >>>> MFJ. But I'm not >>>> sure if my K2 tuner will have the range needed. The DXE >>>> site has a >>>> warning about internal tuners. Anyone using a K2 and a >>>> 43' vertical ? >>>> how's it play ? >>>> >>>> Thanks in Advance >>>> >>>> - Jim (WB1DOG) >>>> ______________________________________________________________ >>>> Elecraft mailing list >>>> Home: http://mailman.qth.net/mailman/listinfo/elecraft >>>> Help: http://mailman.qth.net/mmfaq.htm >>>> Post: mailto:[email protected] >>>> >>>> This list hosted by: http://www.qsl.net >>>> Please help support this email list: >>>> http://www.qsl.net/donate.html >>>> >>>> >>>> ______________________________________________________________ >>>> Elecraft mailing list >>>> Home: http://mailman.qth.net/mailman/listinfo/elecraft >>>> Help: http://mailman.qth.net/mmfaq.htm >>>> Post: mailto:[email protected] >>>> >>>> This list hosted by: http://www.qsl.net >>>> Please help support this email list: >>>> http://www.qsl.net/donate.html >>> ______________________________________________________________ >>> Elecraft mailing list >>> Home: http://mailman.qth.net/mailman/listinfo/elecraft >>> Help: http://mailman.qth.net/mmfaq.htm >>> Post: mailto:[email protected] >>> >>> This list hosted by: http://www.qsl.net >>> Please help support this email list: http://www.qsl.net/donate.html >> >> >> -------------------------------------------------------------------------------- >> >> >> >> No virus found in this incoming message. >> Checked by AVG - www.avg.com >> Version: 8.0.237 / Virus Database: 270.11.15/2003 - Release Date: >> 03/15/09 >> 14:07:00 >> >> ______________________________________________________________ >> Elecraft mailing list >> Home: http://mailman.qth.net/mailman/listinfo/elecraft >> Help: http://mailman.qth.net/mmfaq.htm >> Post: mailto:[email protected] >> >> This list hosted by: http://www.qsl.net >> Please help support this email list: http://www.qsl.net/donate.html >> >> > > ----- Julius Fazekas N2WN Tennessee Contest Group http://www.k4ro.net/tcg/index.html Tennessee QSO Party http://www.tnqp.org/ Elecraft K2/100 #4455 Elecraft K3/100 #366 -- View this message in context: http://n2.nabble.com/43%27-Vertical-and-the-K2-tuner-tp2481408p2486607.html Sent from the Elecraft mailing list archive at Nabble.com. ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
