For a similar 10M version, look at N1LO's 10M Wire Collinear Super J-Pole which you can find at Nylo's Notepad Antenna Page. I have built and installed several of these vertical antennas over the years, hanging from tall tree limbs and stacked telescopic fiberglass poles. My EZNEC model shows omni gain of 4.34dbi at 9 degrees with top wire end at 52 ft.
73, Henry - K4TMC On Thu, Sep 29, 2022 at 3:31 PM Fred Jensen <k6dg...@gmail.com> wrote: > The Franklin is two vertical, co-linear half-waves fed in-phase. Google > will offer way more than you want to read. Obviously a large structural > challenge for a full-size one at MF. The one I built as a test was > heavily loaded and worked about like EZNEC-4 predicted. I think it's > insensitivity to "ground" may be one reason it works well, but that's > just a guess. > > > 73, > > Fred ["Skip"] K6DGW > Sparks NV DM09dn > Washoe County > > Dan Presley wrote on 9/29/2022 12:20 PM: > > Fred-can you share details on this antenna? Not familiar with it. Thanks. > > > > Dan Presley 503-701-3871 > > danpresley@me. com > > n7...@arrl.net > > > > > >> On Sep 29, 2022, at 12:08, Fred Jensen<k6dg...@gmail.com> wrote: > >> > >> I've long wondered why hams haven't done more with Franklin > verticals? KFBK [1530 kHz in Sacramento] uses one located in the southern > end of the Sacramento Valley, and it's known as a Flame Thrower. I think > KNBC [680 kHz?] in SF had one back in the 50's sometime too. They're big > at MF, but much more tractable at HF, and they are amenable to loading > techniques. I built one [fairly heavily loaded] out of Buddipole parts I > had, and its performance, particularly when I was still activating summits, > was surprising. Like a small loop, the Franklin pretty much ignores ground > ... although KFBK's probably likes being located in rice fields filled with > water. 😉 > >> > >> 73, > >> > >> Fred ["Skip"] K6DGW > >> Sparks NV DM09dn > >> Washoe County > >> > >> Jim Brown wrote on 9/29/2022 11:28 AM: > >>> David, > >>> > >>> I've published a LOT of work on concepts like this. > >>> > >>> This ran in National Contest Journal about six years ago. It's based > on extensive modeling, and was peer reviewed. > >>> > >>> http://k9yc.com/AntennaPlanning.pdf > >>> > >>> This was added to the ARRL Handbook or Antenna Book several years ago. > >>> > >>> http://k9yc.com/VerticalDipole.pdf > >>> > >>> This is an application of the above technique. > >>> > >>> http://k9yc.com/80M-FDVertical.pdf > >>> > >>> N6BT (original Force 12) has done a lot designs for monoband and > multiband verticals that are loaded dipoles. The multiband Cushcraft > R-series and Hi-Gain AV-series multiband verticals (companies bought out by > MFJ many years ago) are loaded dipoles. > >>> > >>> 73, Jim K9YC > >>> > >>>> On 9/29/2022 11:09 AM, David Gilbert wrote: > >>>> > >>>> You're talking about a horizontal pair of AX1's ... I asked about > them oriented vertically. That wouldn't require them to be as high above > ground as you mention and would still allow them to be carried pedestrian > mobile. > >> -- > >> This email has been checked for viruses by AVG antivirus software. > >> www.avg.com > >> ______________________________________________________________ > >> Elecraft mailing list > >> Home:http://mailman.qth.net/mailman/listinfo/elecraft > >> Help:http://mailman.qth.net/mmfaq.htm > >> Post:mailto:Elecraft@mailman.qth.net > >> > >> This list hosted by:http://www.qsl.net > >> Please help support this email list:http://www.qsl.net/donate.html > >> Message delivered ton7...@arrl.net > > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:Elecraft@mailman.qth.net > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to kilo4...@gmail.com ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
