For those interested in 630 meter , I use a 60 ft vertical.Photo on qrz dot com
73 Ken K5DNL/ WG2XXM ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
N6LF's website should be required reading for anyone intending to
operate these new bands. He's done extensive work on antenna systems for these bands. 73, Jim K9YC On 9/19/2017 10:39 AM, Ken Roberson via Elecraft wrote: > For those interested in 630 meter , I use a 60 ft vertical.Photo on qrz dot com > ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
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N6LF is also WD2XSH/20 whose 630m CW signal I copied up here. Rudy
moved a couple years ago to new property and has new antenna farm. I believe his study of elevated grounds was published in QEX and later in QST. Virtually all transmitting antenna for 630m will be "short" verticals so his findings are useful if you consider getting on 630m. EZNEC-5 indicated my radiation resistance would only be 0.83 ohms with a 43-foot high top-loaded vertical. Actual measurement showed 18 ohms so efficiency is 0.83/18 = 0.046. My ground plane is woefully too small: four 70-foot by 2-foot wide runs of chicken wire on ground. But most hams have too little acreage for anything even close to 1/4 WL (521-foot). My antenna consists of three parallel vertical wires spaced 1-foot apart and shorted by a 1/2 inch copper tube at both top and bottom; horizontal leg is two parallel wires spaced 2-foot and 122-foot long (like-wise with copper tube shorting bars). The parallel wires lower Q a bit to widen the SWR bandwidth which is about 5-KHz. Extra horizontal wire increases top-hat capacitance which makes vertical look longer. I will make a new webpage to show what I am using on 630m (old webpage was hacked several years ago and I never resurrected the 600m page). I may still get my inverted-L repaired and rehung with aid of my prof. tower person, though winter wx is not far off up here (freezing temps expected within a week). 73, Ed - KL7UW I will probably play with running WSPR and the new FT8 digital modes on 630m. Date: Tue, 19 Sep 2017 11:09:10 -0700 From: Jim Brown <[hidden email]> To: [hidden email] Subject: Re: [Elecraft] 630M Antenna Message-ID: <[hidden email]> Content-Type: text/plain; charset=utf-8; format=flowed N6LF's website should be required reading for anyone intending to operate these new bands. He's done extensive work on antenna systems for these bands. 73, Jim K9YC 73, Ed - KL7UW http://www.kl7uw.com Dubus-NA Business mail: [hidden email] ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
>
> But most hams have too little acreage for anything even close to 1/4 WL > (521-foot). The height restriction is 60 m (~197 ft). 73 de AI6KG On Wed, Sep 20, 2017 at 9:19 AM, Edward R Cole <[hidden email]> wrote: > N6LF is also WD2XSH/20 whose 630m CW signal I copied up here. Rudy moved > a couple years ago to new property and has new antenna farm. > I believe his study of elevated grounds was published in QEX and later in > QST. > > Virtually all transmitting antenna for 630m will be "short" verticals so > his findings are useful if you consider getting on 630m. EZNEC-5 indicated > my radiation resistance would only be 0.83 ohms with a 43-foot high > top-loaded vertical. Actual measurement showed 18 ohms so efficiency is > 0.83/18 = 0.046. My ground plane is woefully too small: four 70-foot by > 2-foot wide runs of chicken wire on ground. But most hams have too little > acreage for anything even close to 1/4 WL (521-foot). > > My antenna consists of three parallel vertical wires spaced 1-foot apart > and shorted by a 1/2 inch copper tube at both top and bottom; horizontal > leg is two parallel wires spaced 2-foot and 122-foot long (like-wise with > copper tube shorting bars). The parallel wires lower Q a bit to widen the > SWR bandwidth which is about 5-KHz. Extra horizontal wire increases > top-hat capacitance which makes vertical look longer. > > I will make a new webpage to show what I am using on 630m (old webpage was > hacked several years ago and I never resurrected the 600m page). > > I may still get my inverted-L repaired and rehung with aid of my prof. > tower person, though winter wx is not far off up here (freezing temps > expected within a week). > > 73, Ed - KL7UW > I will probably play with running WSPR and the new FT8 digital modes on > 630m. > > Date: Tue, 19 Sep 2017 11:09:10 -0700 > From: Jim Brown <[hidden email]> > To: [hidden email] > Subject: Re: [Elecraft] 630M Antenna > Message-ID: > <[hidden email]> > Content-Type: text/plain; charset=utf-8; format=flowed > > N6LF's website should be required reading for anyone intending to > operate these new bands. He's done extensive work on antenna systems for > these bands. > > 73, Jim K9YC > > > 73, Ed - KL7UW > http://www.kl7uw.com > Dubus-NA Business mail: > [hidden email] > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[hidden email] > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to [hidden email] > Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
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