Re: [Elecraft] OT: Antenna ideas for a cheap ham
Right. That makes sense. Though the worst case would be a 2:1 SWR if both are resonant, because the feed point impedance would be 1/2 what is expected. Not the end of the world. A 40m dipole isn’t quite resonant on 15m anyway, so having both might make for more broadband 15m behavior with fewer broadside nulls. The ARRL Handbook includes a design with capacitance stubs to fix the resonance on 15m. My setup is an 80/40/20 fan dipole with a neat trick. The 80m dipole is center loaded, and the center section is cut to resonate on 20m. In parallel with that is a full-sized 40m dipole. The loaded 80m element is just a few feet longer than the 40m element. That is the 3B2080LFAN from Hy Power Antennas. Good construction at a good price and a clever idea. http://www.hypowerantenna.com/products/fan-dipole Walter Underwood wun...@wunderwood.org http://observer.wunderwood.org/ On Sep 14, 2014, at 12:16 AM, Bill Frantz wrote: > Fan dipoles depend on the relatively high impedance on the fan pieces that > are for other bands to send most of the energy into the tuned fan. If you are > using fans for 40 and 15, the energy will be split between them on 15M which > isn't what you want. > > BTW - My combination of a 160M dipole commonly fed with an 80M inverted V at > 90 degrees to the 160M dipole works quite well on 15 meters. The cocoaNEC > model shows good performance with 4 major lobes arranged more or less in the > direction of the 160M wire. > > 73 Bill AE6JV > > On 9/13/14 at 11:14 PM, wun...@wunderwood.org (Walter Underwood) wrote: > >> Eh? A 40m dipole is pretty close to resonance on 15m already, so how can you >> avoid that. In fact, all dipoles are resonant at odd multiples of half >> waves, so this is impossible to avoid. >> >> Could you clarify the issue here? >> >> wunder >> K6WRU >> CM87wj >> http://observer.wunderwood.org/ >> >> On Sep 13, 2014, at 10:31 PM, Don Wilhelm wrote: >> >>> I failed to mention another point with regard to fan dipoles. Do not mix >>> 3rd harmonic radiators on >> the same coax. In other words, stay away from combinations of 40 meters and >> 15 meters, and also 40 meters and 30 meters. They may work, but tuning >> problems are 'iffy'. >>> >>> 73, >>> Don W3FPR >>> > --- > Bill Frantz| Since the IBM Selectric, keyboards have gotten > 408-356-8506 | steadily worse. Now we have touchscreen keyboards. > www.pwpconsult.com | Can we make something even worse? > > __ > 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 wun...@wunderwood.org __ 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
Re: [Elecraft] OT: Antenna ideas for a cheap ham
I use a cobweb at 40ft and it works real well for me also. It’s a good multiband antenna. ~73 Don KD8NNU 2014 Top Gun :-) -.- -.. ---.. -. -. ..- -Original Message- From: drewko Sent: Sunday, September 14, 2014 8:43 AM To: Elecraft@mailman.qth.net Subject: Re: [Elecraft] OT: Antenna ideas for a cheap ham I don't have a tower but I am using a 10-20m cobweb antenna in my attic. It's non-directional and feeds with a single coax. It gets out pretty well on all five bands. Recently worked aZL station on 17m with less than 2 watts (this is the requisite anecdotal information... but true.) I'd love to try it on an 80 ft tower... I'm using the G3TXQ version with single-wire elements. I originally trimmed it to freq using a (cheap) noise bridge but a graphical antenna analyzer would be nice and easy. 73, Drew AF2Z On Sat, 13 Sep 2014 13:16:37 -0800, you wrote: I sent this to the reflector last Tuesday but it never posted on the reflector; here it is again: Date: Tue, 09 Sep 2014 09:03:13 -0800 To: Elecraft Reflector From: Edward R Cole Subject: OT: Antenna ideas for a cheap ham This might be considered an offshoot of the OT R8 discussion - read on: A local ham friend dropped by to show my an antenna he had acquired wondering what freq. it covered. After looking it over I decided it was a 36-MHz quarter wave vertical with decoupling section at the base and fed with a gamma-match. The gamma has a 7/16 coax connector with N-female adapter, so apparently commercial band. My friend also recently acquired an 80-foot crank-up tower for $100 (Yes, you read that correctly). Some guys are really lucky! He lives on disability so has few funds for ham radio, but asks me what antennas he can put on top of his tower. He does not want a directional antenna like a yagi...sooo First we considered he could lengthen the 72-inch commercial vertical to operate on 10m and mount it on top of the tower. But that would only give him one band.He could also shorten it to 6m but there is little local activity on that band so 10m probably would provide him better use. For HF bands I thought about a dipole with auto-tuner. Finally thought maybe running sloping dipoles might work well. Base load that tower as grounded vertical? 160-40m? Another note: He has a tech-class license so that limits where he can operate. I suggested upgrading to General and he is not adverse to doing that. He owns a IC-706. Any suggestions? 73, Ed - KL7UW http://www.kl7uw.com "Kits made by KL7UW" Dubus Mag business: dubus...@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 gold...@charter.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 arch...@mail-archive.com
Re: [Elecraft] OT: Antenna ideas for a cheap ham
Thanks for the suggestions. We considered shortening the vertical from 36 to 50 MHz, but there is almost no local activity on 6m so probably of more use to him with a Tech License as a 10m vertical - just has to add aluminum tubing of the correct diameter (the antenna has existing section the slides for tuning and uses a metal hose clamp to secure). Some form of wire dipoles will be added, whether in inverted-V or maybe simply sloping in a desired direction and only needing a single rope to tie off to ground. Probably 20m & 15m. An 80/40m fan inverted-V could be hung with center at a lower point on the tower to be usable in NVIS mode. 45-60 foot high and being far below the 20-10m antennas would not interact. 80/40m dipole should be oriented for good N-S radiation to cover AK from our location on the Kenai Peninsula. I have a 80/40m invert-V at 45 foot with ends at 20-feet. I spaced the two wires using 8-inch painted wooden dowel spacers to keep even spacing and cut the 80m dipole first using an antenna analyzer. Then slight adjustment after the 40m dipole was cut. I get 3700-4000 and 7000-7250 without need for a tuner. Tuner permits running at 3500-3600 and 7200-7300. The man has few funds to spend on ham goodies so offering things he can make with materials in-hand. He says he has a lot of wire. Not sure on coax and how long the runs will be. Since cables would need to be suspended on a pilot rope or cable from top of the tower so the tower can be cranked up/down, a remote coax switch would be handy for him. Anyway have a good supply of ideas for him, now! 73, Ed - KL7UW http://www.kl7uw.com "Kits made by KL7UW" Dubus Mag business: dubus...@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
Re: [Elecraft] OT: Antenna ideas for a cheap ham
The reason that the 80/40/15 combo does not work well is that the 40 resonates pretty well on 15 because it is 3/4 wave. I have had a lot of difficulty with 80/40/20 and have never had one work well. My current fan is an Alpha-Delta 80/40 with a 75 meter wire fanned. It is the magic formula to use the same antenna for 80 CW and 75 Phone. It also works well with a tuner on 15 and nicely on 40. I have the apex at 44 feet and the fan about 20 degrees. It does not work well on 20 and 10 or the WARC bands. Willis 'Cookie' Cooke, TDXS DX Chairman K5EWJ & Trustee N5BPS, USS Cavalla, USS Stewart On Sunday, September 14, 2014 12:41 AM, Don Wilhelm wrote: I failed to mention another point with regard to fan dipoles. Do not mix 3rd harmonic radiators on the same coax. In other words, stay away from combinations of 40 meters and 15 meters, and also 40 meters and 30 meters. They may work, but tuning problems are 'iffy'. 73, Don W3FPR On 9/14/2014 1:08 AM, Jim Brown wrote: > On Sat,9/13/2014 5:01 PM, Don Wilhelm wrote: >> One other comment regarding fan dipoles. >> They really work well, but if one attempts to put more than 3 bands >> on a fan dipole, the interaction can become frustrating to tune them >> all, been there, done that, and have all the scars. > > Strongly agree. Also, fans work best on harmonically related bands. > 80/40 works very well, so does 20/15/10. 40/30/20 not so good. > > I use separations of about 9 inches for 20/15/10, and about 15 inches > for 80/40. > __ 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 wrco...@yahoo.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
Re: [Elecraft] OT: Antenna ideas for a cheap ham
Correction: Make that 'don't mix 80 meters and 30 meters on the same coax' 73, Don W3FPR --- I failed to mention another point with regard to fan dipoles. Do not mix 3rd harmonic radiators on the same coax. In other words, stay away from combinations of 40 meters and 15 meters, and also 40 meters and 30 meters. They may work, but tuning problems are 'iffy'. 73, Don W3FPR On 9/14/2014 1:08 AM, Jim Brown wrote: On Sat,9/13/2014 5:01 PM, Don Wilhelm wrote: One other comment regarding fan dipoles. They really work well, but if one attempts to put more than 3 bands on a fan dipole, the interaction can become frustrating to tune them all, been there, done that, and have all the scars. Strongly agree. Also, fans work best on harmonically related bands. 80/40 works very well, so does 20/15/10. 40/30/20 not so good. I use separations of about 9 inches for 20/15/10, and about 15 inches for 80/40. __ 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
Re: [Elecraft] OT: Antenna ideas for a cheap ham
I don't have a tower but I am using a 10-20m cobweb antenna in my attic. It's non-directional and feeds with a single coax. It gets out pretty well on all five bands. Recently worked aZL station on 17m with less than 2 watts (this is the requisite anecdotal information... but true.) I'd love to try it on an 80 ft tower... I'm using the G3TXQ version with single-wire elements. I originally trimmed it to freq using a (cheap) noise bridge but a graphical antenna analyzer would be nice and easy. 73, Drew AF2Z On Sat, 13 Sep 2014 13:16:37 -0800, you wrote: >I sent this to the reflector last Tuesday but it never posted on the >reflector; here it is again: > > >>Date: Tue, 09 Sep 2014 09:03:13 -0800 >>To: Elecraft Reflector >>From: Edward R Cole >>Subject: OT: Antenna ideas for a cheap ham >> >>This might be considered an offshoot of the OT R8 discussion - read on: >> >>A local ham friend dropped by to show my an antenna he had acquired >>wondering what freq. it covered. After looking it over I decided it >>was a 36-MHz quarter wave vertical with decoupling section at the >>base and fed with a gamma-match. The gamma has a 7/16 coax >>connector with N-female adapter, so apparently commercial band. >> >>My friend also recently acquired an 80-foot crank-up tower for $100 >>(Yes, you read that correctly). Some guys are really lucky! He >>lives on disability so has few funds for ham radio, but asks me what >>antennas he can put on top of his tower. He does not want a >>directional antenna like a yagi...sooo >> >>First we considered he could lengthen the 72-inch commercial >>vertical to operate on 10m and mount it on top of the tower. But >>that would only give him one band.He could also shorten it to 6m but >>there is little local activity on that band so 10m probably would >>provide him better use. >> >>For HF bands I thought about a dipole with auto-tuner. Finally >>thought maybe running sloping dipoles might work well. Base load >>that tower as grounded vertical? 160-40m? >> >>Another note: He has a tech-class license so that limits where he >>can operate. I suggested upgrading to General and he is not adverse >>to doing that. He owns a IC-706. >> >>Any suggestions? > >73, Ed - KL7UW >http://www.kl7uw.com > "Kits made by KL7UW" >Dubus Mag business: > dubus...@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
Re: [Elecraft] OT: Antenna ideas for a cheap ham
Don't overlook traps. My low band antenna is a double (fan?) dipole with 80 M traps in one leg for 160/80 and 40 M traps in the other leg for 60/40 coverage. It seems to work fine at about 55 feet. In an inverted V configuration, just install the legs at 90 degrees to each other for minimal interaction. I did this for a 40/80 double V which also worked great with the top at 40 feet. 73, Charlie k3ICH - Original Message - From: "Jim Wiley" To: ; Sent: Sunday, September 14, 2014 3:30 AM Subject: Re: [Elecraft] OT: Antenna ideas for a cheap ham Don - Did you mean 80 meters and 30 meters? 40 meters and 30 meters should be OK, even if the frequency separation is not optimal. - Jim, KL7CC On 9/13/2014 9:31 PM, Don Wilhelm wrote: I failed to mention another point with regard to fan dipoles. Do not mix 3rd harmonic radiators on the same coax. In other words, stay away from combinations of 40 meters and 15 meters, and also 40 meters and 30 meters. They may work, but tuning problems are 'iffy'. 73, Don W3FPR __ 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 pin...@erols.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
Re: [Elecraft] OT: Antenna ideas for a cheap ham
Don - Did you mean 80 meters and 30 meters? 40 meters and 30 meters should be OK, even if the frequency separation is not optimal. - Jim, KL7CC On 9/13/2014 9:31 PM, Don Wilhelm wrote: I failed to mention another point with regard to fan dipoles. Do not mix 3rd harmonic radiators on the same coax. In other words, stay away from combinations of 40 meters and 15 meters, and also 40 meters and 30 meters. They may work, but tuning problems are 'iffy'. 73, Don W3FPR __ 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
Re: [Elecraft] OT: Antenna ideas for a cheap ham
Fan dipoles depend on the relatively high impedance on the fan pieces that are for other bands to send most of the energy into the tuned fan. If you are using fans for 40 and 15, the energy will be split between them on 15M which isn't what you want. BTW - My combination of a 160M dipole commonly fed with an 80M inverted V at 90 degrees to the 160M dipole works quite well on 15 meters. The cocoaNEC model shows good performance with 4 major lobes arranged more or less in the direction of the 160M wire. 73 Bill AE6JV On 9/13/14 at 11:14 PM, wun...@wunderwood.org (Walter Underwood) wrote: Eh? A 40m dipole is pretty close to resonance on 15m already, so how can you avoid that. In fact, all dipoles are resonant at odd multiples of half waves, so this is impossible to avoid. Could you clarify the issue here? wunder K6WRU CM87wj http://observer.wunderwood.org/ On Sep 13, 2014, at 10:31 PM, Don Wilhelm wrote: I failed to mention another point with regard to fan dipoles. Do not mix 3rd harmonic radiators on the same coax. In other words, stay away from combinations of 40 meters and 15 meters, and also 40 meters and 30 meters. They may work, but tuning problems are 'iffy'. 73, Don W3FPR --- Bill Frantz| Since the IBM Selectric, keyboards have gotten 408-356-8506 | steadily worse. Now we have touchscreen keyboards. www.pwpconsult.com | Can we make something even worse? __ 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
Re: [Elecraft] OT: Antenna ideas for a cheap ham
Eh? A 40m dipole is pretty close to resonance on 15m already, so how can you avoid that. In fact, all dipoles are resonant at odd multiples of half waves, so this is impossible to avoid. Could you clarify the issue here? wunder K6WRU CM87wj http://observer.wunderwood.org/ On Sep 13, 2014, at 10:31 PM, Don Wilhelm wrote: > I failed to mention another point with regard to fan dipoles. Do not mix 3rd > harmonic radiators on the same coax. In other words, stay away from > combinations of 40 meters and 15 meters, and also 40 meters and 30 meters. > They may work, but tuning problems are 'iffy'. > > 73, > Don W3FPR > > On 9/14/2014 1:08 AM, Jim Brown wrote: >> On Sat,9/13/2014 5:01 PM, Don Wilhelm wrote: >>> One other comment regarding fan dipoles. >>> They really work well, but if one attempts to put more than 3 bands on a >>> fan dipole, the interaction can become frustrating to tune them all, been >>> there, done that, and have all the scars. >> >> Strongly agree. Also, fans work best on harmonically related bands. 80/40 >> works very well, so does 20/15/10. 40/30/20 not so good. >> >> I use separations of about 9 inches for 20/15/10, and about 15 inches for >> 80/40. >> > > __ > 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 wun...@wunderwood.org __ 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
Re: [Elecraft] OT: Antenna ideas for a cheap ham
I failed to mention another point with regard to fan dipoles. Do not mix 3rd harmonic radiators on the same coax. In other words, stay away from combinations of 40 meters and 15 meters, and also 40 meters and 30 meters. They may work, but tuning problems are 'iffy'. 73, Don W3FPR On 9/14/2014 1:08 AM, Jim Brown wrote: On Sat,9/13/2014 5:01 PM, Don Wilhelm wrote: One other comment regarding fan dipoles. They really work well, but if one attempts to put more than 3 bands on a fan dipole, the interaction can become frustrating to tune them all, been there, done that, and have all the scars. Strongly agree. Also, fans work best on harmonically related bands. 80/40 works very well, so does 20/15/10. 40/30/20 not so good. I use separations of about 9 inches for 20/15/10, and about 15 inches for 80/40. __ 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
Re: [Elecraft] OT: Antenna ideas for a cheap ham
On Sat,9/13/2014 5:01 PM, Don Wilhelm wrote: One other comment regarding fan dipoles. They really work well, but if one attempts to put more than 3 bands on a fan dipole, the interaction can become frustrating to tune them all, been there, done that, and have all the scars. Strongly agree. Also, fans work best on harmonically related bands. 80/40 works very well, so does 20/15/10. 40/30/20 not so good. I use separations of about 9 inches for 20/15/10, and about 15 inches for 80/40. A very high 20/15/10 fan will have Zo near 50 ohms, but an equally high 80/40 will be closer to 75-80 ohms, depending on what your ground is. I feed my high 80/40s with RG11. Mine are up 110 ft. On any fan, the longest dipole will have it's "normal" SWR bandwidth, while the SWR bandwidths of the shorter dipole(s) will be about half normal. That works great for 80, which is the widest band as a percentage of frequency, and 40M is relatively narrow. No problem on 20/15/10 either, because we tend to use the bottom half of 10M. 73, Jim K9YC __ 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
Re: [Elecraft] OT: Antenna ideas for a cheap ham
If he has a long coax run, he should consider a remote antenna switch. I have one to keep the coax in the house to the YL's tolerance level. If he can locate it close enough to the feed points, he may be able to avoid multiple common mode chokes. 73 Bill AE6JV On 9/13/14 at 4:47 PM, w3...@embarqmail.com (Don Wilhelm) wrote: Yes, he would have to have an antenna switch to switch between the 3 coax feedlines, but that would give him 80 through 10 meter coverage. The 36 MHz antenna could be trimmed to 6 meters and added as a vertical on the tower for 80 through 6 meter coverage with 4 feedlines. For 160 meter coverage, run radials out from the tower and run it as a shunt fed vertical - yes, that probably is a 5th feedline, so use a 6 position coax switch and connect the 6th position to a dummy load to protect the equipment when it is not in use. He would not have to put up the WARC antennas until he has his General ticket. Other than the feedlines, the cost is as low as the wire used for the radiators and the baluns for each feedline. --- Bill Frantz| If the site is supported by | Periwinkle (408)356-8506 | ads, you are the product.| 16345 Englewood Ave www.pwpconsult.com | | Los Gatos, CA 95032 __ 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
Re: [Elecraft] OT: Antenna ideas for a cheap ham
One other comment regarding fan dipoles. They really work well, but if one attempts to put more than 3 bands on a fan dipole, the interaction can become frustrating to tune them all, been there, done that, and have all the scars. I separate the radiators in my fan dipoles by about 1 foot using PVC for the separators. It is important for the ends to be separated, but I like to begin the separation as close to the feedpoint as is practical. Cut the dipoles a bit long and tune them from the lowest band first to the highest band last to minimize the effects of interaction. Yes, I have successfully tuned a 6 band version of a fan dipole for a local ham, but it becomes a bit more of a challenge when going beyond 3 bands. 73, Don W3FPR --- Ed, Since he does not want a beam, I would suggest 3 dipole antennas supported from his 80 ft. tower - OK, really 8 dipoles, but 3 feedlines. All of them would be inverted VEE type. One of them is a fan dipole for 10/15/20 meters. Position that one to favor his preferred DX locations. The next is a fan dipole for the WARC bands 30/17/12 - position that one at 90 degrees to the 10/15/20 dipole. The third is a broadband antenna for 80 and 40. See the ARRL Antenna Book 19th Edition (may also be in later versions) page 9-16 - "A Simple Broadband Dipole for 80 Meters". It was initially described in a QST article in September 1993. It uses a 1 wavelength of RG-213 plus a 1/4 wavelength of RG-11 to produce a Transmission Line Resonator and will result in a 'double humped' SWR curve giving less than a 2:1 SWR from 3.5 MHz to 3.950 if the 80 meter wire is trimmed properly. A set of 40 meter wires can be added to this same coax giving both 80 and 40 meter coverage with a low SWR. Position the 4 radiator wires for this antenna at 45 degrees to the wires for the 10/15/20 meter and the 30/17/12 meter sets for minimum interaction. Yes, he would have to have an antenna switch to switch between the 3 coax feedlines, but that would give him 80 through 10 meter coverage. The 36 MHz antenna could be trimmed to 6 meters and added as a vertical on the tower for 80 through 6 meter coverage with 4 feedlines. For 160 meter coverage, run radials out from the tower and run it as a shunt fed vertical - yes, that probably is a 5th feedline, so use a 6 position coax switch and connect the 6th position to a dummy load to protect the equipment when it is not in use. He would not have to put up the WARC antennas until he has his General ticket. Other than the feedlines, the cost is as low as the wire used for the radiators and the baluns for each feedline. 73, Don W3FPR Date: Tue, 09 Sep 2014 09:03:13 -0800 To: Elecraft Reflector From: Edward R Cole Subject: OT: Antenna ideas for a cheap ham This might be considered an offshoot of the OT R8 discussion - read on: A local ham friend dropped by to show my an antenna he had acquired wondering what freq. it covered. After looking it over I decided it was a 36-MHz quarter wave vertical with decoupling section at the base and fed with a gamma-match. The gamma has a 7/16 coax connector with N-female adapter, so apparently commercial band. My friend also recently acquired an 80-foot crank-up tower for $100 (Yes, you read that correctly). Some guys are really lucky! He lives on disability so has few funds for ham radio, but asks me what antennas he can put on top of his tower. He does not want a directional antenna like a yagi...sooo First we considered he could lengthen the 72-inch commercial vertical to operate on 10m and mount it on top of the tower. But that would only give him one band.He could also shorten it to 6m but there is little local activity on that band so 10m probably would provide him better use. For HF bands I thought about a dipole with auto-tuner. Finally thought maybe running sloping dipoles might work well. Base load that tower as grounded vertical? 160-40m? Another note: He has a tech-class license so that limits where he can operate. I suggested upgrading to General and he is not adverse to doing that. He owns a IC-706. Any suggestions? __ 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
Re: [Elecraft] OT: Antenna ideas for a cheap ham
Ed, Since he does not want a beam, I would suggest 3 dipole antennas supported from his 80 ft. tower - OK, really 8 dipoles, but 3 feedlines. All of them would be inverted VEE type. One of them is a fan dipole for 10/15/20 meters. Position that one to favor his preferred DX locations. The next is a fan dipole for the WARC bands 30/17/12 - position that one at 90 degrees to the 10/15/20 dipole. The third is a broadband antenna for 80 and 40. See the ARRL Antenna Book 19th Edition (may also be in later versions) page 9-16 - "A Simple Broadband Dipole for 80 Meters". It was initially described in a QST article in September 1993. It uses a 1 wavelength of RG-213 plus a 1/4 wavelength of RG-11 to produce a Transmission Line Resonator and will result in a 'double humped' SWR curve giving less than a 2:1 SWR from 3.5 MHz to 3.950 if the 80 meter wire is trimmed properly. A set of 40 meter wires can be added to this same coax giving both 80 and 40 meter coverage with a low SWR. Position the 4 radiator wires for this antenna at 45 degrees to the wires for the 10/15/20 meter and the 30/17/12 meter sets for minimum interaction. Yes, he would have to have an antenna switch to switch between the 3 coax feedlines, but that would give him 80 through 10 meter coverage. The 36 MHz antenna could be trimmed to 6 meters and added as a vertical on the tower for 80 through 6 meter coverage with 4 feedlines. For 160 meter coverage, run radials out from the tower and run it as a shunt fed vertical - yes, that probably is a 5th feedline, so use a 6 position coax switch and connect the 6th position to a dummy load to protect the equipment when it is not in use. He would not have to put up the WARC antennas until he has his General ticket. Other than the feedlines, the cost is as low as the wire used for the radiators and the baluns for each feedline. 73, Don W3FPR Date: Tue, 09 Sep 2014 09:03:13 -0800 To: Elecraft Reflector From: Edward R Cole Subject: OT: Antenna ideas for a cheap ham This might be considered an offshoot of the OT R8 discussion - read on: A local ham friend dropped by to show my an antenna he had acquired wondering what freq. it covered. After looking it over I decided it was a 36-MHz quarter wave vertical with decoupling section at the base and fed with a gamma-match. The gamma has a 7/16 coax connector with N-female adapter, so apparently commercial band. My friend also recently acquired an 80-foot crank-up tower for $100 (Yes, you read that correctly). Some guys are really lucky! He lives on disability so has few funds for ham radio, but asks me what antennas he can put on top of his tower. He does not want a directional antenna like a yagi...sooo First we considered he could lengthen the 72-inch commercial vertical to operate on 10m and mount it on top of the tower. But that would only give him one band.He could also shorten it to 6m but there is little local activity on that band so 10m probably would provide him better use. For HF bands I thought about a dipole with auto-tuner. Finally thought maybe running sloping dipoles might work well. Base load that tower as grounded vertical? 160-40m? Another note: He has a tech-class license so that limits where he can operate. I suggested upgrading to General and he is not adverse to doing that. He owns a IC-706. Any suggestions? __ 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
[Elecraft] OT: Antenna ideas for a cheap ham
I sent this to the reflector last Tuesday but it never posted on the reflector; here it is again: Date: Tue, 09 Sep 2014 09:03:13 -0800 To: Elecraft Reflector From: Edward R Cole Subject: OT: Antenna ideas for a cheap ham This might be considered an offshoot of the OT R8 discussion - read on: A local ham friend dropped by to show my an antenna he had acquired wondering what freq. it covered. After looking it over I decided it was a 36-MHz quarter wave vertical with decoupling section at the base and fed with a gamma-match. The gamma has a 7/16 coax connector with N-female adapter, so apparently commercial band. My friend also recently acquired an 80-foot crank-up tower for $100 (Yes, you read that correctly). Some guys are really lucky! He lives on disability so has few funds for ham radio, but asks me what antennas he can put on top of his tower. He does not want a directional antenna like a yagi...sooo First we considered he could lengthen the 72-inch commercial vertical to operate on 10m and mount it on top of the tower. But that would only give him one band.He could also shorten it to 6m but there is little local activity on that band so 10m probably would provide him better use. For HF bands I thought about a dipole with auto-tuner. Finally thought maybe running sloping dipoles might work well. Base load that tower as grounded vertical? 160-40m? Another note: He has a tech-class license so that limits where he can operate. I suggested upgrading to General and he is not adverse to doing that. He owns a IC-706. Any suggestions? 73, Ed - KL7UW http://www.kl7uw.com "Kits made by KL7UW" Dubus Mag business: dubus...@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
