Re: [Elecraft] Vertical antennas Was: KX3 and KPA1500, compatibility
Ed, There is a FAR better way. Check out the design by VK4YB on his QRZ page. It's a brilliant design, and works great, enabling him to set the distance record on the band (in 2017, I think). The key element of the design are dimensions that carefully place the current maxima in the 120 ft vertical section, and that doesn't need a radial system. It's a VERY efficient antenna! BTW -- my NEC model didn't show pronounced directivity in the direction of the loading wire that the author observed. I took this as the starting point and tweaked the loading section to fit on W6GJB's property, supported by redwoods. My tweaks were to break the 450 ft loading wire into several parallel wires. We measured feedpoint Z, then used SimSmith to design a simple matching network with junkbox parts. It plays extremely well -- Glen's worked VK4YB and a lot of other stuff with it. 73, Jim K9YC On 3/7/2023 10:45 PM, Ed Cole wrote: My new 630m antenna will be a "T" vertical with four top wires formed by 80 & 40m dipoles. Feedline will be 40-foot 300-ohm open wire which will be shorted for use as a vertical and use the same base loading coil. Radial system will be wires lain in the lawn with staples from DXEngineering (so lawn can be mowed). Start out with six radials but can add to that over time to improve the antenna. The vertical will also set up for 160m use by using a different coil tap. __ 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] Vertical antennas Was: KX3 and KPA1500, compatibility
Couple comments: Vertical radials: I put up a top-loaded (very) short vertical for 630m (475-KHz). Top "hat" was two parallel 130-foot horizontal wires and vertical was three parallel wires 43-foot long (inverted-L). Used a BIG base loading coil but needed radials that normally would be over 600-foot long (1/4WL). I only had room for 70-foot radials. I was told to get some 3-foot wide chicken wire fencing and lay that out on top of the ground for radials. I put three down and also connected to the shield of my 120-foot run of 1-5/8 inch hardline as fourth radial. That system worked great and I was heard 4,000 miles away in Buffalo, NY (EIRP of 4w) on 500-KHz long duration CW. My new 630m antenna will be a "T" vertical with four top wires formed by 80 & 40m dipoles. Feedline will be 40-foot 300-ohm open wire which will be shorted for use as a vertical and use the same base loading coil. Radial system will be wires lain in the lawn with staples from DXEngineering (so lawn can be mowed). Start out with six radials but can add to that over time to improve the antenna. The vertical will also set up for 160m use by using a different coil tap. I once had a 4BTV which I bolted to the front bumper of my truck and it worked quite well without radials or counterpoise (heard Antarctica from Alaska on 20m SSB from a campground setup). No longer have it (use Hygain TH3mk4 at 50-foot, instead). 73, Ed - KL7UW --- Now, it has one "radial". Actually an Ufer ground, consisting of a concrete slab, 70 feet long by 10 feet wide, with 80 feet of 8AWG copper wire buried in it. The slab is actually a solar collection field for our swimming pool. I left a space in the middle for the antenna. I was going to do radials, but had a sudden thought - I'd be a fool if I didn't bury some wire in that concrete. So I ran to the local hardware store, grabbed a roll of 8AWG off their rack, and strung it around the site, hooking it up to the rebars. Then they came and poured the concrete. - Jerry, KF6VB __ 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] Vertical antennas Was: KX3 and KPA1500 compatibility
On 3/6/2023 9:27 PM, Eric Norris wrote: ON4UN's book, Guide to Low-Band DXing, has an excellent chapter on verticals. Yes, another quite useful resource on many topics. Its focus is 40-160M. In addition to antennas and radial systems/counterpoises, it sheds a lot of light on topography, as well as on propagation on these bands. These are things we read to understand how (and why) stuff works (and why some stuff doesn't!) 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] Vertical antennas Was: KX3 and KPA1500 compatibility
I operated my HF-2V vertical for about 10 years with 6 radials. Then, I added 60 more for 66 total radials. I thatched the living bejesus out of my back lawn, stapled down the radials bolted to a DXE SS plate, and the lawn regrew, the radials never to be seen again. The difference was astonishing. Tonight I worked 3B7M on 40m cw on that vertical, despite strong local noise. Admittedly, my KPA1500 was squeakin' from the freakin' But, on other occasions, I have worked a JA stopped on his local bridge running 5w. It's not a beam, or even a high dipole, but verticals do work with a proper counterpoise. ON4UN's book, Guide to Low-Band DXing, has an excellent chapter on verticals. RIP. 73 Eric WD6DBM On Mon, Mar 6, 2023, 3:00 PM Alan Bloom wrote: > On 3/6/23 15:08, Jim Brown wrote: > > Most (but not all) verticals need radials to transmit a decent signal. > > A vertical that needs radials is a lousy TX antenna without them. > > Right. > > I use a 6BTV, which is a 6-band trap vertical about 24 ft tall. With a > barefoot K4 at 100W I get out quite well. Obviously I can't compete > with the "big guns" running kilowatt amplifiers and beams at 120 feet, > but I do work lots of DX. I can crack most pileups with enough patience. > > The trick is that the antenna has 40 radials, each one 32 ft long buried > an inch or two in the sand at my desert location. > > The old joke that a vertical is an antenna that radiates equally poorly > in all directions is only true if you have a poor radial system. > > Alan N1AL > > __ > 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 norrislawfi...@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] Vertical antennas Was: KX3 and KPA1500 compatibility
I too have a 6BTV. It used to have 50 radials. They were a pain in the whatchum, always getting caught by the weed whacker. But they made a big difference in the performance of the antenna. Now, it has one "radial". Actually an Ufer ground, consisting of a concrete slab, 70 feet long by 10 feet wide, with 80 feet of 8AWG copper wire buried in it. The slab is actually a solar collection field for our swimming pool. I left a space in the middle for the antenna. I was going to do radials, but had a sudden thought - I'd be a fool if I didn't bury some wire in that concrete. So I ran to the local hardware store, grabbed a roll of 8AWG off their rack, and strung it around the site, hooking it up to the rebars. Then they came and poured the concrete. The Ufer ground seems to perform about as well as the radials did. If it didn't, I would have run radials - Jerry, KF6VB \ On 2023-03-06 14:59, Alan Bloom wrote: On 3/6/23 15:08, Jim Brown wrote: Most (but not all) verticals need radials to transmit a decent signal. A vertical that needs radials is a lousy TX antenna without them. Right. I use a 6BTV, which is a 6-band trap vertical about 24 ft tall. With a barefoot K4 at 100W I get out quite well. Obviously I can't compete with the "big guns" running kilowatt amplifiers and beams at 120 feet, but I do work lots of DX. I can crack most pileups with enough patience. The trick is that the antenna has 40 radials, each one 32 ft long buried an inch or two in the sand at my desert location. The old joke that a vertical is an antenna that radiates equally poorly in all directions is only true if you have a poor radial system. Alan N1AL __ 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 je...@tr2.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
[Elecraft] Vertical antennas Was: KX3 and KPA1500 compatibility
On 3/6/23 15:08, Jim Brown wrote: Most (but not all) verticals need radials to transmit a decent signal. A vertical that needs radials is a lousy TX antenna without them. Right. I use a 6BTV, which is a 6-band trap vertical about 24 ft tall. With a barefoot K4 at 100W I get out quite well. Obviously I can't compete with the "big guns" running kilowatt amplifiers and beams at 120 feet, but I do work lots of DX. I can crack most pileups with enough patience. The trick is that the antenna has 40 radials, each one 32 ft long buried an inch or two in the sand at my desert location. The old joke that a vertical is an antenna that radiates equally poorly in all directions is only true if you have a poor radial system. Alan N1AL __ 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
