Multi Band Dipoles
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snip It confirms the very dismal performance of *all* those "popular" HF short loading-coil verticals in comparison to the most simple, basic, inexpensive quarter-wave vertical. TANSTAAFL! Likewise, the horizontal antenna comparisons confirm the overall superiority of a simple dipole over other horizontal types being tested. snip Mike, I've only been at this game for 12 months so can't really comment on the comparisons but my multi band dipole works a treat. It is a home brew set up with 3 horizontal dipoles cut for 80/40/20m one above the other with about 1-2 feet separation at the ends. All on the same coax with no balun or ground connection. The wire is cheap annealed solid copper PVC insulated mains wiring cable 2.5 sq mm (slightly larger than your #14AWG). The 80m wires take the full weight with no problems and I keep a lot of tension on it using a very heavy weight and a pulley. The centre is at about 25feet and the ends at 30 feet and the whole thing is pretty much in the clear. You need plenty of patience to get everything resonant with lots of ladder climbing, hanging out of loft windows and hoisting up and down but now I have swr between 1.3 and 1.0 on 80,40,20 & 15. As I say I can't compare with anything else but I get great reports with qrp using this arrangement. When I get the time will probably put up another dipole for 30m. Martin M0KWV K1#1534 Why not take a look at our Web site? http://www.simoncarves.com ************************************************************************* The information in this email and any attachments may contain privileged and/or confidential information intended solely for the use of the individual or entity to whom it is addressed. If the reader of this email is not the intended addressee, or the employee or agent responsible to deliver it to the addressee, you are hereby notified that any dissemination, distribution or copying of this communication is strictly prohibited. If you have received this communication in error, please notify me by telephone or email and delete all copies immediately. ************************************************************************* _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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In my opinion, one of the most effective antennas I have used is a rotatable
trap dipole such as the Cushcraft D3, D3W and D4. I have used them all. Advantages: Single support, easier to get up at a reasonable height than a dipole and no drooping ends as in inverted V. They are a bit pricey, but are sturdy. I mount them at the top of trees on my property, placing them (with the help of radiation angle/terrain software}at strategic locations to take advantage of the extreme sloping foreground that is my property. Alan, N3BJ Bent Mountain, VA ----- Original Message ----- From: <[hidden email]> To: <[hidden email]>; <[hidden email]> Sent: Monday, July 05, 2004 5:37 AM Subject: [Elecraft] Multi Band Dipoles > > > > > snip > > It confirms the very dismal performance of *all* those "popular" HF short > loading-coil verticals in comparison to the most simple, basic, inexpensive > quarter-wave vertical. TANSTAAFL! > > Likewise, the horizontal antenna comparisons confirm the overall > superiority of a simple dipole over other horizontal types being tested. > > snip > > Mike, I've only been at this game for 12 months so can't really comment on > the comparisons but my multi band dipole works a treat. It is a home brew > set up with 3 horizontal dipoles cut for 80/40/20m one above the other > about 1-2 feet separation at the ends. All on the same coax with no balun > or ground connection. The wire is cheap annealed solid copper PVC insulated > mains wiring cable 2.5 sq mm (slightly larger than your #14AWG). The 80m > wires take the full weight with no problems and I keep a lot of tension on > it using a very heavy weight and a pulley. The centre is at about 25feet > and the ends at 30 feet and the whole thing is pretty much in the clear. > > You need plenty of patience to get everything resonant with lots of ladder > climbing, hanging out of loft windows and hoisting up and down but now I > have swr between 1.3 and 1.0 on 80,40,20 & 15. As I say I can't compare > with anything else but I get great reports with qrp using this arrangement. > When I get the time will probably put up another dipole for 30m. > > Martin > M0KWV > K1#1534 > > > > Why not take a look at our Web site? > http://www.simoncarves.com > > ************************************************************************* > The information in this email and any attachments may contain > privileged and/or confidential information intended solely for > the use of the individual or entity to whom it is addressed. > If the reader of this email is not the intended addressee, or the > employee or agent responsible to deliver it to the addressee, > you are hereby notified that any dissemination, distribution or > copying of this communication is strictly prohibited. > If you have received this communication in error, please notify > me by telephone or email and delete all copies immediately. > ************************************************************************* > > _______________________________________________ > Elecraft mailing list > Post to: [hidden email] > You must be a subscriber to post to the list. > Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/subscribers.htm > Elecraft web page: http://www.elecraft.com > _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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In reply to this post by Martin.Evans
Martin wrote:
>...my multi band dipole works a treat. It is a home brew set up with >3 horizontal dipoles cut for 80/40/20m one above the other with >about 1-2 feet separation at the ends. All on the same coax with no balun >or ground connection. The wire is cheap annealed solid copper PVC insulated >mains wiring cable 2.5 sq mm (slightly larger than your #14AWG). The 80m >wires take the full weight with no problems and I keep a lot of tension on >it using a very heavy weight and a pulley Hi Martin, I've used the same arrangement for a home fixed installation. It's inexpensive and works very well, much better than using traps in a single wire. The only real downside is that it begins to look like a spider web as bands are added. It's just a little too difficult to use in a portable temporary installation. 73, Mike / KK5F _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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In reply to this post by Martin.Evans
On Mon, 5 Jul 2004 10:37:25 +0100, [hidden email] wrote:
>Mike, I've only been at this game for 12 months so can't really comment on >the comparisons but my multi band dipole works a treat. It is a home brew >set up with 3 horizontal dipoles cut for 80/40/20m one above the other with >about 1-2 feet separation at the ends. All on the same coax with no balun >or ground connection. I am very much a fan of parallel wire dipoles like yours, and have built a half dozen of them so far for different combinations of bands (for Field Day, and for a station I'm putting together at W6BX). I use the DX Engineering balun, not so much for its power rating (2 KW continuous), but for its exceptional build quality and performance specs. An advantage of this construction is that each antenna is a full sized half wave dipole, and is thus tunes more broadly than one loaded by traps or loading coils. You also avoid the loss associated with traps. My construction uses 16" long spacers cut from PVC conduit (labeled UV resistant) and THHN wire that I bought at Home Depot. At W6BX, on a mountaintop where there is a lot of wind and ice, the long element that carries the load is #8 copper, while the parallel dipoles are #10. For Field Day, I used #12. That said, I am also quite pleased with the shortened 80/40 dipole that I bought from HyPower antenna company, and with the 160/80/40 antenna that I built using HyPower's loading coils. http://www.freewebs.com/hypower/ For the 80/40 design, the loading coils self resonate at 40 meters, so the inner dipole is a half wave on 40. The total length of the antenna (tuned for 3575) is about 90 ft, which lets it fit on my city lot. This antenna, about 45 ft high, has worked 34 countries on 80 and 95 on 40 with 100 watts in about 9 months. It also is pretty good in some directions on 30 meters. The 160/80/40 design is a scaled-up version of the 80/40 design for 160/80, with a parallel wire dipole for 40. It is installed at W6BX, and works VERY well. Jim Brown K9YC _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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