Comments on: My homebrew vertical multiband hf antenna http://on3jt.byze.be/my-homebrew-vertical-multiband-hf-antenna Blog and website of a Belgian ham radio operator who likes to build antennas and other projects. Tue, 16 Feb 2010 12:36:01 +0100 http://wordpress.org/?v=2.8.4 hourly 1 By: Gordon http://on3jt.byze.be/my-homebrew-vertical-multiband-hf-antenna/comment-page-1#comment-40 Gordon Tue, 12 Aug 2008 11:01:56 +0000 http://on3jt.byze.be/my-homebrew-vertical-multiband-hf-antenna#comment-40 I made a similar vertical a few years ago using a fishing pole with wires held around it. It was mounted on the side of a house with elevated radials and it worked very well. It was only for three bands, 10m 15m 20m. Gordon GM4SVM I made a similar vertical a few years ago using a fishing pole with wires held around it. It was mounted on the side of a house with elevated radials and it worked very well. It was only for three bands, 10m 15m 20m.

Gordon

GM4SVM

]]> By: Sai http://on3jt.byze.be/my-homebrew-vertical-multiband-hf-antenna/comment-page-1#comment-38 Sai Fri, 01 Aug 2008 05:15:02 +0000 http://on3jt.byze.be/my-homebrew-vertical-multiband-hf-antenna#comment-38 Real good info on antenna my friend thanks for sharing. Hope to see u on air ...................73 de VU2SGW clear Real good info on antenna my friend thanks for sharing. Hope to see u on air ……………….73
de VU2SGW clear

]]> By: Neil G7AQK http://on3jt.byze.be/my-homebrew-vertical-multiband-hf-antenna/comment-page-1#comment-36 Neil G7AQK Fri, 20 Jun 2008 21:54:51 +0000 http://on3jt.byze.be/my-homebrew-vertical-multiband-hf-antenna#comment-36 I tuned up the antenna initially using just the counterpoise and it matched reasonably well. Attaching the earth improves things marginally but not much. I did find that trimming the length of the counterpoise for minimum SWR was much easier than adjusting the length of the radiator. The counterpoise wires run along the fence approx 150-300mm above the ground. The earth is connected to a 4 ft earth rod and the metal fence spikes supporting the boundary fence. I might try the two wire suggestion or even use two counterpoises of slightly different lengths. Neil I tuned up the antenna initially using just the counterpoise and it matched reasonably well. Attaching the earth improves things marginally but not much. I did find that trimming the length of the counterpoise for minimum SWR was much easier than adjusting the length of the radiator. The counterpoise wires run along the fence approx 150-300mm above the ground. The earth is connected to a 4 ft earth rod and the metal fence spikes supporting the boundary fence. I might try the two wire suggestion or even use two counterpoises of slightly different lengths.

Neil

]]> By: Joost http://on3jt.byze.be/my-homebrew-vertical-multiband-hf-antenna/comment-page-1#comment-35 Joost Fri, 20 Jun 2008 19:49:57 +0000 http://on3jt.byze.be/my-homebrew-vertical-multiband-hf-antenna#comment-35 Hi Neil, I just measured the bandwidth on 10 again. The 2:1 points are 28.603 and 29.607. My initial readings a year ago were more in the neighbourhood of 700 to 800 kHz (for what I can remember) . Strange effect :-) What about using 2 wires on 10 ? One tuned to 28.000 and the other to 29.500. I never tried it but who knows ? Or a alu tube instead of a wire ? I see that you have a ground stake, I don't have one on my roof, but it seems to be working. Hi Neil,

I just measured the bandwidth on 10 again. The 2:1 points are 28.603 and 29.607. My initial readings a year ago were more in the neighbourhood of 700 to 800 kHz (for what I can remember) . Strange effect :-)

What about using 2 wires on 10 ? One tuned to 28.000 and the other to 29.500. I never tried it but who knows ? Or a alu tube instead of a wire ?
I see that you have a ground stake, I don’t have one on my roof, but it seems to be working.

]]> By: Neil G7AQK http://on3jt.byze.be/my-homebrew-vertical-multiband-hf-antenna/comment-page-1#comment-34 Neil G7AQK Fri, 20 Jun 2008 19:30:24 +0000 http://on3jt.byze.be/my-homebrew-vertical-multiband-hf-antenna#comment-34 I have just found your site and was particularly interested in your multi-band vertical. I came up with a very similar solution about a year ago and the details can be found at http://g7aqk.uk.googlepages.com/Fantenna.pdf . I have improved the initial design by running a single 1/4 wave counterpoise horizontally for each band in addition to the earth connection. Bandwidth is OK for most of the bands but only covers about 500KHz of 10m. Neil I have just found your site and was particularly interested in your multi-band vertical. I came up with a very similar solution about a year ago and the details can be found at http://g7aqk.uk.googlepages.com/Fantenna.pdf . I have improved the initial design by running a single 1/4 wave counterpoise horizontally for each band in addition to the earth connection. Bandwidth is OK for most of the bands but only covers about 500KHz of 10m.

Neil

]]> By: Tony G0WFV http://on3jt.byze.be/my-homebrew-vertical-multiband-hf-antenna/comment-page-1#comment-33 Tony G0WFV Mon, 26 May 2008 12:29:38 +0000 http://on3jt.byze.be/my-homebrew-vertical-multiband-hf-antenna#comment-33 The current antenna system is deaf! I am unsure weather this is due to location or construction. As I can do little about the location, I can alter the construction so as to be sure I have kept to the original CobWebb spec as possible. The current antenna system is deaf! I am unsure weather this is due to location or construction. As I can do little about the location, I can alter the construction so as to be sure I have kept to the original CobWebb spec as possible.

]]> By: Mart http://on3jt.byze.be/my-homebrew-vertical-multiband-hf-antenna/comment-page-1#comment-30 Mart Sun, 18 May 2008 14:25:29 +0000 http://on3jt.byze.be/my-homebrew-vertical-multiband-hf-antenna#comment-30 Tony, do you want to use better cable because you want to use more power or it is better for reception also? Tony, do you want to use better cable because you want to use more power or it is better for reception also?

]]> By: Tony G0WFV http://on3jt.byze.be/my-homebrew-vertical-multiband-hf-antenna/comment-page-1#comment-25 Tony G0WFV Fri, 09 May 2008 17:01:05 +0000 http://on3jt.byze.be/my-homebrew-vertical-multiband-hf-antenna#comment-25 Keep plugging away at the CobWebb, Joost! I found it to be quiet on the bands it is resonant on (considering I live in the town centre!), and it's such an easy antenna to construct, but I think I've been a bit too tight with my money and constructed it with inferior wire (only 7 strand speaker wire instead of 42!!) I think at some point I will stump up the extra cash for a 50m roll of 42 strand Fig8 cable! Just out of interest to you guys, I used 4 x 3m telescopic windsock masts for the spreaders (available from http://www.kiteshop.co.uk/xcart/outdoor-fun/wind-spinners/telescopic-pole_p912.html for £2.99 each - approx €3.75) I unscrewed the endcap and remove the last 1m (or so!) telescopic element leaving you with the perfect 2m (ish!) spreader for a CobWebb! (the 4 x 1m sections have since been used to construct a bodged up 2m Moxon!) As my antenna was always going to be in the loft, it is held together with cable ties and the centre cross is two pieces of wood screwed together at right angles, with holes drilled in them and the winsock masts cable tied in place through the holes! Simple, effective, and strong enough for indoor use where wind is not going to be a problem! The feedpoint box is resting on an old kitbag! Tony Keep plugging away at the CobWebb, Joost! I found it to be quiet on the bands it is resonant on (considering I live in the town centre!), and it’s such an easy antenna to construct, but I think I’ve been a bit too tight with my money and constructed it with inferior wire (only 7 strand speaker wire instead of 42!!) I think at some point I will stump up the extra cash for a 50m roll of 42 strand Fig8 cable!

Just out of interest to you guys, I used 4 x 3m telescopic windsock masts for the spreaders (available from http://www.kiteshop.co.uk/xcart/outdoor-fun/wind-spinners/telescopic-pole_p912.html for £2.99 each – approx €3.75) I unscrewed the endcap and remove the last 1m (or so!) telescopic element leaving you with the perfect 2m (ish!) spreader for a CobWebb! (the 4 x 1m sections have since been used to construct a bodged up 2m Moxon!)

As my antenna was always going to be in the loft, it is held together with cable ties and the centre cross is two pieces of wood screwed together at right angles, with holes drilled in them and the winsock masts cable tied in place through the holes! Simple, effective, and strong enough for indoor use where wind is not going to be a problem! The feedpoint box is resting on an old kitbag!

Tony

]]> By: Joost http://on3jt.byze.be/my-homebrew-vertical-multiband-hf-antenna/comment-page-1#comment-24 Joost Thu, 01 May 2008 05:31:11 +0000 http://on3jt.byze.be/my-homebrew-vertical-multiband-hf-antenna#comment-24 Hi Mart, I really can't tell. The Cobwebb has never reached the roof so side by side comparision is never done. I hope that Janne OH1GTF can bring an answer if his cobwebb is finished. I'm pretty shure his is finished before I have rebuilt mine :-) The next problem is that I don't have any other antennas to compare with, I find the GP pretty good with normal noise levels. But what is normal if you can't compare.... Joost Hi Mart,

I really can’t tell. The Cobwebb has never reached the roof so side by side comparision is never done. I hope that Janne OH1GTF can bring an answer if his cobwebb is finished. I’m pretty shure his is finished before I have rebuilt mine :-)
The next problem is that I don’t have any other antennas to compare with, I find the GP pretty good with normal noise levels. But what is normal if you can’t compare….

Joost

]]> By: Mart http://on3jt.byze.be/my-homebrew-vertical-multiband-hf-antenna/comment-page-1#comment-23 Mart Wed, 30 Apr 2008 22:49:39 +0000 http://on3jt.byze.be/my-homebrew-vertical-multiband-hf-antenna#comment-23 Hi, do you pick up lots of manmade noise with GP? Was Cobwebb more quiet? 73, Mart Hi,

do you pick up lots of manmade noise with GP?
Was Cobwebb more quiet?

73, Mart

]]>