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#1
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I've done a bit of reading on G5RV's and I plan to just use the
standard configuration of a 102' dipole center fed with 32' of 450 Ohm ladder line. Then I'm going to attach RG8X to the ladder line and right near the connection construct a current choke of 8 turns of coax about 6" in diameter. And then run the coax to my antenna tuner. some of the sites I've run across mention that the G5RV needs at least 70' of coax to function properly. This seems pretty lossy to me and I don't see the need for the 70' of coax, perhaps someone can enlighten me ? I'd like to keep the run of coax as short as possible. Also I was digging through my insulators and I can't find one that would offer strain relief for the ladder line and perhaps a connection on top to use a wire or rope to add support to the center of the antenna. I wonder if anyone has a source for one. Once again, thanks in advance. 73 Gary K8IQ |
#2
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HI Gary,
If you have read the excellent Article by Cebik you should take a look at it you can find it at http://www.cebik.com/wire/g5rv.html The best thing if your using 450 ohm window line would be the ladder grabber think you can get it from the Wireman www.thewireman.com the 70' of coax helps on 3.5 mhz but i'm with you keep it as short as possible. |
#3
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Gary wrote:
Also I was digging through my insulators and I can't find one that would offer strain relief for the ladder line and perhaps a connection on top to use a wire or rope to add support to the center of the antenna. I wonder if anyone has a source for one. I use the black UV-resistant tie wraps for strain relief. Run the tie wrap through one of the ladder-line windows and then through the hole in the insulator. With stranded ladder-line, I have had absolutely no problem with this method. -- 73, Cecil, W5DXP ----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups ----= East and West-Coast Server Farms - Total Privacy via Encryption =---- |
#4
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Gary wrote:
I've done a bit of reading on G5RV's and I plan to just use the standard configuration of a 102' dipole center fed with 32' of 450 Ohm ladder line. According to EZNEC, here are the 50 ohm SWRs that you will encounter if your 450 ohm ladder-line has a velocity factor of 0.9. 3.8HMz, 17:1 7.2MHz, 4.8:1 10.125MHz, 55:1 14.2MHz, 2:1 18.14MHz, 35:1 21.3MHz, 23:1 25.95MHz, 2.5:1 28.4MHz, 60:1. You will definitely need a tuner. One wonders if you couldn't do better with ladder-line all the way to the tuner. -- 73, Cecil, W5DXP ----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups ----= East and West-Coast Server Farms - Total Privacy via Encryption =---- |
#5
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On Fri, 22 Apr 2005 06:17:21 -0400, Gary wrote:
I've done a bit of reading on G5RV's and I plan to just use the standard configuration of a 102' dipole center fed with 32' of 450 Ohm ladder line. Then I'm going to attach RG8X to the ladder line and right near the connection construct a current choke of 8 turns of coax about 6" in diameter. And then run the coax to my antenna tuner. some of the sites I've run across mention that the G5RV needs at least 70' of coax to function properly. This seems pretty lossy to me and I don't see the need for the 70' of coax, perhaps someone can enlighten me ? I'd like to keep the run of coax as short as possible. See g5rv's article at http://www.qsl.net/aa3px/g5rv.htm He said you can use up to 70 feet of coax and not suffer too much loss; the shorter the better, tho' He also had other recommendations for feedlines. bob k5qwg Also I was digging through my insulators and I can't find one that would offer strain relief for the ladder line and perhaps a connection on top to use a wire or rope to add support to the center of the antenna. I wonder if anyone has a source for one. Once again, thanks in advance. 73 Gary K8IQ |
#6
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On 22 Apr 2005 04:44:03 -0700, "KC1DI" wrote:
HI Gary, If you have read the excellent Article by Cebik you should take a look at it you can find it at http://www.cebik.com/wire/g5rv.html The best thing if your using 450 ohm window line would be the ladder grabber think you can get it from the Wireman www.thewireman.com the 70' of coax helps on 3.5 mhz but i'm with you keep it as short as possible. Thanks for the info !! 73 Gary K8IQ |
#7
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On Fri, 22 Apr 2005 10:46:08 -0500, Cecil Moore
wrote: Gary wrote: Also I was digging through my insulators and I can't find one that would offer strain relief for the ladder line and perhaps a connection on top to use a wire or rope to add support to the center of the antenna. I wonder if anyone has a source for one. I use the black UV-resistant tie wraps for strain relief. Run the tie wrap through one of the ladder-line windows and then through the hole in the insulator. With stranded ladder-line, I have had absolutely no problem with this method. Thanks Cecil, I had that idea in the back of my head but didn't know how practical it was. I've got large number of black tie wraps already. I don't know if they're UV resistant or not but I'll give it a try. 73 Gary |
#8
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On Fri, 22 Apr 2005 11:13:44 -0500, Cecil Moore
wrote: Gary wrote: I've done a bit of reading on G5RV's and I plan to just use the standard configuration of a 102' dipole center fed with 32' of 450 Ohm ladder line. According to EZNEC, here are the 50 ohm SWRs that you will encounter if your 450 ohm ladder-line has a velocity factor of 0.9. 3.8HMz, 17:1 7.2MHz, 4.8:1 10.125MHz, 55:1 14.2MHz, 2:1 18.14MHz, 35:1 21.3MHz, 23:1 25.95MHz, 2.5:1 28.4MHz, 60:1. You will definitely need a tuner. One wonders if you couldn't do better with ladder-line all the way to the tuner. Well I've got two MFJ tuners ( one for use while the other's in for repairs ;-) ) . The 949E is in for repairs, I've had it for about a year or so and ( I think ) the diodes popped on the SWR/Wattmeter circuit. The other tuner is the MFJ -993 Auto Tuner. The auto tuner probably won't tune anything over 30:1 and I doubt the 949E would either. But I'm primarily interested in 80/40/20 meters where the tuners will handle the SWR. I could use the ladder line to the tuner's wire input but that would require it to go through the 4:1 balun and that would make it too low for the frequencies I'm interested in so I'll probably just stick with a real short run of coax and use the regular 52 ohm coax input. Thanks for the information. 73 Gary K8IQ |
#9
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On Fri, 22 Apr 2005 18:40:19 GMT, Bob Miller
wrote: On Fri, 22 Apr 2005 06:17:21 -0400, Gary wrote: I've done a bit of reading on G5RV's and I plan to just use the standard configuration of a 102' dipole center fed with 32' of 450 Ohm ladder line. Then I'm going to attach RG8X to the ladder line and right near the connection construct a current choke of 8 turns of coax about 6" in diameter. And then run the coax to my antenna tuner. some of the sites I've run across mention that the G5RV needs at least 70' of coax to function properly. This seems pretty lossy to me and I don't see the need for the 70' of coax, perhaps someone can enlighten me ? I'd like to keep the run of coax as short as possible. See g5rv's article at http://www.qsl.net/aa3px/g5rv.htm He said you can use up to 70 feet of coax and not suffer too much loss; the shorter the better, tho' He also had other recommendations for feedlines. bob k5qwg Thanks for the info and the link Bob. 73 Gary K8IQ Also I was digging through my insulators and I can't find one that would offer strain relief for the ladder line and perhaps a connection on top to use a wire or rope to add support to the center of the antenna. I wonder if anyone has a source for one. Once again, thanks in advance. 73 Gary K8IQ |
#10
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