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Alternate material j pole construction question.
I am experimenting making a j pole out of 1/2 inch conduit. What I am
thinking of doing is making it like a "u" in that each piece, the radiator, stub and shorting bar are cut at 45 degree angles and welded togther. I have the dimensions using the 1/2 inch copper. How do i measure each pieces "length"? I mean in the copper plan they use t fittings and measure the radiator length starting incide the t fitting where it is lower than the shorting bar. My ides was to just measure the end of the angled piece where I cut it to the top, but not sure if this is right. What do you think? Also, since an antenna constructed this way will not have an "extended leg" to mount to a mast, would it be acceptable to mount the shorted horizontal section to the mast? Will this cause problems? Any help is appreciated. I hope to work on this tomorrow. |
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#3
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Eskay wrote: On 21 Jan 2005 05:33:37 -0800, wrote: I am experimenting making a j pole out of 1/2 inch conduit. What I am thinking of doing is making it like a "u" in that each piece, the radiator, stub and shorting bar are cut at 45 degree angles and welded togther. I have the dimensions using the 1/2 inch copper. How do i measure each pieces "length"? I mean in the copper plan they use t fittings and measure the radiator length starting incide the t fitting where it is lower than the shorting bar. My ides was to just measure the end of the angled piece where I cut it to the top, but not sure if this is right. What do you think? Also, since an antenna constructed this way will not have an "extended leg" to mount to a mast, would it be acceptable to mount the shorted horizontal section to the mast? Will this cause problems? Any help is appreciated. I hope to work on this tomorrow. I am assuming that you are talking about using EMT conduit. It will rust pretty quickly and the welds will rust even sooner. Why not use 1/2 inch copper plumping pipe? 73 de Eskay Yes EMT conduit. I will paint it to keep it from rusting. I have emt at my house and I can weld it. I dont have enough copper and I have never soldered copper plus I would have to buy a bunch of fittings. |
#4
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#5
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Richard Clark wrote: On 21 Jan 2005 05:33:37 -0800, wrote: I hope to work on this tomorrow. That is all very nice and well, but the tenor of your questions also suggest that you, being unlicensed, are about to embark upon unlawful radio transmissions. This will not pass unnoticed in your community. If you interfere with any service, there are many hams technically equipped to strip any notion of anonymity (an illusion even here) from your transmissions - just like in the movies. As I pointed out in a past post, there are several radio clubs in your area. You should join one before they join you. I do have my license. Why do you think I dont? It is KG4GER if you dont believe me. |
#6
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wrote:
I do have my license. Why do you think I dont? It is KG4GER if you dont believe me. Hey Don, with a QRZ.com birth date of "01 Nov 0001", you must have known Jesus. :-) Why don't you start with the Arrow Antenna design? It's actually a Zepp design where the driven element is 1/4WL and the parallel "grounded" element is 3/4WL. -- 73, Cecil http://www.qsl.net/w5dxp ----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 100,000 Newsgroups ---= East/West-Coast Server Farms - Total Privacy via Encryption =--- |
#7
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Stryped wrote:
"I am making a J-pole out of 1/2 inch conduit." There ia a 144 MHz Super-J in the "ARRL Antenna Book". It`s on page 16-24 of my 19th edition. Individual piece drawings and measurements are presented for novice builders. The "Antenna Book" Maritime Antenna is "Super" because it is a collinear using (2) 1/2-wave sections, in phase, and end to end. For a simple J-pole, eliminate one 1/2-wave section and the 1/4-wave phase-inverting stub. Stainless steel is used fotr the "Super J-pole", but rustable steel can be used if deesired. Best regards, Richard Harrison, KB5WZI |
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#9
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Cecil Moore wrote: wrote: I do have my license. Why do you think I dont? It is KG4GER if you dont believe me. Hey Don, with a QRZ.com birth date of "01 Nov 0001", you must have known Jesus. :-) Why don't you start with the Arrow Antenna design? It's actually a Zepp design where the driven element is 1/4WL and the parallel "grounded" element is 3/4WL. -- 73, Cecil http://www.qsl.net/w5dxp ----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 100,000 Newsgroups ---= East/West-Coast Server Farms - Total Privacy via Encryption =--- I actually plan to, but will have to order aluminum to do it. I plan on making both and comparing them. |
#10
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Ok.
Don KG4GER |
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