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#1
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What abt using my 13B2 for us on 440? I don't have an analyzer for that band
nor a swr meter. What are the thoughts on this? I have a friend in Houston who does it and verifies it to be ok. Responses and thoughts appreciated. |
#2
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"AO KD5FXT" wrote in message
... What abt using my 13B2 for us on 440? I don't have an analyzer for that band nor a swr meter. What are the thoughts on this? I have a friend in Houston who does it and verifies it to be ok. Responses and thoughts appreciated. Seem like a waste of a good Cushcraft 13B2 (13 element yagi) 2 meter antenna ($ 150 MSRP) for 440 MHz antenna. http://www.chq-inc.com/cush/13B2.html What are you trying do on 70 cm ? (440MHz) SSB/CW DX, FM repeaters, ATV, satellite work 1. When you move from 2 meters to 70 cm -- the coax you use from you operating position to the antenna becomes much more important than at HF or low VHF frequencies. For example, for 100 feet of coax the attenuation in dB [from Cable X-perts charts] http://www.cablexperts.com/cfdocs/ca...USA_ship=1&c=0 RG-213/U at 150 MHz - 2.8 dB; at 450 MHz - 5.2 dB LMR-400 at 150 MHz - 1.5 dB; at 450 MHz - 2.7 dB 2. Some designs to consider ! K5OE 70 cm yagi designs (in this case for AO-40) http://members.aol.com/k5oe/P3D_ant/P3D_yagi.htm VK3KHB 8 element design for ATV usage [Uses 1/8" (~3 - 5 mm) solid rod for elements and round or square aluminum tube (~ 10 mm) http://www.gak.net.au/vk3khb/atv/antdesign.htm WiMo products [Germany] - great for ideas http://www.wimo.com/verteiler-e.htm?s1_e.htm KK5UFO designs http://www.homestead.com/kk5ufo/VHFbluprint.html XE1MEX design (for 2m and 70cm) http://xe1mex.gq.nu/antenas/yagi.html Martin DK7ZB very nice designs http://www.qsl.net/dk7zb/start1.htm Derek, G4CQM http://www.g4cqm.btinternet.co.uk/an...gner/yagis.htm That's a start !! w9gb -- DO NOT use Reply. Only reply through ARRL forwarding service to W9GB |
#3
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I forgot Kent Britain, WA5VJB
Cheap Yagi antennas for VHF / UHF http://www.clarc.org/Articles/uhf.htm Element spacing and lengths provided on web site w9gb -- DO NOT use Reply. Only reply through ARRL forwarding service to W9GB |
#4
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If you do this. Don't assume the main lobe will be straight ahead. I have
used a 7 el Cushcraft on 432, and found its best direction was about 30 degrees to one side. It had a gamma match. Tam/WB2TT "AO KD5FXT" wrote in message ... What abt using my 13B2 for us on 440? I don't have an analyzer for that band nor a swr meter. What are the thoughts on this? I have a friend in Houston who does it and verifies it to be ok. Responses and thoughts appreciated. |
#5
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G.Beat wrote:
"AO KD5FXT" wrote in message ... What abt using my 13B2 for us on 440? I don't have an analyzer for that band nor a swr meter. What are the thoughts on this? I have a friend in Houston who does it and verifies it to be ok. Responses and thoughts appreciated. Seem like a waste of a good Cushcraft 13B2 (13 element yagi) 2 meter antenna ($ 150 MSRP) for 440 MHz antenna. http://www.chq-inc.com/cush/13B2.html What are you trying do on 70 cm ? (440MHz) SSB/CW DX, FM repeaters, ATV, satellite work 1. When you move from 2 meters to 70 cm -- the coax you use from you operating position to the antenna becomes much more important than at HF or low VHF frequencies. For example, for 100 feet of coax the attenuation in dB [from Cable X-perts charts] http://www.cablexperts.com/cfdocs/ca...ub=0&bskt=0&US A_ship=1&c=0 RG-213/U at 150 MHz - 2.8 dB; at 450 MHz - 5.2 dB LMR-400 at 150 MHz - 1.5 dB; at 450 MHz - 2.7 dB 2. Some designs to consider ! K5OE 70 cm yagi designs (in this case for AO-40) http://members.aol.com/k5oe/P3D_ant/P3D_yagi.htm VK3KHB 8 element design for ATV usage [Uses 1/8" (~3 - 5 mm) solid rod for elements and round or square aluminum tube (~ 10 mm) http://www.gak.net.au/vk3khb/atv/antdesign.htm WiMo products [Germany] - great for ideas http://www.wimo.com/verteiler-e.htm?s1_e.htm KK5UFO designs http://www.homestead.com/kk5ufo/VHFbluprint.html XE1MEX design (for 2m and 70cm) http://xe1mex.gq.nu/antenas/yagi.html Martin DK7ZB very nice designs http://www.qsl.net/dk7zb/start1.htm Derek, G4CQM http://www.g4cqm.btinternet.co.uk/an...gner/yagis.htm That's a start !! w9gb Also the 'VHF/UHF Long Yagi Workshop' on my site. -- 73 from Ian G3SEK 'In Practice' columnist for RadCom (RSGB) Editor, 'The VHF/UHF DX Book' http://www.ifwtech.co.uk/g3sek |
#6
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![]() "Ian White, G3SEK" wrote in message news ![]() G.Beat wrote: "AO KD5FXT" wrote in message ... 2. Some designs to consider ! K5OE 70 cm yagi designs (in this case for AO-40) http://members.aol.com/k5oe/P3D_ant/P3D_yagi.htm [snip] That's a start !! w9gb Also the 'VHF/UHF Long Yagi Workshop' on my site. -- 73 from Ian G3SEK 'In Practice' columnist for RadCom (RSGB) Editor, 'The VHF/UHF DX Book' http://www.ifwtech.co.uk/g3sek Sorry Ian ! I did not have your site readily bookmarked !! [That's been addressed now ! ] Cheers Greg w9gb -- DO NOT use Reply. Only reply through ARRL forwarding service to W9GB |
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