{"id":23472,"date":"2017-01-17T08:49:19","date_gmt":"2017-01-17T12:49:19","guid":{"rendered":"http:\/\/swling.com\/blog\/?p=23472"},"modified":"2017-01-17T08:49:19","modified_gmt":"2017-01-17T12:49:19","slug":"southgate-arc-what-is-a-balun-and-how-to-make-one-cheaply","status":"publish","type":"post","link":"https:\/\/swling.com\/blog\/2017\/01\/southgate-arc-what-is-a-balun-and-how-to-make-one-cheaply\/","title":{"rendered":"Southgate ARC: What Is a Balun and How to Make One Cheaply"},"content":{"rendered":"

\"\"<\/a><\/p>\n

(Source: Southgate ARC<\/a>)<\/p>\n

\n

Ham Radio – What Is a Balun and How to Make One Cheaply<\/h3>\n

A Balun is a transformer which allows coaxial cable, which is an unbalanced lead to be connected to a balanced load, for example a resonant aerial.<\/p>\n

The 1:1 balun is often called a choke balun, it works by eliminating Radio Frequency currents flowing on the outside of your coaxial cable, this is important because it prevents the pattern of the dipole becoming distorted and prevents the braid of the coaxial cable radiating.<\/p>\n

Connecting coax to your resonant dipole which can be configured in a V shape or in a sloping fashion, however serious power loss and feeder radiation can occur without the use of a balun transformer. No one wants to induce Radio Frequency currents into Television receivers or Broadcast equipment as it may result in disputes with neighbours and could possibly lead to your station having to close down. Try to keep the centre of your aerial away from buildings as it may induce Radio currents into the mains wiring.<\/p>\n

Building a choke is not difficult all you need is some plastic pipe available from many Do It Yourself outlets and warehouses. I use a length of about 1 foot of plastic pipe and 21 feet of coaxial cable, the length of the pipe and diameter is chosen because it works well if using R-G-5-8 coax the ends of the pipe can be sealed after placing a SO-239 connector for your coaxial lead. I use two bolts and solder tags at the other end of the pipe to connect the ends of the dipole to the choke.<\/p>\n

When wrapping your coax around the pipe don’t use too much force as it may damage the inner braid and space the turns away from each other by a millimetre or two. R-G-2-1-3 coax around 21 feet used with 5 inch pipe will handle 400 watts pf power. Wire ties can be used to hold the turns together along the length of the pipe. Using these measurements your choke will cover all of the ham radio bands from 1.8 Megahertz through to 28 Megahertz and will keep the radiation pattern.<\/p>\n

Using a dummy load connected to the choke and transmitting 100 watts from my transmitter indicated an S.W.R. readings of around 1.5 to 1 at 3.5 Megahertz when testing 28 Megahertz the S.W.R. reading came down to 1.1 to 1 which is an excellent match. Using the choke as it should be at the feed point of a dipole cut for 40 metres give an S.W.R. reading of 1.2 to 1. The highest reading was 1.5 to 1 when using 18 Megahertz but the rest of the High frequency bands gave me very acceptable matching.<\/p>\n

By
\nJohn Allsopp G4YDM
\nhttps:\/\/g4ydm.blogspot.co.uk\/<\/a><\/p>\n

Article Source:
\nhttp:\/\/EzineArticles.com\/expert\/John_Allsopp\/1925417<\/a><\/p>\n

Article Source:
\nhttp:\/\/EzineArticles.com\/9615600<\/a><\/p><\/blockquote>\n","protected":false},"excerpt":{"rendered":"

(Source: Southgate ARC) Ham Radio – What Is a Balun and How to Make One Cheaply A Balun is a transformer which allows coaxial cable, which is an unbalanced lead to be connected to a balanced load, for example a resonant aerial. The 1:1 balun is often called a choke balun, it works by eliminating […]<\/p>\n","protected":false},"author":15,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"jetpack_post_was_ever_published":false,"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":true,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"font":"","enabled":false},"version":2}},"categories":[4199,3607,545,3,43],"tags":[1643,5838,580],"class_list":["post-23472","post","type-post","status-publish","format-standard","hentry","category-accessories","category-antennas","category-ham-radio","category-news","category-shortwave-radio","tag-antennas","tag-baluns","tag-southgate-arc"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"","jetpack_shortlink":"https:\/\/wp.me\/pn3uc-66A","jetpack-related-posts":[{"id":46679,"url":"https:\/\/swling.com\/blog\/2020\/12\/how-to-build-a-simple-linear-loaded-dipole-for-low-noise-shortwave-radio-listening\/","url_meta":{"origin":23472,"position":0},"title":"How to Build a Simple Linear-Loaded Dipole for Low-Noise Shortwave Radio Listening","author":"Thomas","date":"December 3, 2020","format":false,"excerpt":"Many thanks to SWLing Post contributor and RX antenna guru, Grayhat, for another excellent guest post focusing on compact, low-profile urban antennas: A linear loaded dipole for the SWL by Grayhat What follows is the description of an antenna which may allow to obtain good performances even in limited space,\u2026","rel":"","context":"In "AM"","block_context":{"text":"AM","link":"https:\/\/swling.com\/blog\/category\/am\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2020\/11\/Map.jpg?resize=350%2C200&ssl=1","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2020\/11\/Map.jpg?resize=350%2C200&ssl=1 1x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2020\/11\/Map.jpg?resize=525%2C300&ssl=1 1.5x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2020\/11\/Map.jpg?resize=700%2C400&ssl=1 2x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2020\/11\/Map.jpg?resize=1050%2C600&ssl=1 3x"},"classes":[]},{"id":42595,"url":"https:\/\/swling.com\/blog\/2020\/04\/diy-how-to-build-a-noise-cancelling-passive-loop-ncpl-antenna\/","url_meta":{"origin":23472,"position":1},"title":"DIY: How to build a Noise-Cancelling Passive Loop (NCPL) antenna","author":"Thomas","date":"April 5, 2020","format":false,"excerpt":"I've gotten an number of inquiries from SWLing Post readers asking for a step-by-step guide to building the passive loop antenna I've mentioned in a number of previous posts. This antenna is the homebrew version of the commercially-available\u00a0 Airspy Youloop. It works a treat. And, yes, folks...it's fun to build.\u2026","rel":"","context":"In "Accessories"","block_context":{"text":"Accessories","link":"https:\/\/swling.com\/blog\/category\/accessories\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2020\/04\/Inked-SpyTenna3-e1585933710848.jpg?resize=350%2C200&ssl=1","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2020\/04\/Inked-SpyTenna3-e1585933710848.jpg?resize=350%2C200&ssl=1 1x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2020\/04\/Inked-SpyTenna3-e1585933710848.jpg?resize=525%2C300&ssl=1 1.5x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2020\/04\/Inked-SpyTenna3-e1585933710848.jpg?resize=700%2C400&ssl=1 2x"},"classes":[]},{"id":40280,"url":"https:\/\/swling.com\/blog\/2019\/10\/the-nooelec-balun-19-v2\/","url_meta":{"origin":23472,"position":2},"title":"The NooElec Balun 1:9 v2","author":"Thomas","date":"October 18, 2019","format":false,"excerpt":"Many thanks to SWLing Post contributor, Grayhat, who writes: Hi Thomas, was about to write you about some infos related to the NooElec balun when found that they now offer a v2 model: https:\/\/www.nooelec.com\/store\/balun-one-nine-v2-barebones.html The new balun has the same schematic as the previous one: But it is slightly bigger,\u2026","rel":"","context":"In "Antennas"","block_context":{"text":"Antennas","link":"https:\/\/swling.com\/blog\/category\/antennas\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2019\/10\/balun_one_nine_schematic.jpg?resize=350%2C200&ssl=1","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2019\/10\/balun_one_nine_schematic.jpg?resize=350%2C200&ssl=1 1x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2019\/10\/balun_one_nine_schematic.jpg?resize=525%2C300&ssl=1 1.5x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2019\/10\/balun_one_nine_schematic.jpg?resize=700%2C400&ssl=1 2x"},"classes":[]},{"id":32482,"url":"https:\/\/swling.com\/blog\/2018\/05\/how-to-build-sm0vpos-20-meter-magnetic-loop-antenna\/","url_meta":{"origin":23472,"position":3},"title":"How to build SM0VPO’s 20 meter magnetic loop antenna","author":"Thomas","date":"May 30, 2018","format":false,"excerpt":"A few days ago, SWLing Post contributor, Robert Gulley (AK3Q), pointed me to an excellent website by Harry Lythall (SM0VPO) which is chock-full of various homebrew radio projects. In particular, we both were impressed with Harry's 20 Meter Loop Antenna--it's such a simple project and requires no special order components.\u2026","rel":"","context":"In "Antennas"","block_context":{"text":"Antennas","link":"https:\/\/swling.com\/blog\/category\/antennas\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2018\/05\/20m_ant_05.jpg?resize=350%2C200&ssl=1","width":350,"height":200},"classes":[]},{"id":49992,"url":"https:\/\/swling.com\/blog\/2021\/08\/grayhats-ncpl-noise-cancelling-passive-loop-antenna-tweak\/","url_meta":{"origin":23472,"position":4},"title":"Grayhat’s NCPL (Noise-Cancelling Passive Loop) antenna “tweak”","author":"Thomas","date":"August 15, 2021","format":false,"excerpt":"Many thanks to SWLing Post contributor, Grayhat, who shares the following modification he made to a Noise-Cancelling Passive Loop antenna last year. He's kindly allowed me to share his notes here, but apologized that at the time, he didn't take photos of the project along the way and recycled many\u2026","rel":"","context":"In "Antennas"","block_context":{"text":"Antennas","link":"https:\/\/swling.com\/blog\/category\/antennas\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2021\/08\/moebius.jpeg?resize=350%2C200&ssl=1","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2021\/08\/moebius.jpeg?resize=350%2C200&ssl=1 1x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2021\/08\/moebius.jpeg?resize=525%2C300&ssl=1 1.5x"},"classes":[]},{"id":42856,"url":"https:\/\/swling.com\/blog\/2020\/04\/hack-a-broken-vga-cable-to-make-a-binocular-ferrite-cores-for-your-ncpl-antenna\/","url_meta":{"origin":23472,"position":5},"title":"Hack a broken VGA cable to make a binocular ferrite cores for your NCPL antenna","author":"Thomas","date":"April 15, 2020","format":false,"excerpt":"Many thanks to Oscar (EA3IBC) who shares this simple hack. I've gotten quite a few emails from Post readers telling me that the only thing holding them back from building a NCPL antenna is the BN-73-302 binocular ferrite core needed for the 1:1 Balun. While so much of the world\u2026","rel":"","context":"In "Antennas"","block_context":{"text":"Antennas","link":"https:\/\/swling.com\/blog\/category\/antennas\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2020\/04\/NCPL-Noise-Cancelling-Passive-Loop-Antenna-970x1024.jpg?resize=350%2C200&ssl=1","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2020\/04\/NCPL-Noise-Cancelling-Passive-Loop-Antenna-970x1024.jpg?resize=350%2C200&ssl=1 1x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2020\/04\/NCPL-Noise-Cancelling-Passive-Loop-Antenna-970x1024.jpg?resize=525%2C300&ssl=1 1.5x"},"classes":[]}],"jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/swling.com\/blog\/wp-json\/wp\/v2\/posts\/23472","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/swling.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/swling.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/swling.com\/blog\/wp-json\/wp\/v2\/users\/15"}],"replies":[{"embeddable":true,"href":"https:\/\/swling.com\/blog\/wp-json\/wp\/v2\/comments?post=23472"}],"version-history":[{"count":0,"href":"https:\/\/swling.com\/blog\/wp-json\/wp\/v2\/posts\/23472\/revisions"}],"wp:attachment":[{"href":"https:\/\/swling.com\/blog\/wp-json\/wp\/v2\/media?parent=23472"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/swling.com\/blog\/wp-json\/wp\/v2\/categories?post=23472"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/swling.com\/blog\/wp-json\/wp\/v2\/tags?post=23472"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}