{"id":42918,"date":"2020-04-20T07:59:29","date_gmt":"2020-04-20T11:59:29","guid":{"rendered":"https:\/\/swling.com\/blog\/?p=42918"},"modified":"2020-04-20T07:59:29","modified_gmt":"2020-04-20T11:59:29","slug":"more-about-hacking-vga-cables-to-make-binocular-ferrite-cores","status":"publish","type":"post","link":"https:\/\/swling.com\/blog\/2020\/04\/more-about-hacking-vga-cables-to-make-binocular-ferrite-cores\/","title":{"rendered":"More about hacking VGA cables to make binocular ferrite cores"},"content":{"rendered":"

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

A few days ago, we posted an a short article showing how Oscar hacked a VGA cable<\/a> to make a binocular ferrite core for his homebrew NCPL\/Youloop antenna<\/a>. Many thanks to SWLing Post<\/em> contributor, Grayhat, who explored this clever hack a little further:<\/p>\n

Hi Thomas, Having some time in my hands Sunday afternoon I decided to try pulling out the ferrite chokes from a VGA cable I had around, and while doing so, I decided to coarsely document the process with some pics.<\/p><\/blockquote>\n

\"\"<\/a>

Figure 1<\/p><\/div>\n

The first thing to do is use a cutter to carefully cut around the “washer” shaped plastic at the connector end of the choke (fig.1, #1,#2, #3 above), then on the same side, after cutting the plastic also cut the inner conductors (fig.1, #1).<\/p>\n

Move to the other side of the choke, gently cut around the “washer” w\/o cutting the inner conductors, now pull the cable to extract it from the choke (fig.1, #3), repeat the process for the other choke.<\/p>\n

Now look at the “cans” containing the chokes, one side of those will show a “cap” (fig.1, #4), insert a small screwdriver into the center hole and gently ply to one side to raise the cap and extract it (fig.2, #1).<\/p><\/blockquote>\n

\"\"<\/a>

Figure 2<\/p><\/div>\n

The result will be as in fig.2, where #1 is the closing cap, #2 is the ferrite choke and #3 is the “can” containing the choke. Repeat the process and you’ll have two ferrite chokes as shown in fig.3 (the VGA connector is there to give an idea of the dimensions):<\/p><\/blockquote>\n

\"\"<\/a>

Figure 3<\/p><\/div>\n

At this point, use some tape (duct tape will be a better idea, I used clear tape just to make an example) to tie the two ferrites together as in fig.4 and you’ll have your “binocular ferrite”:<\/p><\/blockquote>\n

\"\"<\/a>

Figure 4<\/p><\/div>\n

Willing to use whatever you have there to wind the transformer, you may now extract the tiny insulated wires from the VGA cable (fig.1, #3, see wires) and use them for the windings.<\/p>\n

Notice that other cables may use different choke “cans” which may need to cut a larger portion around the flat faces at the ends. But remember that in any case, those are just “snap-in” cans containing the ferrites, so with a bit of attention and patience, it shouldn’t be difficult extracting the ferrites.<\/p>\n

Based on a little online research, it sounds like the ferrites used to choke the VGA cables (HDMI ones too) are generally type #31.<\/p>\n

Looking at some #31 datasheets it appears that while #73 is works fine at frequencies below 50MHz, the #31 is best suited for the 1-300MHz range<\/a>.<\/p>\n

This means that #31 won’t be the best pick for mediumwave, although if one doesn’t have another choice… well, go for that! Also notice that the ferrite permeability is different:1500 for #31 and 2500 for #73. This means that we’ll need to increase the number of windings to achieve acceptable signal transfer, otherwise the transformer loss will make our antenna deaf.<\/p>\n

One might try increasing the number of windings to say 8:8 or 16:16; as long as the winding
\nratio will remain the same, there won’t be problems (although the resulting bandwidth will become narrower).<\/p><\/blockquote>\n

Thanks for documenting and sharing this, Grayhat! Since most of us have more time on our hands at home, I think it would be worth experimenting with the number of windings to see how it affects the antenna performance. That’s a clever thought, too, to use the VGA wires to wind the Balun. As long as the cable is long enough for the amount of turns, it’s certainly the most efficient use of resources!<\/p>\n","protected":false},"excerpt":{"rendered":"

A few days ago, we posted an a short article showing how Oscar hacked a VGA cable to make a binocular ferrite core for his homebrew NCPL\/Youloop antenna. Many thanks to SWLing Post contributor, Grayhat, who explored this clever hack a little further: Hi Thomas, Having some time in my hands Sunday afternoon I decided […]<\/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":[3607,545,627,3,43,158],"tags":[8353,4339,8440,7880,4359,4357,8413,8412,8439,157],"class_list":["post-42918","post","type-post","status-publish","format-standard","hentry","category-antennas","category-ham-radio","category-how-to","category-news","category-shortwave-radio","category-software-defined-radio","tag-airspy-youloop","tag-am-passive-loop-antenna","tag-binocular-ferrite-core","tag-grayhat","tag-homebrew-mag-loop-antenna","tag-mag-loop-antennas","tag-ncpl-antenna","tag-noise-cancelling-passive-loop-antenna","tag-oscar-ea3ibc","tag-sdr"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"","jetpack_shortlink":"https:\/\/wp.me\/pn3uc-bae","jetpack-related-posts":[{"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":42918,"position":0},"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":[]},{"id":44834,"url":"https:\/\/swling.com\/blog\/2020\/08\/bruce-compares-two-homebrew-ncpl-antennas-to-the-airspy-youloop\/","url_meta":{"origin":42918,"position":1},"title":"Bruce compares two homebrew NCPL antennas to the Airspy Youloop","author":"Thomas","date":"August 16, 2020","format":false,"excerpt":"Many thanks to SWLing Post contributor, Bruce (VE3EAR), who writes: I decided that more testing of the Noise-Cancelling Passive Loop (YouLoop) antenna was needed, but I wanted to start with a clean page. I built two identical loops using some 3\/8 inch heliax scraps I had on hand. Both are\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\/08\/YouLoop2.jpeg?resize=350%2C200&ssl=1","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2020\/08\/YouLoop2.jpeg?resize=350%2C200&ssl=1 1x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2020\/08\/YouLoop2.jpeg?resize=525%2C300&ssl=1 1.5x"},"classes":[]},{"id":43158,"url":"https:\/\/swling.com\/blog\/2020\/05\/patrizios-simple-homebrew-ncpl-antenna\/","url_meta":{"origin":42918,"position":2},"title":"Patrizio’s simple homebrew NCPL antenna","author":"Thomas","date":"May 7, 2020","format":false,"excerpt":"Many thanks to SWLing Post contributor, Patrizio Cardelli, who writes: I'm Patrizio (SWL I - 5184 \/AN) from Riva del Garda, Italy. A few days ago, I built a Noise-Cancelling Passive Loop (NCPL) antenna. I built the 1:1 balun with a couple of ferrite 175 - 285. I got a\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\/05\/Screen-Shot-2020-05-07-at-7.35.59-AM-e1588851426131.jpeg?resize=350%2C200&ssl=1","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2020\/05\/Screen-Shot-2020-05-07-at-7.35.59-AM-e1588851426131.jpeg?resize=350%2C200&ssl=1 1x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2020\/05\/Screen-Shot-2020-05-07-at-7.35.59-AM-e1588851426131.jpeg?resize=525%2C300&ssl=1 1.5x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2020\/05\/Screen-Shot-2020-05-07-at-7.35.59-AM-e1588851426131.jpeg?resize=700%2C400&ssl=1 2x"},"classes":[]},{"id":42595,"url":"https:\/\/swling.com\/blog\/2020\/04\/diy-how-to-build-a-noise-cancelling-passive-loop-ncpl-antenna\/","url_meta":{"origin":42918,"position":3},"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":48622,"url":"https:\/\/swling.com\/blog\/2021\/04\/giuseppe-is-impressed-with-the-performance-of-his-homebrew-passive-loop-antenna\/","url_meta":{"origin":42918,"position":4},"title":"Giuseppe is impressed with the performance of his homebrew passive loop antenna","author":"Thomas","date":"April 22, 2021","format":false,"excerpt":"Many thanks to\u00a0SWLing Post\u00a0contributor, Giuseppe Morl\u00e8 (IZ0GZW), who shares the following: Dear Thomas, I'm Giuseppe Morl\u00e8 from central Italy, the Tyrrhenian Sea, Formia. Today I tested my noise canceling loop inside the radio station by comparing it to the crossed loops. Again, like my medium wave T Ferrite, this loop\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\/2021\/04\/Giuseppe.jpg?resize=350%2C200&ssl=1","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2021\/04\/Giuseppe.jpg?resize=350%2C200&ssl=1 1x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2021\/04\/Giuseppe.jpg?resize=525%2C300&ssl=1 1.5x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2021\/04\/Giuseppe.jpg?resize=700%2C400&ssl=1 2x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2021\/04\/Giuseppe.jpg?resize=1050%2C600&ssl=1 3x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2021\/04\/Giuseppe.jpg?resize=1400%2C800&ssl=1 4x"},"classes":[]},{"id":42815,"url":"https:\/\/swling.com\/blog\/2020\/04\/beating-the-quarantine-blues-readers-build-homebrew-ncpl-antennas\/","url_meta":{"origin":42918,"position":5},"title":"Beating the Quarantine Blues: Readers build homebrew NCPL antennas","author":"Thomas","date":"April 13, 2020","format":false,"excerpt":"Recently, I published a step-by-step guide on building a Noise-Cancelling Passive Loop (NCPL) antenna. 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If so, my apologies!] I think this passive loop antenna project has been so appealing because (1.) most of us around 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\/IMG20200408142726-197x300.jpeg?resize=350%2C200&ssl=1","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2020\/04\/IMG20200408142726-197x300.jpeg?resize=350%2C200&ssl=1 1x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2020\/04\/IMG20200408142726-197x300.jpeg?resize=525%2C300&ssl=1 1.5x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2020\/04\/IMG20200408142726-197x300.jpeg?resize=700%2C400&ssl=1 2x"},"classes":[]}],"jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/swling.com\/blog\/wp-json\/wp\/v2\/posts\/42918","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=42918"}],"version-history":[{"count":0,"href":"https:\/\/swling.com\/blog\/wp-json\/wp\/v2\/posts\/42918\/revisions"}],"wp:attachment":[{"href":"https:\/\/swling.com\/blog\/wp-json\/wp\/v2\/media?parent=42918"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/swling.com\/blog\/wp-json\/wp\/v2\/categories?post=42918"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/swling.com\/blog\/wp-json\/wp\/v2\/tags?post=42918"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}