{"id":443,"date":"2021-04-07T13:23:51","date_gmt":"2021-04-07T03:23:51","guid":{"rendered":"http:\/\/www.vk1zdj.net\/?p=443"},"modified":"2021-04-07T13:23:51","modified_gmt":"2021-04-07T03:23:51","slug":"yaesu-fc30-tuner-protocol","status":"publish","type":"post","link":"http:\/\/www.vk1zdj.net\/?p=443","title":{"rendered":"Yaesu FC30 Tuner Protocol"},"content":{"rendered":"\n<p>Or how I (almost) interfaced an Yaesu FT-891 radio to an Icom tuner.<\/p>\n\n\n\n<p>I recently decided to replace my Icom IC708G in the car, as it had a weird ALC fault on transmit.  It is afterall, a radio that came out in 1997, making it approximately 24 years old.  I reviewed what was available in the field, and settled on the Yaesu FT-891.<\/p>\n\n\n\n<p>I selected the FC-50 tuner as a suitable tuner, and was dismayed that my research didn&#8217;t reveal that it is useless.  It can only tune within a 3:1 range, so is simply not suitable for the 3m helical whip I use on the back of the Xtrail.<\/p>\n\n\n\n<p>Not to worry,  I already have an Icom AH-4 tuner in the car, and it eats the tuning job for breakfast.  So &#8211; How to plug a round plug into a square hole (Kind of literally &#8211; The Yaesu is round Mini DIN8, while the Icom is a rectangular Molex 4 pin)?<\/p>\n\n\n\n<h2>FC-50 Physical Connection<\/h2>\n\n\n\n<p>The first step was to break out the cable between the FT-891 and the FC-50.  A little research showed me that the cable had the following pinout;<\/p>\n\n\n\n<ul><li>Pin 1 &#8211; +13V<\/li><li>Pin 2 &#8211; TX Gnd (Pulled low by the radio on TX)<\/li><li>Pin 3 &#8211; Ground<\/li><li>Pin 4 &#8211; TX Data (TTL Level)<\/li><li>Pin 5 &#8211; RX Data (TTL Level)<\/li><li>Pin 6 &#8211; Tuner presence detection (Grounded by the tuner)<\/li><li>Pin 7 &#8211; Reset (Pulled high by the radio)<\/li><li>Pin 8 &#8211; TX INH &#8211; (Grounded by the tuner)<\/li><\/ul>\n\n\n\n<figure class=\"wp-block-image size-large\"><a href=\"http:\/\/www.vk1zdj.net\/wp-content\/uploads\/2021\/04\/8PinMiniDin.png\"><img decoding=\"async\" loading=\"lazy\" width=\"764\" height=\"660\" src=\"http:\/\/www.vk1zdj.net\/wp-content\/uploads\/2021\/04\/8PinMiniDin.png\" alt=\"\" class=\"wp-image-442\" srcset=\"http:\/\/www.vk1zdj.net\/wp-content\/uploads\/2021\/04\/8PinMiniDin.png 764w, http:\/\/www.vk1zdj.net\/wp-content\/uploads\/2021\/04\/8PinMiniDin-300x259.png 300w, http:\/\/www.vk1zdj.net\/wp-content\/uploads\/2021\/04\/8PinMiniDin-80x69.png 80w\" sizes=\"(max-width: 764px) 100vw, 764px\" \/><\/a><\/figure>\n\n\n\n<p>Data is sent at 4800 baud, so the signals were broken out with a piece of veroboard and examined with a scope and an Ardiuno monitoring the data lines.<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><a href=\"http:\/\/www.vk1zdj.net\/wp-content\/uploads\/2021\/04\/Breakout.png\"><img decoding=\"async\" loading=\"lazy\" width=\"630\" height=\"806\" src=\"http:\/\/www.vk1zdj.net\/wp-content\/uploads\/2021\/04\/Breakout.png\" alt=\"\" class=\"wp-image-438\" srcset=\"http:\/\/www.vk1zdj.net\/wp-content\/uploads\/2021\/04\/Breakout.png 630w, http:\/\/www.vk1zdj.net\/wp-content\/uploads\/2021\/04\/Breakout-234x300.png 234w, http:\/\/www.vk1zdj.net\/wp-content\/uploads\/2021\/04\/Breakout-80x102.png 80w\" sizes=\"(max-width: 630px) 100vw, 630px\" \/><\/a><\/figure>\n\n\n\n<p>I had a massive step up from research that was done by John Price \u2013 WA2FZW, in a document that he published in the files section of the FT891 Groups page (FT-891 to MFJ-939Y Tuner Interface Test Box).<\/p>\n\n\n\n<h2>Yaesu Logical Protocol<\/h2>\n\n\n\n<p>Pressing the TUNE button on the radio starts the following process when communicating with the FC-50;<\/p>\n\n\n\n<figure class=\"wp-block-table is-style-regular\"><table><tbody><tr><td><strong>Radio<\/strong><\/td><td><strong>Tuner<\/strong><\/td><td><strong>Function<\/strong><\/td><\/tr><tr><td>0xFF<\/td><td><\/td><td>Wake up tuner (delay of 50mS required)<\/td><\/tr><tr><td>0xF1<\/td><td><\/td><td>Set Frequency to zero<\/td><\/tr><tr><td>0x00<\/td><td><\/td><td><\/td><\/tr><tr><td>0x00<\/td><td><\/td><td><\/td><\/tr><tr><td><\/td><td>0xA1<\/td><td>Tuner Tuning<\/td><\/tr><tr><td>0xFF<\/td><td><\/td><td>Wake tuner<\/td><\/tr><tr><td>0xF2<\/td><td><\/td><td>Set Frequency<\/td><\/tr><tr><td>0x14<\/td><td><\/td><td><\/td><\/tr><tr><td>0x03<\/td><td><\/td><td>14.03Mhz<\/td><\/tr><tr><td><\/td><td>0xA0<\/td><td>Frequency Ack &#8211; Starts tuning<\/td><\/tr><tr><td><\/td><td>0xA1<\/td><td>Tuner finished tuning<\/td><\/tr><tr><td><\/td><td><\/td><td><\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<p> <\/p>\n\n\n\n<h2>AH-4 Physical Connection<\/h2>\n\n\n\n<p>The AH-4 uses a 4 pin Molex<\/p>\n\n\n\n<ul><li>Pin 1 &#8211; Key &#8211; Output from tuner<\/li><li>Pin 2 &#8211; Start &#8211; Output from radio<\/li><li>Pin 3 &#8211; +12V<\/li><li>Pin 4 &#8211; Gnd<\/li><\/ul>\n\n\n\n<figure class=\"wp-block-image size-large\"><a href=\"http:\/\/www.vk1zdj.net\/wp-content\/uploads\/2021\/04\/AH-4Pinout-1.png\"><img decoding=\"async\" loading=\"lazy\" width=\"321\" height=\"332\" src=\"http:\/\/www.vk1zdj.net\/wp-content\/uploads\/2021\/04\/AH-4Pinout-1.png\" alt=\"\" class=\"wp-image-451\" srcset=\"http:\/\/www.vk1zdj.net\/wp-content\/uploads\/2021\/04\/AH-4Pinout-1.png 321w, http:\/\/www.vk1zdj.net\/wp-content\/uploads\/2021\/04\/AH-4Pinout-1-290x300.png 290w, http:\/\/www.vk1zdj.net\/wp-content\/uploads\/2021\/04\/AH-4Pinout-1-80x83.png 80w\" sizes=\"(max-width: 321px) 100vw, 321px\" \/><\/a><\/figure>\n\n\n\n<h2>Yaesu Logical Protocol<\/h2>\n\n\n\n<p>To tune, the radio starts by asserting the &lt;Start> line.  Approximately 300mS later, the tuner asserts &lt;key> &#8211; This causes the radio output to keyup at a <strong>reduced power level<\/strong>.  (This bit is important)<\/p>\n\n\n\n<p>The AH-4 then tunes, and uses &lt;key> to let the radio know if the tuning was successful.  This is an example of a successful tune.<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><a href=\"http:\/\/www.vk1zdj.net\/wp-content\/uploads\/2021\/04\/AH-4-TuneOk.png\"><img decoding=\"async\" loading=\"lazy\" width=\"536\" height=\"162\" src=\"http:\/\/www.vk1zdj.net\/wp-content\/uploads\/2021\/04\/AH-4-TuneOk.png\" alt=\"\" class=\"wp-image-449\" srcset=\"http:\/\/www.vk1zdj.net\/wp-content\/uploads\/2021\/04\/AH-4-TuneOk.png 536w, http:\/\/www.vk1zdj.net\/wp-content\/uploads\/2021\/04\/AH-4-TuneOk-300x91.png 300w, http:\/\/www.vk1zdj.net\/wp-content\/uploads\/2021\/04\/AH-4-TuneOk-80x24.png 80w\" sizes=\"(max-width: 536px) 100vw, 536px\" \/><\/a><\/figure>\n\n\n\n<p>If tuning fails, the AH-4 returns an extra 20ms wide negative pulse on the &lt;key> line<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><a href=\"http:\/\/www.vk1zdj.net\/wp-content\/uploads\/2021\/04\/AH-4-TuneFail.png\"><img decoding=\"async\" loading=\"lazy\" width=\"660\" height=\"162\" src=\"http:\/\/www.vk1zdj.net\/wp-content\/uploads\/2021\/04\/AH-4-TuneFail.png\" alt=\"\" class=\"wp-image-448\" srcset=\"http:\/\/www.vk1zdj.net\/wp-content\/uploads\/2021\/04\/AH-4-TuneFail.png 660w, http:\/\/www.vk1zdj.net\/wp-content\/uploads\/2021\/04\/AH-4-TuneFail-300x74.png 300w, http:\/\/www.vk1zdj.net\/wp-content\/uploads\/2021\/04\/AH-4-TuneFail-80x20.png 80w\" sizes=\"(max-width: 660px) 100vw, 660px\" \/><\/a><\/figure>\n\n\n\n<h2>Tune Power<\/h2>\n\n\n\n<p>And this is where we hit a roadblock&#8230;..   The AH-4 is designed to tune with a maximum input power of 10 Watts.   The Yaesu will merrily output a 50W CW level while tuning.   <\/p>\n\n\n\n<p>This may be an issue.<\/p>\n\n\n\n<p>More later&#8230;..<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Or how I (almost) interfaced an Yaesu FT-891 radio to an Icom tuner. I recently decided to replace my Icom IC708G in the car, as it had a weird ALC fault on transmit. It is afterall, a radio&#8230; <\/p>\n","protected":false},"author":1,"featured_media":441,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"inline_featured_image":false},"categories":[6,9,5],"tags":[],"jetpack_featured_media_url":"http:\/\/www.vk1zdj.net\/wp-content\/uploads\/2021\/04\/Tuning.png","_links":{"self":[{"href":"http:\/\/www.vk1zdj.net\/index.php?rest_route=\/wp\/v2\/posts\/443"}],"collection":[{"href":"http:\/\/www.vk1zdj.net\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/www.vk1zdj.net\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/www.vk1zdj.net\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/www.vk1zdj.net\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=443"}],"version-history":[{"count":5,"href":"http:\/\/www.vk1zdj.net\/index.php?rest_route=\/wp\/v2\/posts\/443\/revisions"}],"predecessor-version":[{"id":452,"href":"http:\/\/www.vk1zdj.net\/index.php?rest_route=\/wp\/v2\/posts\/443\/revisions\/452"}],"wp:featuredmedia":[{"embeddable":true,"href":"http:\/\/www.vk1zdj.net\/index.php?rest_route=\/wp\/v2\/media\/441"}],"wp:attachment":[{"href":"http:\/\/www.vk1zdj.net\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=443"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/www.vk1zdj.net\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=443"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/www.vk1zdj.net\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=443"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}