{"id":2247,"date":"2026-06-01T17:17:36","date_gmt":"2026-06-01T17:17:36","guid":{"rendered":"https:\/\/aegir-ran.com\/?p=2247"},"modified":"2026-06-01T17:17:38","modified_gmt":"2026-06-01T17:17:38","slug":"a-portable-marine-single-side-band-radio","status":"publish","type":"post","link":"https:\/\/aegir-ran.com\/index.php\/2026\/06\/01\/a-portable-marine-single-side-band-radio\/","title":{"rendered":"A Portable Marine Single Side-Band Radio"},"content":{"rendered":"\n

On S\/V Aegir-Ran I had a 1990s era ICOM M-710 SSB radio. I had trouble getting it to work properly. The problem seemed to be intermittent. I acquired a second M-710 radio and exchanges some components (the M-710 radio at AT-130 auto tuner, etc.), but this did not solve the problem. The original counterpoise ground was a ring of copper foil built into the hull. Later, I tried a KISS Counterpoise Kit. Neither fixed the problem. The original antenna was the insulated backstay, but when I installed new standing rigging I replaced it with a GAM antenna that slipped over one of the backstays. I lost all of this equipment with S\/V Aegir-Ran. Recently, I acquired a ICOM M-802 and an AT-140. The M-802 is of a different design, with the radio separate from a remote control (RC-25) head. I am interested in installing the M-802\/AT-140 temporarily on S\/V Saint Brendan, in part so I can take it with me when I move own to the next boat, and in part so I do not have to learn a new radio. The M-802 is the last ICOM SSB radio built that does not have a GPS, so it is suitable for the Golden Globe Race.<\/p>\n\n\n\n

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The idea was to combine the M-802 and AT-140 into a single package that is easily mounted and removed. Note the AT-140 must be mounted close to the antenna.<\/p>\n\n\n\n

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I did not want to modify any of the cabling so it was necessary to locate the somewhat obscure connects that are used on the units. The flat 4-pin connector on the AT-140 requires a JReady ST6417 Standard 0.093 Connector that I found on Amazon. The corresponding plug on the M-802 is a more rare JST XMP-06V connector, which I found on AliExpress. The circular 8-pin Mini-DIN Connector on the M-802 was addressed with a Plinkwirekb Male-to Female extension on Amazon. The panel-mounted 3.5 mm (1\/8″) min jack was wound on Amazon. Finally, the panel-mounted Anderson SB50 Power Connector was also found on Amazon.<\/p>\n\n\n\n

With all of labeling sorted out, I turned to designing a case that would combine all of the components. I Used Fusion360 to prepare DXF files that were submitted to SendCutSend for manufacturing.<\/p>\n\n\n\n

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For the Counterpoise I went old school (and reliable), a porous bronze grounding plate. Unfortunately, a plate of sufficient size for SSB is quite expensive ($1000), but I found a Marino Guest Danaplate 4018 (18″ x 6″) on eBay for $120. Unfortunately, that plate was missing the special gold-plated grounding bolt. I found a replacement bolt (P-12D37, $18) and nuts (P-13A2A, $4 each x 2).<\/p>\n\n\n\n

I have been giving some thought to the antenna. In keeping with the idea of a portable system, I am simply going with a single strand of GTO-15 wire that is secured to the backstay with dual loop zip-ties I will use small bits of heat-shrink tubing to create stops so the zip-ties do not slip as I just the GTO-15. up the backstay. The AT-140 is intended for 7 m (23′) or longer antenna. The backstay on a Tartan 34C is 43-44′. I intend to use an active length of 35-37′ for the GTO-15 antenna. This will avoid any impedance problems at high frequency. <\/p>\n\n\n\n

I expect the ICOM radio case to be mounted in the quarter berth, maybe in the space that houses the steering quadrant. Accordingly, all electrical cables will be run there (antenna, counterpoise ground, power, RC-25 and SP-24 cables). The quick-release bracket means that basically I simply need to unplug five cables and undo two straps to remove the M-802\/AT-140 unit.<\/p>\n\n\n\n

The SSB radio I received did not have the mounting brackets for the remote (RC-25) and speaker (SP-24). While I could find the bracket for the SP-24 on eBay, I could not find one for the RC-25. Accordingly, I manufactured brackets:<\/p>\n\n\n\n

\"\"<\/figure>\n","protected":false},"excerpt":{"rendered":"

On S\/V Aegir-Ran I had a 1990s era ICOM M-710 SSB radio. I had trouble getting it to work properly. The problem seemed to be intermittent. I acquired a second M-710 radio and exchanges some components (the M-710 radio at AT-130 auto tuner, etc.), but this did not solve the problem. The original counterpoise ground … <\/p>\n

Continue reading “A Portable Marine Single Side-Band Radio”<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"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","enabled":false},"version":2}},"categories":[1],"tags":[21],"class_list":["post-2247","post","type-post","status-publish","format-standard","hentry","category-uncategorized","tag-equipment"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"jetpack_likes_enabled":false,"_links":{"self":[{"href":"https:\/\/aegir-ran.com\/index.php\/wp-json\/wp\/v2\/posts\/2247","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/aegir-ran.com\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/aegir-ran.com\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/aegir-ran.com\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/aegir-ran.com\/index.php\/wp-json\/wp\/v2\/comments?post=2247"}],"version-history":[{"count":1,"href":"https:\/\/aegir-ran.com\/index.php\/wp-json\/wp\/v2\/posts\/2247\/revisions"}],"predecessor-version":[{"id":2252,"href":"https:\/\/aegir-ran.com\/index.php\/wp-json\/wp\/v2\/posts\/2247\/revisions\/2252"}],"wp:attachment":[{"href":"https:\/\/aegir-ran.com\/index.php\/wp-json\/wp\/v2\/media?parent=2247"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/aegir-ran.com\/index.php\/wp-json\/wp\/v2\/categories?post=2247"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/aegir-ran.com\/index.php\/wp-json\/wp\/v2\/tags?post=2247"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}