{"id":60019,"date":"2024-06-17T14:53:28","date_gmt":"2024-06-17T18:53:28","guid":{"rendered":"https:\/\/swling.com\/blog\/?p=60019"},"modified":"2024-06-17T14:53:28","modified_gmt":"2024-06-17T18:53:28","slug":"can-you-help-dan-identify-this-mystery-interval-signal","status":"publish","type":"post","link":"https:\/\/swling.com\/blog\/2024\/06\/can-you-help-dan-identify-this-mystery-interval-signal\/","title":{"rendered":"Can you help Dan identify this mystery interval signal?"},"content":{"rendered":"

\"Photo<\/a>Many thanks to Dan Greenall, one of our dedicated Shortwave Radio Audio Archive<\/a> contributors, who writes:<\/strong><\/p>\n

Hi Thomas<\/p>\n

I was going over a few of my old cassettes today and discovered what seems to be an interval signal, but I cannot seem to place it.<\/p>\n

Recording:<\/h3>\nhttps:\/\/swling.com\/blog\/wp-content\/uploads\/2024\/06\/Mystery-Interval-Signal-1971.mp3<\/a><\/audio>\n

Unfortunately, all I can tell you is that it was made sometime in 1971.<\/p>\n

I’ve done a little checking with Interval Signals Online but no luck so far. The recording is right at the end of a cassette and you can hear the tape run out abruptly, so no ID, language or frequency info is available.<\/p>\n

[…]Any ideas about the mystery IS?<\/p>\n

73<\/p>\n

Readers: If you can help Dan positively identify this interval signal, please comment!<\/strong><\/p>\n","protected":false},"excerpt":{"rendered":"

Many thanks to Dan Greenall, one of our dedicated Shortwave Radio Audio Archive contributors, who writes: Hi Thomas I was going over a few of my old cassettes today and discovered what seems to be an interval signal, but I cannot seem to place it. Recording: Unfortunately, all I can tell you is that it […]<\/p>\n","protected":false},"author":15,"featured_media":0,"comment_status":"open","ping_status":"closed","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":[3,305,746,43],"tags":[10271,94,5448],"class_list":["post-60019","post","type-post","status-publish","format-standard","hentry","category-news","category-nostalgia","category-recordings","category-shortwave-radio","tag-dan-greenall","tag-interval-signals","tag-mystery-signals"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"","jetpack_shortlink":"https:\/\/wp.me\/pn3uc-fC3","jetpack-related-posts":[{"id":57327,"url":"https:\/\/swling.com\/blog\/2023\/07\/radio-botswana-barnyard-sounds-mystery\/","url_meta":{"origin":60019,"position":0},"title":"Radio Botswana barnyard sounds mystery","author":"Thomas","date":"July 23, 2023","format":false,"excerpt":"Many thanks to SWLing Post and SRAA contributor, Dan Greenall, who shares the following off-air shortwave radio recording and writes: In all of the recordings of Radio Botswana\u2019s famous barnyard interval signal I can find, the barnyard sounds are accompanied by the sound of cowbells. There is usually a rooster\u2026","rel":"","context":"In "News"","block_context":{"text":"News","link":"https:\/\/swling.com\/blog\/category\/news\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2015\/08\/HalliDial.jpg?resize=350%2C200&ssl=1","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2015\/08\/HalliDial.jpg?resize=350%2C200&ssl=1 1x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2015\/08\/HalliDial.jpg?resize=525%2C300&ssl=1 1.5x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2015\/08\/HalliDial.jpg?resize=700%2C400&ssl=1 2x"},"classes":[]},{"id":42154,"url":"https:\/\/swling.com\/blog\/2020\/02\/mystery-solved-readers-identify-curious-interval-signal\/","url_meta":{"origin":60019,"position":1},"title":"Mystery Solved: Readers identify curious interval signal","author":"Thomas","date":"February 24, 2020","format":false,"excerpt":"Yesterday, we published a post asking SWLing Readers to help Brian (W9IND) identify an elusive interval signal (click here to read that post). We received dozens of replies--thank you so much! Many readers immediately identified the tune as some sort of utility station placeholder for Point To Point communications. Turns\u2026","rel":"","context":"In "News"","block_context":{"text":"News","link":"https:\/\/swling.com\/blog\/category\/news\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2020\/02\/PTT-Habana-Cuba-VErification.jpg?resize=350%2C200&ssl=1","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2020\/02\/PTT-Habana-Cuba-VErification.jpg?resize=350%2C200&ssl=1 1x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2020\/02\/PTT-Habana-Cuba-VErification.jpg?resize=525%2C300&ssl=1 1.5x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2020\/02\/PTT-Habana-Cuba-VErification.jpg?resize=700%2C400&ssl=1 2x"},"classes":[]},{"id":42146,"url":"https:\/\/swling.com\/blog\/2020\/02\/help-brian-identify-this-1970s-era-interval-signal\/","url_meta":{"origin":60019,"position":2},"title":"Help Brian identify this 1970s era interval signal","author":"Thomas","date":"February 23, 2020","format":false,"excerpt":"[Mystery solved! Click here to read the update.] Many thanks to SWLing Post contributor, Brian (W9IND), who writes: I want to thank you for stirring a memory that I never thought I\u2019d relive \u2013 even though it still doesn\u2019t solve the mystery of what the heck I was listening to\u2026","rel":"","context":"In "News"","block_context":{"text":"News","link":"https:\/\/swling.com\/blog\/category\/news\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2015\/09\/SX-99-Dial-Nar.jpg?resize=350%2C200&ssl=1","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2015\/09\/SX-99-Dial-Nar.jpg?resize=350%2C200&ssl=1 1x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2015\/09\/SX-99-Dial-Nar.jpg?resize=525%2C300&ssl=1 1.5x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2015\/09\/SX-99-Dial-Nar.jpg?resize=700%2C400&ssl=1 2x"},"classes":[]},{"id":65726,"url":"https:\/\/swling.com\/blog\/2026\/04\/bbc-interval-signals-then-and-now\/","url_meta":{"origin":60019,"position":3},"title":"BBC Interval Signals \u2013 Then and Now","author":"Thomas","date":"April 3, 2026","format":false,"excerpt":"by Dan Greenall A half century ago, the BBC World Service used a number of different interval signals. \u00a0 A few minutes prior to the start of a broadcast, a recognizable, often repeating tune would be played that would enable listeners to more easily locate the BBC in a crowded\u2026","rel":"","context":"In "News"","block_context":{"text":"News","link":"https:\/\/swling.com\/blog\/category\/news\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2026\/04\/BBC-Ascension-1970-front.jpeg?resize=350%2C200&ssl=1","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2026\/04\/BBC-Ascension-1970-front.jpeg?resize=350%2C200&ssl=1 1x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2026\/04\/BBC-Ascension-1970-front.jpeg?resize=525%2C300&ssl=1 1.5x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2026\/04\/BBC-Ascension-1970-front.jpeg?resize=700%2C400&ssl=1 2x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2026\/04\/BBC-Ascension-1970-front.jpeg?resize=1050%2C600&ssl=1 3x"},"classes":[]},{"id":221,"url":"https:\/\/swling.com\/blog\/2011\/07\/between-broadcasts-exploring-interval-signals\/","url_meta":{"origin":60019,"position":4},"title":"Between Broadcasts-Exploring Interval Signals","author":"Thomas","date":"July 7, 2011","format":false,"excerpt":"Lately, I've been listening to a plethora of shortwave broadcasts as I'm about to review several new radios. I've noted so many great interval signals that are still in use.\u00a0The following is a reprise of a previous post--from over two years ago--about interval signals. If you've never heard of interval\u2026","rel":"","context":"In "Articles"","block_context":{"text":"Articles","link":"https:\/\/swling.com\/blog\/category\/articles\/"},"img":{"alt_text":"Analog Radio Dial","src":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/\/2009\/05\/swdial.jpg?resize=350%2C200","width":350,"height":200},"classes":[]},{"id":42227,"url":"https:\/\/swling.com\/blog\/2020\/03\/lets-solve-another-interval-signal-mystery\/","url_meta":{"origin":60019,"position":5},"title":"Let’s solve another interval signal mystery!","author":"Thomas","date":"March 8, 2020","format":false,"excerpt":"Last month, we published\u00a0a post\u00a0asking\u00a0SWLing Readers to help Brian (W9IND) identify an elusive interval signal. Turns out, the interval signal belonged to the Voice Mirror of the PTT Habana, Cuba station. This month, SWLing Post contributor, David Crawford is asking for help to ID another interval signal which likely belongs\u2026","rel":"","context":"In "News"","block_context":{"text":"News","link":"https:\/\/swling.com\/blog\/category\/news\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2020\/03\/Push-button-phone-cropped-e1583684071445.jpg?resize=350%2C200&ssl=1","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2020\/03\/Push-button-phone-cropped-e1583684071445.jpg?resize=350%2C200&ssl=1 1x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2020\/03\/Push-button-phone-cropped-e1583684071445.jpg?resize=525%2C300&ssl=1 1.5x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2020\/03\/Push-button-phone-cropped-e1583684071445.jpg?resize=700%2C400&ssl=1 2x"},"classes":[]}],"jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/swling.com\/blog\/wp-json\/wp\/v2\/posts\/60019","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=60019"}],"version-history":[{"count":1,"href":"https:\/\/swling.com\/blog\/wp-json\/wp\/v2\/posts\/60019\/revisions"}],"predecessor-version":[{"id":60022,"href":"https:\/\/swling.com\/blog\/wp-json\/wp\/v2\/posts\/60019\/revisions\/60022"}],"wp:attachment":[{"href":"https:\/\/swling.com\/blog\/wp-json\/wp\/v2\/media?parent=60019"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/swling.com\/blog\/wp-json\/wp\/v2\/categories?post=60019"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/swling.com\/blog\/wp-json\/wp\/v2\/tags?post=60019"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}