{"id":60359,"date":"2024-08-07T06:23:37","date_gmt":"2024-08-07T10:23:37","guid":{"rendered":"https:\/\/swling.com\/blog\/?p=60359"},"modified":"2024-08-07T06:23:37","modified_gmt":"2024-08-07T10:23:37","slug":"can-you-help-dan-solve-this-50-year-old-radio-mystery","status":"publish","type":"post","link":"https:\/\/swling.com\/blog\/2024\/08\/can-you-help-dan-solve-this-50-year-old-radio-mystery\/","title":{"rendered":"Can you help Dan solve this 50 year old radio mystery?"},"content":{"rendered":"

\"Photo<\/a>Many thanks to SWLing Post and\u00a0Shortwave Radio Audio Archive<\/a> contributor, Dan Greenall, who writes:<\/strong><\/p>\n

Hi Thomas<\/p>\n

From the early 1970’s, where sadly, some of my original logbooks went missing many years ago.<\/p>\n

ANTEL, the Administracion Nacional de Telecommunicaciones in Montevideo, Uruguay used to use its telephone time announcement instead of a voice mirror – so they got their name ‘La Senal’ in the 1970’s. Their voice announcements in SSB mode were in Spanish and the station could be found on frequencies all over the shortwave spectrum, including 5772 kHz (CXL20), 8037 kHz (CXL21), 10770 kHz (CXL24), 11660 kHz (CXL25), 14575 kHz (CXL26), 16047.5 kHz (CXL28), and 19525 kHz (CXL33). The accompanying recording was made on January 9, 1971 on about 13550 kHz.<\/p>\n

La Senal Uruguay Jan 9 1971 13.55:<\/strong><\/p>\nhttps:\/\/archive.org\/download\/la-senal-uruguay-jan-9-1971-13.55\/La%20Senal%20Uruguay%20Jan%209%201971%2013.55.m4a<\/a><\/audio>\n

In those days, it paid to belong to a good DX club (such as SPEEDX) or I may not have been able to identify this station at all. I was also able to get my hands on a used copy of the Klingenfuss guide to utility stations which had very detailed frequency and callsign information. Unfortunately, I let this valuable resource go a number of years ago.<\/p>\n

And now for the mystery……<\/h2>\n

Around the same time (early 1970’s), I heard and recorded this similar styled transmission, except it was in the French language, and which remains unidentified to this day. I have no exact date\/time heard or frequency information for this one.<\/p>\n

All recordings made in Ancaster, Ontario, Canada. (40 miles SW of Toronto)<\/p>\n

Mystery French Time Station:<\/strong><\/p>\nhttps:\/\/archive.org\/download\/la-senal-uruguay-jan-9-1971-13.55\/French%20Time%20Station%201971.m4a<\/a><\/audio>\n

Any guesses will be greatly appreciated.<\/p>\n

73<\/p>\n

Dan Greenall<\/p>\n

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

Many thanks to SWLing Post and\u00a0Shortwave Radio Audio Archive contributor, Dan Greenall, who writes: Hi Thomas From the early 1970’s, where sadly, some of my original logbooks went missing many years ago. ANTEL, the Administracion Nacional de Telecommunicaciones in Montevideo, Uruguay used to use its telephone time announcement instead of a voice mirror – so […]<\/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":[10271,5448,4106,10455],"class_list":["post-60359","post","type-post","status-publish","format-standard","hentry","category-news","category-nostalgia","category-recordings","category-shortwave-radio","tag-dan-greenall","tag-mystery-signals","tag-recordings","tag-voice-mirrors"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"","jetpack_shortlink":"https:\/\/wp.me\/pn3uc-fHx","jetpack-related-posts":[{"id":65072,"url":"https:\/\/swling.com\/blog\/2026\/01\/taiwan-on-shortwave-then-and-now\/","url_meta":{"origin":60359,"position":0},"title":"Taiwan on Shortwave \u2013 Then and Now","author":"Thomas","date":"January 2, 2026","format":false,"excerpt":"by Dan Greenall For nearly a half-century, The Voice of Free China broadcast programs via shortwave to a worldwide audience from Taipei, Taiwan. As a relatively new SWL in the early 1970\u2019s, I was always excited to hear English language programs from that part of the world, far away from\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\/01\/Voice-of-Free-China-QSL.jpeg?resize=350%2C200&ssl=1","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2026\/01\/Voice-of-Free-China-QSL.jpeg?resize=350%2C200&ssl=1 1x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2026\/01\/Voice-of-Free-China-QSL.jpeg?resize=525%2C300&ssl=1 1.5x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2026\/01\/Voice-of-Free-China-QSL.jpeg?resize=700%2C400&ssl=1 2x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2026\/01\/Voice-of-Free-China-QSL.jpeg?resize=1050%2C600&ssl=1 3x"},"classes":[]},{"id":63399,"url":"https:\/\/swling.com\/blog\/2025\/07\/the-voice-of-mongolia-then-and-now\/","url_meta":{"origin":60359,"position":1},"title":"The Voice of Mongolia – Then and Now","author":"Thomas","date":"July 17, 2025","format":false,"excerpt":"Many thanks to SWLing Post contributor Dan Greenall, who writes: The Voice of Mongolia from Ulaanbaatar was always tough to hear from my location in southern Ontario, Canada. Relatively quiet conditions and a clear frequency eventually allowed me to make a recording of their interval signal and bilingual identification (presumed\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\/2021\/08\/voice-of-Mongolia-Transmitter-Site-Mark-Fahey-1.jpeg?resize=350%2C200&ssl=1","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2021\/08\/voice-of-Mongolia-Transmitter-Site-Mark-Fahey-1.jpeg?resize=350%2C200&ssl=1 1x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2021\/08\/voice-of-Mongolia-Transmitter-Site-Mark-Fahey-1.jpeg?resize=525%2C300&ssl=1 1.5x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2021\/08\/voice-of-Mongolia-Transmitter-Site-Mark-Fahey-1.jpeg?resize=700%2C400&ssl=1 2x"},"classes":[]},{"id":63733,"url":"https:\/\/swling.com\/blog\/2025\/08\/mexico-on-shortwave-then-and-now\/","url_meta":{"origin":60359,"position":2},"title":"Mexico on Shortwave \u2013 Then and Now","author":"Thomas","date":"August 22, 2025","format":false,"excerpt":"by Dan Greenall Back in the early 1970\u2019s, a wide variety of Mexican stations could be heard on shortwave as evidenced by the loggings columns in the SPEEDX club\u2019s monthly bulletins. Examples from this time period can be found here: https:\/\/www.worldradiohistory.com\/Speedx.htm As well, the late Dr. Richard E. Wood wrote\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\/2025\/08\/Radio-Educacion-1994-front.jpeg?resize=350%2C200&ssl=1","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2025\/08\/Radio-Educacion-1994-front.jpeg?resize=350%2C200&ssl=1 1x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2025\/08\/Radio-Educacion-1994-front.jpeg?resize=525%2C300&ssl=1 1.5x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2025\/08\/Radio-Educacion-1994-front.jpeg?resize=700%2C400&ssl=1 2x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2025\/08\/Radio-Educacion-1994-front.jpeg?resize=1050%2C600&ssl=1 3x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2025\/08\/Radio-Educacion-1994-front.jpeg?resize=1400%2C800&ssl=1 4x"},"classes":[]},{"id":64341,"url":"https:\/\/swling.com\/blog\/2025\/10\/algeria-on-shortwave-then-and-now\/","url_meta":{"origin":60359,"position":3},"title":"Algeria on Shortwave – Then and Now","author":"Thomas","date":"October 24, 2025","format":false,"excerpt":"Many thanks to SWLing Post contributor Dan Greenall, for sharing the following guest post: Algeria on Shortwave - Then and Now by Dan Greenall In the early 1970s, Radiodiffusion-Television Algerienne ran a modest shortwave service (no English) mainly for North Africa, the Middle East,\u00a0and Europe. A copy of their schedule\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\/2025\/10\/Greenall-Algeria-1.jpeg?resize=350%2C200&ssl=1","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2025\/10\/Greenall-Algeria-1.jpeg?resize=350%2C200&ssl=1 1x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2025\/10\/Greenall-Algeria-1.jpeg?resize=525%2C300&ssl=1 1.5x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2025\/10\/Greenall-Algeria-1.jpeg?resize=700%2C400&ssl=1 2x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2025\/10\/Greenall-Algeria-1.jpeg?resize=1050%2C600&ssl=1 3x"},"classes":[]},{"id":60985,"url":"https:\/\/swling.com\/blog\/2024\/10\/short-recording-from-the-voice-of-indonesia\/","url_meta":{"origin":60359,"position":4},"title":"Short recording from the Voice of Indonesia","author":"Thomas","date":"October 28, 2024","format":false,"excerpt":"Many thanks to SWLing Post contributor, Dan Greenall, who writes: This is a follow up to the SWLing Post article from last May informing about a frequency change at the Voice of Indonesia from 4750 to 4755 kHz. 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