{"id":12232,"date":"2015-02-07T15:06:20","date_gmt":"2015-02-07T19:06:20","guid":{"rendered":"http:\/\/swling.com\/blog\/?p=12232"},"modified":"2015-02-07T15:13:01","modified_gmt":"2015-02-07T19:13:01","slug":"pulling-radio-santa-cruz-out-of-the-interference","status":"publish","type":"post","link":"https:\/\/swling.com\/blog\/2015\/02\/pulling-radio-santa-cruz-out-of-the-interference\/","title":{"rendered":"Pulling Radio Santa Cruz out of the interference"},"content":{"rendered":"<p><a href=\"http:\/\/swling.com\/blog\/wp-content\/uploads\/2014\/08\/Bolivia.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-large wp-image-10429\" src=\"http:\/\/swling.com\/blog\/wp-content\/uploads\/2014\/08\/Bolivia-1024x549.jpg\" alt=\"Bolivia\" width=\"640\" height=\"343\" srcset=\"https:\/\/swling.com\/blog\/wp-content\/uploads\/2014\/08\/Bolivia-1024x549.jpg 1024w, https:\/\/swling.com\/blog\/wp-content\/uploads\/2014\/08\/Bolivia-300x161.jpg 300w, https:\/\/swling.com\/blog\/wp-content\/uploads\/2014\/08\/Bolivia-100x53.jpg 100w, https:\/\/swling.com\/blog\/wp-content\/uploads\/2014\/08\/Bolivia.jpg 1149w\" sizes=\"auto, (max-width: 640px) 100vw, 640px\" \/><\/a>I recorded <em>Radio Santa Cruz<\/em> early this morning around 05:00\u00a0UTC on 6,135\u00a0kHz using\u00a0the <a href=\"http:\/\/swling.com\/blog\/tag\/TitanSDR\" target=\"_blank\">TitanSDR<\/a> I currently have under review.<\/p>\n<p><em>Radio Santa Cruz<\/em>\u2018s 10 kW signal from Santa Cruz, Bolivia, was very much audible here in North America, though RSC was\u00a0competing\u00a0with another station on-frequency at the time. Actually, Radio Santa Cruz was broadcasting <em>slightly<\/em> off-frequency&#8211;6134.8 kHz instead of 6,135 kHz. In this case, the fact that RSC was slightly below\u00a0frequency helped me delineate the station&#8217;s audio from that of a competing station.<\/p>\n<p><a href=\"http:\/\/swling.com\/blog\/wp-content\/uploads\/2015\/02\/Fullscreen-capture-272015-54241-PM.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-12234\" src=\"http:\/\/swling.com\/blog\/wp-content\/uploads\/2015\/02\/Fullscreen-capture-272015-54241-PM.jpg\" alt=\"Fullscreen capture 272015 54241 PM\" width=\"848\" height=\"679\" srcset=\"https:\/\/swling.com\/blog\/wp-content\/uploads\/2015\/02\/Fullscreen-capture-272015-54241-PM.jpg 848w, https:\/\/swling.com\/blog\/wp-content\/uploads\/2015\/02\/Fullscreen-capture-272015-54241-PM-300x240.jpg 300w\" sizes=\"auto, (max-width: 848px) 100vw, 848px\" \/><\/a><\/p>\n<p>In the screen-grab of the narrowband channel from the Titan SDR (above&#8211;click to enlarge)\u00a0you can see two distinct carriers spaced only .2 kHz apart (represented by the two peaks in the spectrum display and two parallel vertical lines in the waterfall display).<\/p>\n<p>Here is what the audio sounds like in normal AM mode when we center on the Radio Santa Cruz frequency of 6,134.8 kHz:<\/p>\n<p><iframe loading=\"lazy\" src=\"https:\/\/archive.org\/embed\/201502071730121735176134800\" width=\"500\" height=\"30\" frameborder=\"0\" allowfullscreen=\"allowfullscreen\"><\/iframe><\/p>\n<p>You hear a hetrodyne and garbled noise from a competing station. Not pleasant audio.<\/p>\n<p>If we change from the AM mode to eLSB mode (essentially, the TitanSDR&#8217;s version of synchronous detection on the lower sideband) we are ignoring all of the noise in the upper sideband, allowing the desired signal of RSC to pop out.<\/p>\n<p><a href=\"http:\/\/swling.com\/blog\/wp-content\/uploads\/2015\/02\/Fullscreen-capture-272015-54317-PM.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-12233\" src=\"http:\/\/swling.com\/blog\/wp-content\/uploads\/2015\/02\/Fullscreen-capture-272015-54317-PM.jpg\" alt=\"Fullscreen capture 272015 54317 PM\" width=\"847\" height=\"707\" srcset=\"https:\/\/swling.com\/blog\/wp-content\/uploads\/2015\/02\/Fullscreen-capture-272015-54317-PM.jpg 847w, https:\/\/swling.com\/blog\/wp-content\/uploads\/2015\/02\/Fullscreen-capture-272015-54317-PM-300x250.jpg 300w\" sizes=\"auto, (max-width: 847px) 100vw, 847px\" \/><\/a><\/p>\n<p>You can see in the screen-grab above that now only the lower sideband of the RSC signal is highlighted.\u00a0<a href=\"https:\/\/archive.org\/download\/RadioSantaCruz201502071233491\/RadioSantaCruz-2015-02-07_12'33'49_1.mp3\" target=\"_blank\">Here&#8217;s a 21 minute recording<\/a>:<\/p>\n<p><iframe loading=\"lazy\" src=\"https:\/\/archive.org\/embed\/RadioSantaCruz201502071233491\" width=\"500\" height=\"30\" frameborder=\"0\" allowfullscreen=\"allowfullscreen\"><\/iframe><\/p>\n<p>Makes quite a difference!<\/p>\n<p>It&#8217;s easy to see competing signals and interference on an SDR&#8217;s spectrum display, but if you hear something similar on your portable, try the techniques above to see if it clears up the signal.<\/p>\n<p>If your receiver lacks a selectable synchronous detector, much of the same results can be gained by zero-beating (tuning in) the desired signal in lower sideband mode. Of course, if you have a receiver that lacks SSB mode, the best you can do is tune slightly below frequency in AM, in which case the results will not be as dramatic.<\/p>\n<p>Conclusion? Listening in single-sideband or with a selectable sync detector might be all you need to dig a signal out of the interference.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>I recorded Radio Santa Cruz early this morning around 05:00\u00a0UTC on 6,135\u00a0kHz using\u00a0the TitanSDR I currently have under review. Radio Santa Cruz\u2018s 10 kW signal from Santa Cruz, Bolivia, was very much audible here in North America, though RSC was\u00a0competing\u00a0with another station on-frequency at the time. Actually, Radio Santa Cruz was broadcasting slightly off-frequency&#8211;6134.8 kHz [&hellip;]<\/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":[627,26,43,158,1167],"tags":[2254,3604,3605,3151,4106,3606,3586,2253],"class_list":["post-12232","post","type-post","status-publish","format-standard","hentry","category-how-to","category-radios","category-shortwave-radio","category-software-defined-radio","category-whats-on-shortwave","tag-am-synchronous-detector","tag-elsb","tag-how-to-use-synchronous-detection","tag-radio-santa-cruz","tag-recordings","tag-sync","tag-titansdr","tag-using-a-synchronous-detector"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"","jetpack_shortlink":"https:\/\/wp.me\/pn3uc-3bi","jetpack-related-posts":[{"id":10425,"url":"https:\/\/swling.com\/blog\/2014\/08\/shortwave-radio-recordings-radio-santa-cruz\/","url_meta":{"origin":12232,"position":0},"title":"Shortwave Radio Recordings: Radio Santa Cruz","author":"Thomas","date":"August 2, 2014","format":false,"excerpt":"For your listening pleasure: twenty minutes of Radio Santa Cruz. I recorded Radio Santa Cruz early this morning around 10:00\u00a0UTC on 6,135\u00a0kHz using my WinRadio Excalibur. As you\u2019ll hear in the recording, Radio Santa Cruz's 10 kW signal from Santa Cruz, Bolivia, was very much audible here in North America--even\u2026","rel":"","context":"In &quot;Broadcasters&quot;","block_context":{"text":"Broadcasters","link":"https:\/\/swling.com\/blog\/category\/broadcasters\/"},"img":{"alt_text":"Bolivia","src":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2014\/08\/Bolivia-1024x549.jpg?resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2014\/08\/Bolivia-1024x549.jpg?resize=350%2C200 1x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2014\/08\/Bolivia-1024x549.jpg?resize=525%2C300 1.5x"},"classes":[]},{"id":12172,"url":"https:\/\/swling.com\/blog\/2015\/02\/shortwave-radio-recordings-detecting-radio-guyanavoice-of-guyana\/","url_meta":{"origin":12232,"position":1},"title":"Shortwave Radio Recordings: Detecting Radio Guyana\/Voice of Guyana","author":"Thomas","date":"February 4, 2015","format":false,"excerpt":"Yesterday I learned that\u00a0Voice of Guyana (a.k.a. Radio\u00a0Guyana) is back on the shortwaves after being off-air for many years. Evidently,\u00a0the station repaired some of its transmitters and antennas with the assistance\u00a0of station supporter and technician Jamie Labadia. At this point the station is only capable of a 1,000 watt AM\u2026","rel":"","context":"In &quot;New Products&quot;","block_context":{"text":"New Products","link":"https:\/\/swling.com\/blog\/category\/new-products\/"},"img":{"alt_text":"GuyanaMap-SAM","src":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2015\/02\/GuyanaMap-SAM-1024x418.jpg?resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2015\/02\/GuyanaMap-SAM-1024x418.jpg?resize=350%2C200 1x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2015\/02\/GuyanaMap-SAM-1024x418.jpg?resize=525%2C300 1.5x"},"classes":[]},{"id":7626,"url":"https:\/\/swling.com\/blog\/2013\/10\/am-sync-lessens-noise-in-this-the-voice-of-greece-broadcast\/","url_meta":{"origin":12232,"position":2},"title":"AM sync lessens noise in this The Voice of Greece broadcast","author":"Thomas","date":"October 18, 2013","format":false,"excerpt":"Sometimes, the Voice of Greece plays very little Greek music; October 10th was one of those occasions. \u00a0Nonetheless, I recorded that evening's broadcast. Using AM sync for sideband noise In the first hour of the 10\/10 VOG broadcast, you'll hear a pulsating noise from an unknown origin (possibly a jammer?).\u2026","rel":"","context":"In &quot;AM&quot;","block_context":{"text":"AM","link":"https:\/\/swling.com\/blog\/category\/am\/"},"img":{"alt_text":"TheParthenonAthens","src":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2013\/01\/TheParthenonAthens-300x210.jpg?resize=350%2C200","width":350,"height":200},"classes":[]},{"id":14543,"url":"https:\/\/swling.com\/blog\/2015\/09\/using-synchronous-detection-and-notch-filter-to-eliminate-het-noise\/","url_meta":{"origin":12232,"position":3},"title":"Using synchronous detection and notch filter to eliminate het noise","author":"Thomas","date":"September 1, 2015","format":false,"excerpt":"A few days ago, I tuned to 9,420 kHz and found a relatively strong signal from the Avlis transmitter site of the Voice of Greece. The broadcast was quite clear until a heterodyne (het) tone popped up out of nowhere. I checked the spectrum display of my Excalibur to find\u2026","rel":"","context":"In &quot;AM&quot;","block_context":{"text":"AM","link":"https:\/\/swling.com\/blog\/category\/am\/"},"img":{"alt_text":"WinRadioExcalibur-VOG-Notch","src":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2015\/09\/WinRadioExcalibur-VOG-Notch-1024x443.jpg?resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2015\/09\/WinRadioExcalibur-VOG-Notch-1024x443.jpg?resize=350%2C200 1x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2015\/09\/WinRadioExcalibur-VOG-Notch-1024x443.jpg?resize=525%2C300 1.5x"},"classes":[]},{"id":9777,"url":"https:\/\/swling.com\/blog\/2014\/05\/pirate-radio-recordings-hot-legs-radio\/","url_meta":{"origin":12232,"position":4},"title":"Pirate Radio Recordings: Hot Legs Radio (corrected)","author":"Thomas","date":"May 29, 2014","format":false,"excerpt":"For your listening pleasure: about 20 minutes\u00a0of pirate radio station,\u00a0Hot Legs\u00a0Radio\u2013recorded May 25, 2014 starting around 1:55\u00a0UTC. Hot Legs Radio\u00a0was broadcasting around 6,925\u00a0kHz in AM. Hot Legs\u00a0was rather weak and somewhat over-modulated during this broadcast. Indeed, in regular AM mode, I couldn't make out the station ID at all. Fortunately,\u2026","rel":"","context":"In &quot;Music&quot;","block_context":{"text":"Music","link":"https:\/\/swling.com\/blog\/category\/music\/"},"img":{"alt_text":"\"Grandma! Is that Cyndi Lauper buried in the static?\"","src":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2011\/07\/RadioListening.jpg?resize=350%2C200","width":350,"height":200},"classes":[]},{"id":12313,"url":"https:\/\/swling.com\/blog\/2015\/02\/reader-survey-comparing-the-tecsun-pl-680-and-pl-660-synchronous-detection\/","url_meta":{"origin":12232,"position":5},"title":"Reader Survey: Comparing the Tecsun PL-680 and PL-660 synchronous detection","author":"Thomas","date":"February 16, 2015","format":false,"excerpt":"[Update: Please note that this survey has been closed, but the audio samples--labeled Radio A and Radio B--will remain to allow others the opportunity to make an evaluation prior to reading the PL-680 review.] [Update 2: The PL-680 review and readers' survey results have now been posted! Check it out\u2026","rel":"","context":"In &quot;New Products&quot;","block_context":{"text":"New Products","link":"https:\/\/swling.com\/blog\/category\/new-products\/"},"img":{"alt_text":"PL-680-Sync-Detector","src":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2015\/02\/PL-680-Sync-Detector.jpg?resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2015\/02\/PL-680-Sync-Detector.jpg?resize=350%2C200 1x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2015\/02\/PL-680-Sync-Detector.jpg?resize=525%2C300 1.5x"},"classes":[]}],"jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/swling.com\/blog\/wp-json\/wp\/v2\/posts\/12232","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=12232"}],"version-history":[{"count":0,"href":"https:\/\/swling.com\/blog\/wp-json\/wp\/v2\/posts\/12232\/revisions"}],"wp:attachment":[{"href":"https:\/\/swling.com\/blog\/wp-json\/wp\/v2\/media?parent=12232"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/swling.com\/blog\/wp-json\/wp\/v2\/categories?post=12232"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/swling.com\/blog\/wp-json\/wp\/v2\/tags?post=12232"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}