{"id":30450,"date":"2018-01-24T17:46:16","date_gmt":"2018-01-24T21:46:16","guid":{"rendered":"https:\/\/swling.com\/blog\/?p=30450"},"modified":"2018-01-26T13:40:08","modified_gmt":"2018-01-26T17:40:08","slug":"digging-in-the-noise-weak-signal-audio-recovery-with-the-airspy-hf-and-elad-fdm-s2","status":"publish","type":"post","link":"https:\/\/swling.com\/blog\/2018\/01\/digging-in-the-noise-weak-signal-audio-recovery-with-the-airspy-hf-and-elad-fdm-s2\/","title":{"rendered":"Digging in the Noise: Weak Signal Audio Recovery with the AirSpy HF+ and Elad FDM-S2"},"content":{"rendered":"<p>I&#8217;m currently spending the better part of a week at <strong><a href=\"http:\/\/oregonstateparks.org\/index.cfm?do=parkPage.dsp_parkPage&amp;parkId=134\">Cape Lookout State Park<\/a><\/strong> on the Oregon coast, with a great view of the ocean through tall evergreen trees. This is one of my favorite parks in the Pacific Northwest, especially when DXing during the blustery winters from one of the nice cabins at Cape Lookout.<\/p>\n<p><em>The view from the beach near my cabin; the turbulent waves were a precursor to the gale force winds at the park during the night of the 23rd!<\/em><\/p>\n<p><span class=\"embed-youtube\" style=\"text-align:center; display: block;\"><iframe loading=\"lazy\" class=\"youtube-player\" width=\"625\" height=\"352\" src=\"https:\/\/www.youtube.com\/embed\/EYUSU_gzgu4?version=3&#038;rel=1&#038;showsearch=0&#038;showinfo=1&#038;iv_load_policy=1&#038;fs=1&#038;hl=en-US&#038;autohide=2&#038;wmode=transparent\" allowfullscreen=\"true\" style=\"border:0;\" sandbox=\"allow-scripts allow-same-origin allow-popups allow-presentation allow-popups-to-escape-sandbox\"><\/iframe><\/span><\/p>\n<p>Although I&#8217;m at the park for trans-Pacific medium wave DXing, I&#8217;m also comparing receivers, both SDRs and portables. This morning I sought out a few weak shortwave signals, pitting the <strong><a href=\"http:\/\/shop.elad-usa.com\/sdr-radio\/fdm-s2\/\">Elad FDM-S2<\/a><\/strong> SDR ($529 USD) against the <strong><a href=\"https:\/\/airspy.com\/airspy-hf-plus\/\">AirSpy HF+<\/a><\/strong> ($199 USD). I have a pair of the HF+ receivers to cover all of medium wave (as the FDM-S2 easily does). Many <em>SWLing Post<\/em> readers already know that the upstart HF+ trades bandwidth to gain high performance in order to keep the price reasonable.<\/p>\n<p>My antenna used for the following recordings was a small &#8220;Flag&#8221; antenna using a <strong><a href=\"https:\/\/www.wellbrook.uk.com\/loopantennas\/FLG100LN\">Wellbrook Communications FLG100LN<\/a><\/strong> module and a 2K ohm variable potentiometer for termination. The design uses crossed tent poles in an &#8220;X&#8221; formation to support the wire loop. This design travels easily in a compact package; I have Dave Aichelman of Grants Pass, Oregon to thank for this very useful &#8220;tent pole loop&#8221; implementation of the Wellbrook FLG100LN.<\/p>\n<p>The Wellbrook-based antenna functions superbly, and its low-noise design helps hold down QRM from the nearby cabins (which unfortunately have been &#8220;upgraded&#8221; recently with noisy cold fluorescent [CFL] light bulbs). The area around the Cape Lookout cabins used to be superbly low noise and suitable for radio listening, but now it is more of a challenge than before. The Wellbrook FLG100LN is perfect for the situation though; Wellbrook <strong><a href=\"https:\/\/www.wellbrook.uk.com\/loopantennas\/Loop_Antennas\/ALA1530LNP\">ALA1530LN\u00a0 Pro<\/a><\/strong> and <strong><a href=\"https:\/\/www.wellbrook.uk.com\/loopantennas\/Loop_Antennas\/ALA1530SP\">ALA1530S+<\/a><\/strong> 1-meter loop antennas work commendably at the park too.<\/p>\n<p><em>The Wellbrook FLG100LN module with a home brew RFI choke in-line<\/em><\/p>\n<p><a href=\"https:\/\/swling.com\/blog\/wp-content\/uploads\/2018\/12\/FLG100LNmodule.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-large wp-image-30476\" src=\"https:\/\/swling.com\/blog\/wp-content\/uploads\/2018\/12\/FLG100LNmodule-1024x485.jpg\" alt=\"\" width=\"625\" height=\"296\" srcset=\"https:\/\/swling.com\/blog\/wp-content\/uploads\/2018\/12\/FLG100LNmodule-1024x485.jpg 1024w, https:\/\/swling.com\/blog\/wp-content\/uploads\/2018\/12\/FLG100LNmodule-300x142.jpg 300w, https:\/\/swling.com\/blog\/wp-content\/uploads\/2018\/12\/FLG100LNmodule-768x364.jpg 768w, https:\/\/swling.com\/blog\/wp-content\/uploads\/2018\/12\/FLG100LNmodule-624x295.jpg 624w, https:\/\/swling.com\/blog\/wp-content\/uploads\/2018\/12\/FLG100LNmodule.jpg 1200w\" sizes=\"auto, (max-width: 625px) 100vw, 625px\" \/><\/a><\/p>\n<p><em>A 2K ohm variable potentiometer is protected from the elements in a small plastic bag. The &#8220;pot&#8221; is adjusted for the best nulling of medium wave stations off the back side of the antenna&#8217;s reception pattern.<\/em><\/p>\n<p><a href=\"https:\/\/swling.com\/blog\/wp-content\/uploads\/2018\/12\/TPloop_term.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-large wp-image-30473\" src=\"https:\/\/swling.com\/blog\/wp-content\/uploads\/2018\/12\/TPloop_term-1024x568.jpg\" alt=\"\" width=\"625\" height=\"347\" srcset=\"https:\/\/swling.com\/blog\/wp-content\/uploads\/2018\/12\/TPloop_term-1024x568.jpg 1024w, https:\/\/swling.com\/blog\/wp-content\/uploads\/2018\/12\/TPloop_term-300x167.jpg 300w, https:\/\/swling.com\/blog\/wp-content\/uploads\/2018\/12\/TPloop_term-768x426.jpg 768w, https:\/\/swling.com\/blog\/wp-content\/uploads\/2018\/12\/TPloop_term-624x346.jpg 624w, https:\/\/swling.com\/blog\/wp-content\/uploads\/2018\/12\/TPloop_term.jpg 1200w\" sizes=\"auto, (max-width: 625px) 100vw, 625px\" \/><\/a><\/p>\n<p><em>The &#8220;tent pole loop&#8221; antenna is strapped to a fence railing with ultra-strong Gorilla Tape to keep the 7-ft. square loop vertical.<\/em><\/p>\n<p><a href=\"https:\/\/swling.com\/blog\/wp-content\/uploads\/2018\/12\/tentpoleloop.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-large wp-image-30475\" src=\"https:\/\/swling.com\/blog\/wp-content\/uploads\/2018\/12\/tentpoleloop-1024x729.jpg\" alt=\"\" width=\"625\" height=\"445\" srcset=\"https:\/\/swling.com\/blog\/wp-content\/uploads\/2018\/12\/tentpoleloop-1024x729.jpg 1024w, https:\/\/swling.com\/blog\/wp-content\/uploads\/2018\/12\/tentpoleloop-300x214.jpg 300w, https:\/\/swling.com\/blog\/wp-content\/uploads\/2018\/12\/tentpoleloop-768x547.jpg 768w, https:\/\/swling.com\/blog\/wp-content\/uploads\/2018\/12\/tentpoleloop-624x444.jpg 624w, https:\/\/swling.com\/blog\/wp-content\/uploads\/2018\/12\/tentpoleloop.jpg 1200w\" sizes=\"auto, (max-width: 625px) 100vw, 625px\" \/><\/a><\/p>\n<p><strong>On with the recordings&#8230;<\/strong><\/p>\n<p>For the FDM-S2 and HF+ comparisons I used the <strong><a href=\"http:\/\/www.sdr-radio.com\/Software\/Version3\">SDR-Console V3<\/a><\/strong> software. Every parameter was identical for the receivers&#8211;sampling bandwidth, filter bandwidth, AGC, mode and so on.<\/p>\n<p><strong>Take a critical listen to the weak signals recorded with the SDR receivers, identified as only &#8220;Radio A&#8221; and &#8220;Radio B&#8221;.<\/strong> <span style=\"color: #ff0000\"><strong>A link to a poll is at the end of this article;<\/strong><\/span> <strong>please indicate which recording of each pair has the most intelligible audio in your opinion, and submit your choices when you&#8217;ve made up your mind on each audio clip.<\/strong> After a week or so I&#8217;ll post the results of the voting, and identify the receivers.<\/p>\n<p><strong>9.615 MHz, LSB,\u00a0<\/strong>Radio A<\/p>\n<audio class=\"wp-audio-shortcode\" id=\"audio-30450-1\" preload=\"none\" style=\"width: 100%;\" controls=\"controls\"><source type=\"audio\/mpeg\" src=\"https:\/\/swling.com\/blog\/wp-content\/uploads\/2018\/01\/24-Jan-2018-10h13m51s-9.615-MHz-LSB-1.mp3?_=1\" \/><a href=\"https:\/\/swling.com\/blog\/wp-content\/uploads\/2018\/01\/24-Jan-2018-10h13m51s-9.615-MHz-LSB-1.mp3\">https:\/\/swling.com\/blog\/wp-content\/uploads\/2018\/01\/24-Jan-2018-10h13m51s-9.615-MHz-LSB-1.mp3<\/a><\/audio>\n<p><strong><br \/>\n9.615 MHz, LSB,\u00a0<\/strong>Radio B (note: the same male announcer heard in clip &#8220;A&#8221; begins at 00:14 in this &#8220;B&#8221; clip)<\/p>\n<audio class=\"wp-audio-shortcode\" id=\"audio-30450-2\" preload=\"none\" style=\"width: 100%;\" controls=\"controls\"><source type=\"audio\/mpeg\" src=\"https:\/\/swling.com\/blog\/wp-content\/uploads\/2018\/01\/24-Jan-2018-10h14m41s-9.615-MHz-LSB.mp3?_=2\" \/><a href=\"https:\/\/swling.com\/blog\/wp-content\/uploads\/2018\/01\/24-Jan-2018-10h14m41s-9.615-MHz-LSB.mp3\">https:\/\/swling.com\/blog\/wp-content\/uploads\/2018\/01\/24-Jan-2018-10h14m41s-9.615-MHz-LSB.mp3<\/a><\/audio>\n<p>&nbsp;<\/p>\n<p><strong>9.730 MHz, USB,\u00a0<\/strong>Radio A<\/p>\n<audio class=\"wp-audio-shortcode\" id=\"audio-30450-3\" preload=\"none\" style=\"width: 100%;\" controls=\"controls\"><source type=\"audio\/mpeg\" src=\"https:\/\/swling.com\/blog\/wp-content\/uploads\/2018\/01\/24-Jan-2018-12h20m41s-9.73-MHz-USB.mp3?_=3\" \/><a href=\"https:\/\/swling.com\/blog\/wp-content\/uploads\/2018\/01\/24-Jan-2018-12h20m41s-9.73-MHz-USB.mp3\">https:\/\/swling.com\/blog\/wp-content\/uploads\/2018\/01\/24-Jan-2018-12h20m41s-9.73-MHz-USB.mp3<\/a><\/audio>\n<p><strong><br \/>\n9.730 MHz, USB,\u00a0<\/strong>Radio B<\/p>\n<audio class=\"wp-audio-shortcode\" id=\"audio-30450-4\" preload=\"none\" style=\"width: 100%;\" controls=\"controls\"><source type=\"audio\/mpeg\" src=\"https:\/\/swling.com\/blog\/wp-content\/uploads\/2018\/01\/24-Jan-2018-12h21m11s-9.73-MHz-USB.mp3?_=4\" \/><a href=\"https:\/\/swling.com\/blog\/wp-content\/uploads\/2018\/01\/24-Jan-2018-12h21m11s-9.73-MHz-USB.mp3\">https:\/\/swling.com\/blog\/wp-content\/uploads\/2018\/01\/24-Jan-2018-12h21m11s-9.73-MHz-USB.mp3<\/a><\/audio>\n<p>&nbsp;<\/p>\n<p><strong>7.230 MHz, S-AM,\u00a0<\/strong>Radio A<\/p>\n<audio class=\"wp-audio-shortcode\" id=\"audio-30450-5\" preload=\"none\" style=\"width: 100%;\" controls=\"controls\"><source type=\"audio\/mpeg\" src=\"https:\/\/swling.com\/blog\/wp-content\/uploads\/2018\/01\/24-Jan-2018-12h44m36s-7.23-MHz-SAM.mp3?_=5\" \/><a href=\"https:\/\/swling.com\/blog\/wp-content\/uploads\/2018\/01\/24-Jan-2018-12h44m36s-7.23-MHz-SAM.mp3\">https:\/\/swling.com\/blog\/wp-content\/uploads\/2018\/01\/24-Jan-2018-12h44m36s-7.23-MHz-SAM.mp3<\/a><\/audio>\n<p><strong><br \/>\n7.230 MHz, S-AM,\u00a0<\/strong>Radio B<\/p>\n<audio class=\"wp-audio-shortcode\" id=\"audio-30450-6\" preload=\"none\" style=\"width: 100%;\" controls=\"controls\"><source type=\"audio\/mpeg\" src=\"https:\/\/swling.com\/blog\/wp-content\/uploads\/2018\/01\/24-Jan-2018-12h45m20s-7.23-MHz-SAM.mp3?_=6\" \/><a href=\"https:\/\/swling.com\/blog\/wp-content\/uploads\/2018\/01\/24-Jan-2018-12h45m20s-7.23-MHz-SAM.mp3\">https:\/\/swling.com\/blog\/wp-content\/uploads\/2018\/01\/24-Jan-2018-12h45m20s-7.23-MHz-SAM.mp3<\/a><\/audio>\n<p>&nbsp;<\/p>\n<p><strong>9.860 MHz, S-AM,\u00a0<\/strong>Radio A<\/p>\n<audio class=\"wp-audio-shortcode\" id=\"audio-30450-7\" preload=\"none\" style=\"width: 100%;\" controls=\"controls\"><source type=\"audio\/mpeg\" src=\"https:\/\/swling.com\/blog\/wp-content\/uploads\/2018\/01\/24-Jan-2018-13h43m28s-9.86-MHz-SAM.mp3?_=7\" \/><a href=\"https:\/\/swling.com\/blog\/wp-content\/uploads\/2018\/01\/24-Jan-2018-13h43m28s-9.86-MHz-SAM.mp3\">https:\/\/swling.com\/blog\/wp-content\/uploads\/2018\/01\/24-Jan-2018-13h43m28s-9.86-MHz-SAM.mp3<\/a><\/audio>\n<p><strong><br \/>\n9.860 MHz, S-AM,\u00a0<\/strong>Radio\u00a0 B<\/p>\n<audio class=\"wp-audio-shortcode\" id=\"audio-30450-8\" preload=\"none\" style=\"width: 100%;\" controls=\"controls\"><source type=\"audio\/mpeg\" src=\"https:\/\/swling.com\/blog\/wp-content\/uploads\/2018\/01\/24-Jan-2018-13h44m02s-9.86-MHz-SAM.mp3?_=8\" \/><a href=\"https:\/\/swling.com\/blog\/wp-content\/uploads\/2018\/01\/24-Jan-2018-13h44m02s-9.86-MHz-SAM.mp3\">https:\/\/swling.com\/blog\/wp-content\/uploads\/2018\/01\/24-Jan-2018-13h44m02s-9.86-MHz-SAM.mp3<\/a><\/audio>\n<p>&nbsp;<\/p>\n<p>Note on 7.230 MHz recording: this was an interesting frequency, as the signal was tightly surrounded by a very strong local 40m ham radio LSB station as well as a strong China Radio International signal. There were other strong amateur and broadcast stations within 30-50 kHz of 7.230 MHz, also. This A-B test more than the others may indicate receiver performance in a strong RF environment on a crowded band.<\/p>\n<p><strong>Ready for the poll?<\/strong> Register your votes at the Google Docs form below:<\/p>\n<p style=\"text-align: center\"><strong><a href=\"https:\/\/tinyurl.com\/ya38wj69\" target=\"_blank\" rel=\"noopener\">https:\/\/tinyurl.com\/ya38wj69<\/a><\/strong><\/p>\n<p>In a week to 10 days I&#8217;ll post the results in another article. <strong>NOTE:<\/strong>\u00a0I haven&#8217;t provided a \u201cboth sound the same\u201d choice in the poll to encourage you to \u2018dig deep\u2019 into the audio and listen critically&#8211;to find something that stands out in one clip versus the other.<\/p>\n<p style=\"text-align: center\"><em>Guy Atkins is a Sr. Graphic Designer for T-Mobile and lives near Seattle, Washington. \u00a0He\u2019s a regular contributor to the SWLing Post.<\/em><\/p>\n","protected":false},"excerpt":{"rendered":"<p>I&#8217;m currently spending the better part of a week at Cape Lookout State Park on the Oregon coast, with a great view of the ocean through tall evergreen trees. This is one of my favorite parks in the Pacific Northwest, especially when DXing during the blustery winters from one of the nice cabins at Cape [&hellip;]<\/p>\n","protected":false},"author":55,"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":false,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"font":"","enabled":false},"version":2}},"categories":[5935,399,26,746,129,43,158],"tags":[3724,6613,6785,6719,2224,968,3010,3393,1254,4106,2049],"class_list":["post-30450","post","type-post","status-publish","format-standard","hentry","category-dx","category-dxpeditions","category-radios","category-recordings","category-reviews","category-shortwave-radio","category-software-defined-radio","tag-airspy","tag-airspy-hf","tag-airspy-hf-v-elad-fdm-s2","tag-comparison","tag-dxpedition","tag-elad","tag-elad-fdm-s2","tag-hf","tag-recording","tag-recordings","tag-review"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"","jetpack_shortlink":"https:\/\/wp.me\/pn3uc-7V8","jetpack-related-posts":[{"id":30705,"url":"https:\/\/swling.com\/blog\/2018\/02\/results-airspy-hf-vs-elad-fdm-s2-weak-signal-comparisions\/","url_meta":{"origin":30450,"position":0},"title":"Results: AirSpy HF+ vs Elad FDM-S2 Weak Signal Comparisions","author":"Guy Atkins","date":"February 3, 2018","format":false,"excerpt":"Looking north toward Cape Lookout, Oregon, near the site of my SDR receiver recordings. Photo courtesy of Wikimedia Commons. In my original article 10 days ago, I set up a SWLing Post reader poll to let you give your opinion on which shortwave recordings within four pairs of audio files\u2026","rel":"","context":"In &quot;DX&quot;","block_context":{"text":"DX","link":"https:\/\/swling.com\/blog\/category\/dx\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2018\/12\/Camp_Meriwether_Cape_Lookout_State_Park.jpg?resize=350%2C200&ssl=1","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2018\/12\/Camp_Meriwether_Cape_Lookout_State_Park.jpg?resize=350%2C200&ssl=1 1x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2018\/12\/Camp_Meriwether_Cape_Lookout_State_Park.jpg?resize=525%2C300&ssl=1 1.5x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2018\/12\/Camp_Meriwether_Cape_Lookout_State_Park.jpg?resize=700%2C400&ssl=1 2x"},"classes":[]},{"id":39304,"url":"https:\/\/swling.com\/blog\/2019\/08\/airspy-hf-discovery-first-impressions-on-medium-wave-vs-elad-fdm-duor\/","url_meta":{"origin":30450,"position":1},"title":"AirSpy HF+ Discovery: First Impressions on Medium Wave vs. Elad FDM-DUOr","author":"Guy Atkins","date":"August 25, 2019","format":false,"excerpt":"The highly anticipated AirSpy HF+ Discovery SDR has been in the hands of early adopters for about two weeks--and I've seen nothing but positive comments! After a long run (2007-2013) with a Microtelecom Perseus, my SDR of choice became the Elad FDM-S2, and more recently an Elad FDM-DUOr \"hybrid\" SDR\u2026","rel":"","context":"In &quot;AM&quot;","block_context":{"text":"AM","link":"https:\/\/swling.com\/blog\/category\/am\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2019\/08\/hfplus_discovery.png?resize=350%2C200&ssl=1","width":350,"height":200},"classes":[]},{"id":29878,"url":"https:\/\/swling.com\/blog\/2017\/12\/brief-medium-wave-tests-of-the-hf-and-fdm-s2-sdrs-in-a-suburban-location\/","url_meta":{"origin":30450,"position":2},"title":"Brief Medium Wave Tests of the HF+ and FDM-S2 SDRs in a Suburban Location","author":"Guy Atkins","date":"December 31, 2017","format":false,"excerpt":"The AirSpy HF+ is the new SDR on the block, but how does it compare to the Elad FDM-S2 which is more than 2-1\/2 times its $199 price? My main interest is finding out how they compare in a very RF-quiet DXpedition setting, but today I compared the two briefly\u2026","rel":"","context":"In &quot;Radios&quot;","block_context":{"text":"Radios","link":"https:\/\/swling.com\/blog\/category\/radios\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2017\/12\/HF_FDM-S2-300x194.jpg?resize=350%2C200&ssl=1","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2017\/12\/HF_FDM-S2-300x194.jpg?resize=350%2C200&ssl=1 1x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2017\/12\/HF_FDM-S2-300x194.jpg?resize=525%2C300&ssl=1 1.5x"},"classes":[]},{"id":41190,"url":"https:\/\/swling.com\/blog\/2019\/12\/mike-compares-the-sdrplay-rspdx-on-mediumwave-and-longwave\/","url_meta":{"origin":30450,"position":3},"title":"Mike compares the SDRplay RSPdx on mediumwave and longwave","author":"Thomas","date":"December 15, 2019","format":false,"excerpt":"Many thanks to SWLing Post contributor, Mike Ladd with\u00a0SDRplay, who shares the following videos comparing the new RSPdx with a number of benchmark SDRs: SDRplay RSPdx and ELAD FDM-S2 weak NDB station https:\/\/youtu.be\/KbHz4sqJmpA SDRplay RSPdx and ELAD FDM-S2 medium wave selectivity https:\/\/youtu.be\/ah5Zu8qgvp8 SDRplay RSPdx and Airspy HF+ Discovery medium wave\u2026","rel":"","context":"In &quot;DX&quot;","block_context":{"text":"DX","link":"https:\/\/swling.com\/blog\/category\/dx\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2019\/11\/SDRplay-RSPdx-1-3.jpg?resize=350%2C200&ssl=1","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2019\/11\/SDRplay-RSPdx-1-3.jpg?resize=350%2C200&ssl=1 1x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2019\/11\/SDRplay-RSPdx-1-3.jpg?resize=525%2C300&ssl=1 1.5x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2019\/11\/SDRplay-RSPdx-1-3.jpg?resize=700%2C400&ssl=1 2x"},"classes":[]},{"id":29951,"url":"https:\/\/swling.com\/blog\/2018\/01\/addendum-more-notes-on-the-hf-sdr-on-medium-wave-long-wave\/","url_meta":{"origin":30450,"position":4},"title":"Addendum: More Notes on the HF+ SDR on Medium Wave &amp; Long Wave","author":"Guy Atkins","date":"January 4, 2018","format":false,"excerpt":"In my recent post on the AirSpy HF+ vs Elad FDM-S2, I commented on medium wave reception only. This past weekend I swapped out the Wellbrook ALA1530S+ for another Wellbrook loop, the ALA1530LN Pro. This LN Pro model is less likely to overload receivers at my suburban Tacoma, WA location.\u2026","rel":"","context":"In &quot;Longwave&quot;","block_context":{"text":"Longwave","link":"https:\/\/swling.com\/blog\/category\/longwave\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2018\/01\/AirSpy_HF-300x202.jpg?resize=350%2C200&ssl=1","width":350,"height":200},"classes":[]},{"id":29434,"url":"https:\/\/swling.com\/blog\/2017\/12\/the-airspy-hf-sdr-first-impressions\/","url_meta":{"origin":30450,"position":5},"title":"The Airspy HF+ SDR: First impressions","author":"Thomas","date":"December 3, 2017","format":false,"excerpt":"Yesterday, I received a package in the mail containing the new Airspy HF+\u00a0software defined radio receiver. It came as a bit of a surprise. I've been busy lately with humanitarian work, the radio spectrum archive,\u00a0 product evaluations and travels--not to mention an active family life. I had completely forgotten that\u2026","rel":"","context":"In &quot;Ham Radio&quot;","block_context":{"text":"Ham Radio","link":"https:\/\/swling.com\/blog\/category\/ham-radio\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2017\/12\/Airspy-HF-Plus-SDR.jpg?resize=350%2C200&ssl=1","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2017\/12\/Airspy-HF-Plus-SDR.jpg?resize=350%2C200&ssl=1 1x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2017\/12\/Airspy-HF-Plus-SDR.jpg?resize=525%2C300&ssl=1 1.5x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2017\/12\/Airspy-HF-Plus-SDR.jpg?resize=700%2C400&ssl=1 2x"},"classes":[]}],"jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/swling.com\/blog\/wp-json\/wp\/v2\/posts\/30450","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\/55"}],"replies":[{"embeddable":true,"href":"https:\/\/swling.com\/blog\/wp-json\/wp\/v2\/comments?post=30450"}],"version-history":[{"count":0,"href":"https:\/\/swling.com\/blog\/wp-json\/wp\/v2\/posts\/30450\/revisions"}],"wp:attachment":[{"href":"https:\/\/swling.com\/blog\/wp-json\/wp\/v2\/media?parent=30450"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/swling.com\/blog\/wp-json\/wp\/v2\/categories?post=30450"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/swling.com\/blog\/wp-json\/wp\/v2\/tags?post=30450"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}